Vitamins and Other Dietary Supplements

With a Healthy Diet, Few Children Need Them
The first rule is not to play doctor. Always get the advice of a pediatrician or other well-qualified healthcare professional about the dietary needs of infants and children to find out if supplements are indicated.

Dietary supplements are vitamins, minerals, amino acids, enzymes, herbs and other botanicals, and other substances that are added to a diet. A botanical is a plant or part of a plant that is valued for its supposed medicinal or therapeutic properties. Supplements include a variety of vitamins, minerals like calcium and iron, herbs such as echinacea and garlic; and specialty products like glucosamine, probiotics, and fish oils. They come in many forms, including pills, capsules, powders, drinks, or energy bars.1, 2, 3, 4

Because most supplements are not scientifically proven to be beneficial to health, many of them can be considered a type of “complementary” or “alternative medicine.” It should be kept in mind that in spite of its popularity, most alternative medicine is probably of no benefit beyond a placebo effect and almost certainly unproven to be of benefit to health.  Scientific evidence does indicate that for almost all people, both adults and children, eating a varied healthy diet, supplements are not needed and often are harmful.  Although many supplements are expensive and they are seldom needed, about half of Americans consume dietary supplements, many Americans give them to their children and we spend more than $34 billion annually on various forms of them.5

Vitamins are essential to human health but it is not well appreciated that large quantities added to the diet as supplements do not enhance health and may cause harm. People who frequently consume a high potency multivitamin or multimineral are at risk for excessive intake and the toxicity caused by an overdose of certain supplements. Since the body has limited storage capacity for many vitamins and other dietary supplements, if more than are needed for health are consumed, most are simply excreted.

Very few dietary supplements have been well tested for safety for use by infants or children.  Because most supplements have either been proven to be of no value, proven to be harmful, or need more study to determine if they are of any value, they should not be given to children without the explicit advice of a pediatrician of other competent healthcare professional.

With a few exceptions, such as pregnant women and infants, the guiding principal is to get the vitamins and minerals needed for health from a healthy diet.1

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How can supplements be sold if there is no scientific evidence of their value?
The answer is that the US Congress has responded to lobbying by the so-called “health food” industry and sharply curtailed the mandate of the Food and Drug Administration (FDA) to regulate dietary supplements. The result is that the regulations for dietary supplements are much less stringent than those for prescription or over-the-counter drugs. Unlike drugs, which must be approved as pure, safe and effective by the FDA before they can be marketed, the FDA does not determine whether dietary supplements are safe or effective before they can be sold.  Unlike prescription drugs that have labels, package inserts, advertising and health claims that must be approved by the FDA as scientifically sound, accurate and balanced, in that risks as well as benefits are described, advertising and information provided to consumers about dietary supplements does not require premarket review or approval by the FDA.1, 6

Under the Dietary Supplement Health and Education Act of 1994, the dietary supplement manufacturer is responsible for ensuring that a dietary supplement is safe before it is marketed. The FDA is responsible for taking action against any dietary supplement that turns out to be an unsafe product after it reaches the market. Dietary supplement labels may and often do carry unproven health-related claims, for example, that a dietary supplement addresses a nutrient deficiency, supports health, is good for body building, causes weight loss, or is linked to a particular body function, like strengthening the immune system or benefiting heart health. Labels with these types of claims must include the words, "This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease."  On a typical supplement label this language may not be easy to find.  It often can be found in small print, on an obscure part of the label, at an asterisk referring to the health-related claim.1, 4, 6

The FDA does have powers that can be useful in regulating supplements.  The FDA requires that manufacturers must follow good manufacturing practices (G.M.P.) to ensure the identity, purity, strength, and composition of their products. They can monitor information on the product's label and package insert and, at least in theory, make sure that information about the supplement's content is accurate and that any claims made for the product are truthful and not misleading.  And the FDA can require a recall of unsafe products.1, 4, 6

But independent testing has found that the strength of supplements may vary and the claimed contents may not be what is described on the label.  The contents may be different, diluted or even be missing entirely. Although the F.D.A. has the mandate to oversee the labeling and manufacture of supplements, it just does not have the funds or manpower to keep up with and appropriately monitor all supplements on the market.4

"There's a false perception that supplements fall under the same regulatory umbrella as prescription drugs," said Dr. Orly Avitzur, medical adviser for Consumer Reports. "That's not the case." "We really don't know what's inside."

A few supplements have obtained an independent evaluation and come with a written guarantee that the product is made under the FDA’s G.M.P. conditions, as well as a Certificate of Analysis (C.O.A.) that assures that the label accurately describes what the customer is buying. Consumers can also gain assurance from labeling that shows that the product has been “U.S.P. Verified.”  This proves the supplement has been inspected and approved under the United States Pharmacopeial Convention. Unfortunately, fewer than 1 percent of the 55,000 or so supplements on the market have been U.S.P. Verified.4

Paul A. Offit, chief of the division of infectious diseases , and Sarah Erush the clinical manager in the pharmacy department at the Children’s Hospital of Philadelphia, reached out to supplement manufacturers  for verification of G.M.P.  They found that about90 percent of the companies never responded, and of the remainder, many manufacturers refused to provide either a statement of G.M.P. or a C.O.A.; “in other words, they refused to guarantee that their products were what they said they were. Others lied; they said they met G.M.P. standards, but a call to the F.D.A. revealed they had been fined for violations multiple times.” Some manufacturers even willingly revealed that their product didn’t meet G.M.P. standards. The F.D.A. estimates that approximately 50,000 adverse reactions to dietary supplements occur every year. And yet few consumers know this.7

Offit and Erush concluded, “ …until the day comes when medical studies prove that these supplements have legitimate benefits, and until the F.D.A. has the political backing and resources to regulate them like drugs, individuals should simply steer clear.  For too long, too many people have believed that dietary supplements can only help and never hurt. Increasingly, it’s clear that this belief is a false one.” 9

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Are vitamins and other supplements effective in maintaining or improving health?
It seems sensible that any drug or dietary supplement should have a scientifically proven therapeutic benefit and its benefits should outweigh any risks to health. Scientific evidence shows that vitamins are essential to health, but with a few exceptions, the typical American diet supplies all the vitamins that are needed. Among the few dietary supplements that may be beneficial for overall health and useful for some people are calcium and vitamin D.  They are important for bone health and reducing bone loss.  Folic acid supplementation for pregnant women helps to prevent birth defects, and infants may need certain nutrients added to their diet depending on how and what they are fed.  Omega-3 fatty acids from fish oils might help some people prevent heart disease.  Almost all other supplements have either been proven to be of no value, proven to be harmful, or need more study to determine if they are of any value.  Most dietary supplements have not been well tested for safety, especially for use by pregnant women, nursing mothers, infants or children.10

This is especially true for plant-based supplements.  According to L. Bellows and R. Moore of Colorado State University: “Current research shows limited health benefits from taking herbal and botanical supplements, and no conclusive evidence that herbals should be used to treat or prevent any type of medical condition. There is no data to suggest that herbs are more beneficial than conventional drugs for treating illnesses.”  They note that “The body of well-controlled research is growing, but the short-term and long-term benefits and risks, as well as active or beneficial ingredients are still largely unknown.” 4

What about infants and children?
Never give an infant or child supplements that are not recommended by a pediatrician or other competent healthcare professional.  Keep in mind that other than recommended doses of vitamins, very few supplements have been tested in infants and children and there is reason to think that infants and children may be more susceptible than adults to the harms caused by high doses of vitamins and other dietary supplements.11

The American Academy of Pediatrics believes that after infancy healthy children receiving a normal, well-balanced diet do not need vitamin supplementation over and above the recommended dietary allowances, which includes 400 IU (International Units) of vitamin D a day in infants less than 1 year of age and 600 units/day for children over 1 year of age.  Megadoses of vitamins—for example, large amounts of vitamins A, C, or D—are of no benefit and can produce toxic symptoms, including nausea, rashes, headaches and sometimes other even more severe adverse effects on health.12, 13, 14

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Vitamins for breast and bottle fed babies11, 12, 13, 14, 15
Vitamins: human milk provides sufficient amounts of most vitamins, especially vitamin C, E, and the B vitamins. Vitamin D is an exception.  Although human milk contains small amounts of vitamin D, the American Academy of Pediatrics recommends that breastfed babies receive 400 IU of oral vitamin D drops until they are drinking vitamin D-fortified formula or milk. Most commercial formulas are fortified with vitamin D and other vitamins.  When a baby reaches one year old and is getting enough vitamin D from milk, extra vitamin D is no longer needed.  Thirty-two ounces per day of vitamin D-fortified formula or milk provides 400 IU a day of vitamin D. 

Iron: most babies are born with sufficient reserves of iron and breast feeding supplies enough easily-absorbed iron.  It is recommended that bottle fed babies get iron-fortified formula (containing from 4 to 12 mg of iron) from birth through the first year of life. Premature babies have fewer iron stores, so they often need additional iron beyond what they receive from breast milk or formula. 

When adding solid foods to a baby’s diet, it is advisable to choose baby foods such as cereals, meats, and green vegetables that contain supplemental iron.  Children between 6 months and 2 years and teenage girls, especially athletes, tend to be more susceptible to iron deficiency so ensuring an appropriate diet is important.

Calcium: adequate calcium intake during childhood and adolescence is important for the attainment of peak bone mass and the avoidance of osteoporosis later in life. Non-fat milk and vegetables, such as broccoli and spinach, are good sources of calcium. Some fruit juices are now fortified with calcium.

The American Academy of Pediatrics (AAP) recently warned adults not to give children or adolescents sport drinks or nutrition bars.  Because they are highly fortified, a child who regularly eats even “kid-friendly” nutrition bars regularly can get too much vitamin A, or too much vitamin B6. The nutrition that is vital to a child’s health and development is real food, including fruit, vegetables, and whole grains.

A well-rounded diet should deliver sufficient amounts of all the essential vitamins and minerals. Unless blood tests and a pediatrician’s evaluation reveal a specific deficiency, it’s preferable for children to obtain nutrients from food instead of from dietary supplements because unlike supplements, vegetables, fruits and grains contain phytochemicals—natural substances that are believed to help safeguard us from disease.

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Understanding nutritional recommendations and the amount of nutrients in food or supplements16
Potentially confusing different terms are used when referring to the amount of a particular nutrient (such as calcium or vitamin D) your body needs for good health and when measuring the amount of a particular nutrient in a serving of food or in a dietary supplement.

Recommended Dietary Allowances (RDAs) are the recommended daily intakes of a nutrient for healthy people, a value intended to meet or exceed the requirement for 97.5 percent of the population. They tell you on average how much of that nutrient you should be getting each day. RDAs are developed by the Food and Nutrition Board at the Institute of Medicine of the National Academies. They vary by age, gender and whether a woman is pregnant or breastfeeding; so there are many different RDAs for each nutrient.17

Tolerable Upper Intake Level (UL): As intake increases above the UL, the potential risk of adverse effects may increase. The UL is the highest average daily intake that is likely to pose no risk of adverse effects to almost all individuals in the general population.

Daily Values (DVs) describe how much (in percentage) of a nutrient a serving of the food or supplement provides in the context of a total daily diet.  DVs are established by the U.S. Food and Drug Administration, and are used on food and dietary supplement labels. For each nutrient, unlike the RDAs, there is one DV for all people ages 4 years and older. Therefore, DVs aren't recommended intakes, but DVs often match or exceed the RDAs for most people.

DVs are presented on food and supplement labels as a percentage.  For example the DV for calcium on a food label might say 20%. This means it has 200 mg (milligrams) of calcium in one serving because the DV for calcium is 1,000 mg/day.  The FDA has a Web page that lists the DVs for all nutrients.18

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Do Americans need more vitamin D and calcium?
Vitamin D and calcium are among the few supplements that may be helpful for some Americans and they are widely used.  Although only 10 to 15 minutes of sunshine 2-3 times weekly on hands, face and arms (without sunscreen) is needed for the skin to synthesize enough vitamin D to meet the body's requirements, recently there has been heightened concern among medical professionals that a large number of Americans are not as healthy as they could be because they are vitamin D deficient.  This concern was based on the widespread use of sunscreens, lack of sun exposure, and blood tests that were purported to show low blood levels of vitamin D.  To counter this supposed deficiency, many physicians began prescribing vitamin D supplementation. 

Because of the presumed widespread deficiency of vitamin D, the Institute of Medicine (IOM) was asked to evaluate the evidence linking vitamin D and health.  The IOM review panel noted: “… physicians have been ordering blood tests that seem to suggest, based on use of criteria that have yet to be validated, that many in our North American population are vitamin D deficient.”  The IOM committee “…assumed minimal sun exposure when establishing the Dietary Reference Intakes (DRIs) for vitamin D, and it deter­mined that 600 International Units (IUs) of vita­min D per day meets the needs of almost everyone in the United States and Canada. Peo­ple age 71 and older may need as much as 800 IUs per day because of potential changes in people’s bodies as they age.”19

 The IOM review panel documented that, based on nutritional surveys, the average total intake of vitamin D is below the median requirement, but “…data from these sur­veys show that average blood levels of vitamin D are above the 20 nanograms per milliliter that the IOM committee found to be the level that is needed for good bone health for practically all individuals. These seemingly inconsistent data suggest that sun exposure currently contributes meaningful amounts of vitamin D to North Amer­icans and indicates that a majority of the popula­tion is meeting its needs for vitamin D.” The Committee concluded that the prevalence of vitamin D inadequacy in North America has been overestimated. The IOM report went on to say “Nonethe­less, some subgroups—particularly those who are older and living in institutions or who have dark skin pigmentation—may be at increased risk for getting too little vitamin D.”

The IOM also considered calcium because, “…there is concern that some may not be obtaining sufficient amounts given the foods they eat. Calcium has been increasingly added to foods, and calcium supplement use, particularly among older persons, is widespread.”

According to the IOM, the “Recommended Dietary Allowances (RDA) for calcium for chil­dren ages 1 through 3 is 700 milligrams and 1000 milligrams daily is appropriate for almost all children ages 4 through 8.” The IOM noted that “Adolescents need higher levels to support bone growth: 1,300 mil­ligrams per day meets the needs of nearly all ado­lescents. For practically all adults ages 19 through 50 and for men until age 71, 1,000 milligrams covers daily calcium needs. Women over 50 and both men and women 71 and older need no more than 1,200 milligrams per day. National surveys in both the United States and Canada indicate that calcium may remain a nutri­ent of concern, especially for girls ages 9–18.”

The IOM concluded that calcium intakes over 2,000 milligrams per day increase the risk for harm, and that some postmenopausal women taking supplements may be getting too much calcium, thereby increasing their risk for kidney stones.

The IOM report warned: “As North Americans take more supplements and eat more of foods that have been fortified with vitamin D and calcium, it becomes more likely that people consume high amounts of these nutrients.”

The IOM looked at a variety of other health conditions possibly linked to lack of vitamin D and calcium.  They concluded that “Outcomes related to cancer/neoplasms, cardiovascular disease and hypertension, diabetes and metabolic syndrome, falls and physical performance, immune functioning and autoimmune disorders, infections, neuropsychological functioning, and preeclampsia could not be linked reliably with calcium or vitamin D intake.” 19

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Supplements do not prevent cardiovascular disease, or cancer or improve cognition
An important report from U.S. Preventive Services Task Force, released on February 25, 2014, examined the evidence about the effectiveness of vitamin, mineral, and multivitamin supplements for the prevention of cardiovascular disease and cancer.  The Task Force reviewed 3 trials of multivitamin supplements and 24 trials of single or paired vitamins.  The Task Force concluded that there was no clear evidence of a beneficial effect of supplements, including vitamins A, C, or D, folic acid, calcium (with or without Vitamin D), or selenium on all-cause mortality, cardiovascular disease, or cancer. 20

However, the Task Force did find that there was sufficient evidence to recommend against using either beta-carotene or vitamin E for the prevention of cardiovascular disease or cancer.  The evidence showed that there is no benefit to taking vitamin E, and that beta-carotene can be harmful because it increases the risk of lung cancer in people who are already at increased risk for lung cancer.

The Task Force concluded that for most people the best way to get the important nutrients essential for health is through a balanced diet rich in fruits, vegetables, whole grains, fat-free and low-fat dairy products, and seafood, a diet that has been associated with a reduced risk of cardiovascular disease and cancer.

Other careful studies have also found no benefits from supplements. The Physicians’ Health Study II (PHS II) evaluated the effects of vitamins on cardiovascular disease, cancer and cognition among male physicians, aged 65 or older.  After a follow up of 12 years the study found that taking beta carotene for cognition, and vitamins C and E for cardiovascular disease and for cancer, showed no meaningful benefits.21, 22, 23, 24, 25

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Are vitamin and other supplements safe? Are they harmful?
So if vitamin and other supplements seldom offer benefit to health it is appropriate to ask if they are just a waste of money or are they harmful?  Some vitamins appear to be harmless, even in high doses.  But many supplements contain active ingredients that can have powerful effects on the human body.  There is evidence that large doses of either single-nutrient supplements or high potency vitamin-mineral combinations may be harmful with potentially serious results.

Some supplements contain “megavitamins” and “meganutrients” that are 10 to more than 100 times the recommended Dietary Reference Intake (DRI) for a vitamin or mineral.  Very high doses of many supplements, especially the fat soluable vitamins A, and D, and vitamins C, and B6, offer no benefits and can cause serious health problems if taken regularly in large doses.  Among the severe side effects that can occur with consumption levels from 10 to over 100 times of the DRI are kidney stones, liver damage, nerve damage, birth defects, and even death.

 Another reason that taking supplements is seldom needed and overdosing may occur is because many of the ingredients found in dietary supplements are added to foods, including, milk, breakfast cereals and beverages.  In addition to the dose of a supplement, other factors such as body size, and how long the supplement is taken can influence toxicity.  Fat-soluble vitamins such as vitamins A, D, E and K are especially harmful in high doses because they are not as readily excreted as water-soluble vitamins.26

Vitamin A toxicity is unlikely when it is obtained from food.  But excess vitamin A from high potency multivitamin supplements can be toxic when consumed at a level over the Tolerable Upper Intake Level (UL) for adults of 3,000 mcg RAE. Symptoms of vitamin A toxicity include dry, itchy skin, headache, nausea, and loss of appetite. Signs of severe overuse over a short period of time include dizziness, and blurred vision. Vitamin A toxicity also can cause slowed growth, severe birth defects, reduced bone strength and may increase the risk for hip fractures.26

Vitamin D toxicity can occur when consumed at more than the Tolerable Upper Intake Level (UL) of 100 mcg (4000 IU) for people 9 years of age and older. Because many foods are fortified with vitamin D, high doses of vitamin D supplements should be avoided. Vitamin D is essential to the normal skeletal growth of children but excess consumption is particularly risky for them.26

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Excess vitamin D is stored in the liver and can cause toxicity with increased intestinal absorption of calcium that leads to high levels of calcium in the blood. High blood calcium can cause:26, 27

  1. Calcium deposits in soft tissues such as the heart and lungs
  2. Slowed mental and physical growth,
  3. Confusion and disorientation
  4. Damage to the kidneys
  5. Kidney stones
  6. Nausea, vomiting, constipation, poor appetite, weakness, and weight loss

Vitamin E obtained from food usually does not pose a risk for toxicity. Clinical trials have not only shown that supplemental vitamin E does not offer health benefits, but rather that it is associated with detrimental effects on health. Megadoses of supplemental vitamin E may pose a hazard to people taking anticoagulants by interfering with the action of medications such as Coumadin (warfarin) and statins.26

Although no Tolerable Upper Intake Level (UL) has been established for vitamin K, excessive amounts can cause the breakdown of red blood cells and liver damage. People on anticoagulants should consider moderating their intake of foods high in vitamin K, because excess vitamin K can alter blood clotting times.

Water-soluble vitamins that are easily excreted in urine are commonly thought of as harmless.  However, research shows that vitamin B-6 can cause nerve damage at the high doses sometimes prescribed for pre-menstrual syndrome (PMS).  High intakes of folic acid can mask or worsen the symptoms associated with a vitamin B-12 deficiency. Large amounts of vitamin C can cause nausea, kidney stones, gout, diarrhea, and rebound scurvy.  Consuming large doses of niacin supplements may cause flushed skin, rashes, and liver damage.28

High doses of other supplements can also cause problems, for example, excess iron causes nausea and vomiting and may damage the liver and other organs.  Some dietary supplements interact with certain prescription and over-the-counter drugs in ways that might cause harm. For example, St. John's wort can speed the breakdown of many drugs (including antidepressants and birth control pills) and thereby reduce these drugs' effectiveness; ginkgo taken with ibuprofen may lead to spontaneous and/or excessive bleeding; and high doses of garlic may enhance the effects and adverse effects of anticoagulant and antiplatelet drugs including aspirin, and clopidogrel (Plavix).2

Herbal supplements are especially not recommended for those who may be immuno-compromised (such as the elderly or those with HIV), those with kidney damage or liver disease, anyone who may be undergoing surgery or other invasive procedures, pregnant or lactating women, or children under the age of six.2

The FDA has issued a warning for the following herbs.  They are considered toxic, and should be avoided by everyone:29

  1. Aristolochic Acid–kidney damage and a carcinogen. It may be found in products with guan mu tong, ma dou ling, birthwort, Indian ginger, wild ginger, colic root, and snakeroot.
  2. Chapparal–irreversible liver damage.
  3. Comfrey–liver toxicity, carcinogenic effects, and damage to fetus if used during pregnancy.
  4. Ephedra/ma huang (ephedra sinca)–hypertension, myocardial infarction (MI), seizure, stroke, psychosis.
  5. Germander–liver damage and death.
  6. Kava–liver damage, especially risky for those with liver problems.
  7. Lobelia (Indian tobacco)–breathing problems, rapid heartbeat, low blood pressure, coma, or death.
  8. Magnolia-stephania preparation–kidney disease and permanent kidney failure.
  9. Willow bark–Reye’s syndrome in children, and allergic reaction in adults.
  10. Wormwood–seizures, numbness of legs and arms, delirium, and kidney failure.
  11. Yohimbe–hypotension (low blood pressure), heart conduction disorders, kidney disorders, nervous system disorders, death.

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The independent product testing organization, Consumer Reports (CR), worked with experts from the Natural Medicines Comprehensive Database, that is also an independent research group, to identify a dozen supplement ingredients (out of nearly 1,100 in the database) linked to the most serious adverse events by clinical research or case reports. CR easily found all of them for sale in June 2010 when they shopped for them online and in stores near their Yonkers, N.Y., headquarters.

The dozen are aconite, bitter orange, chaparral, colloidal silver, coltsfoot, comfrey, country mallow, germanium, greater celandine, kava, lobelia, and yohimbe. The CR study noted that the FDA had warned about at least eight of them, some as long ago as 1993.

When CR asked why these products were still for sale they found: “Two national retailers we contacted about specific supplements said they carried them because the FDA has not banned them.”  CR also noted that “Most of the products we bought had warning labels, but not all did. A bottle of silver we purchased was labeled "perfectly safe," with an asterisked note that said the FDA had not evaluated the claim. In fact, the FDA issued a consumer advisory about silver (including colloidal silver) in 2009, with good reason: Sold for its supposed immune system "support," it can permanently turn skin bluish-gray."30

Many studies suggest that not only are they of no benefit, long-term use of vitamins and other supplements increases the risk of cancer, cardiovascular disease and “all cause” death rates.

In his book Do You Believe in Magic? The Sense and Nonsense of Alternative Medicine, Dr. Paul A. Offit describes a series of major studies that evaluated the health effects of a variety of vitamins and other supplements, in particular the theory being tested was that antioxidants would be beneficial to health.  The findings were not what the advocates of vitamin therapy expected.5 These studies were carried out in adults but there is no reason to believe that the harmful effects of supplements would not be equally or even more detrimental to children.

In one study those taking vitamin E, beta-carotene, or both, were more likely to die from lung cancer or heart disease than those who didn't take them.  Another study found that study subjects taking vitamin A, beta-carotene, or both, were dying from cancer at a rate 28 percent higher and heart disease at a rate 17 percent higher than those who didn't take the vitamins.5, 31

A large study of people who took vitamins A, C, E, and beta-carotene found no evidence that antioxidants could prevent intestinal cancers, rather they found that death rates were 6 percent higher in those taking vitamins.5, 32 Offit cites other studies that have found an increased risk of death and heart failure associated with supplemental vitamin E.33

 “In 2008, a review of all existing studies involving more than 230,000 people who did or did not receive supplemental antioxidants found that vitamins increased the risk of cancer and heart disease.”34, 5

In another 2007 study, The Journal of the American Medical Association reviewed mortality rates in randomized trials of antioxidant supplements. In 47 trials involving 181,000 participants, mortality was 5 percent higher among those using the antioxidants vitamin A, beta carotene and vitamin E.  The studies did not detect a mortality effect of vitamin C or selenium.35

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A January 2009 editorial in The Journal of the National Cancer Institute noted that most studies of vitamins had shown no cancer benefits, but some had shown unexpected harms. Two studies of beta carotene found higher lung cancer rates, and another study suggested a higher risk of precancerous polyps among users of folic acid compared with those in a placebo group.36

A study published in 2011 in the Archives of Internal Medicine assessed the use of vitamin and mineral supplements in relation to total mortality in 38,772 older women in the Iowa Women’s Health Study. Sixty-six percent of women participating in the Iowa Women’s Health Study used at least one dietary supplement daily in 1986; in 2004, the proportion increased to 85%. Moreover, 27% of women reported using four or more supplemental products in 2004.37

The Iowa study found that use of multivitamins, vitamin B6, folic acid, iron, magnesium, zinc and copper were all associated with increased risk of death. There was a 2.4 percent increase in absolute risk for multivitamin users, a 4 percent increase associated with vitamin B6, a 5.9 percent increase for folic acid, and increases of 3 to 4 percent in risk for those taking supplements of iron, folic acid, magnesium and zinc.  The study authors concluded that “in older women, several commonly used dietary vitamin and mineral supplements may be associated with increased total mortality risk; this association is strongest with supplemental iron. In contrast to the findings of many studies, calcium is associated with
decreased risk." 37

Yet another study concluded that antioxidants, folic acid, and B vitamins are harmful or ineffective for chronic disease prevention.  And although Vitamin D supplementation was an issue that needed more research, current widespread use is not based on solid evidence that benefits outweigh harms.38

An editioral titled “Enough Is Enough: Stop Wasting Money on Vitamin and Mineral Supplements” in the Annals of Internal Medicine concluded: “The message is simple: Most supplements do not prevent chronic disease or death, their use is not justified, and they should be avoided. This message is especially true for the general population with no clear evidence of micronutrient deficiencies, who represent most supplement users in the United States and in other countries.”39

The editorial concluded: “…β-carotene, vitamin E, and possibly high doses of vitamin A supplements are harmful. Other antioxidants, folic acid and B vitamins, and multivitamin and mineral supplements are ineffective for preventing mortality or morbidity due to major chronic diseases--supplementing the diet of well-nourished adults with (most) mineral or vitamin supplements has no clear benefit and might even be harmful. These vitamins should not be used for chronic disease prevention. Enough is enough.”37

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What are the vitamins we need and where can we get them?
The evidence is now clear: vitamins derived from food sources are essential to health but with a few exceptions, additional vitamins and other dietary supplements are either of no value or are harmful to health. Requirements for vitamins may be expressed in different mathematical units. Close attention should be paid to ensure that similar units are being compared.

What are water-soluble vitamins?
Water-soluble vitamins dissolve in water and are not stored by the body. Since they are eliminated in urine, the body requires a fairly continuous daily supply of the B-complex group and vitamin C in the diet. Even so, deficiency of the B vitamins and vitamin C is rare in the United States.  Water-soluble vitamins are easily destroyed during food storage or washed out during food preparation. To reduce vitamin loss, fresh produce should be refrigerated, and milk and grains kept away from strong light.28  

B-complex vitamins
Eight of the water-soluble vitamins are known as the vitamin B-complex group: thiamin (vitamin B1), riboflavin (vitamin B2), niacin (vitamin B3), vitamin B6 (pyridoxine), folate (folic acid), vitamin B12, biotin and pantothenic acid. The B vitamins are found in many foods. They function as coenzymes that help the functioning of many of the body’s metabolic processes including those relating to obtaining energy from food. The B vitamins are also important for normal appetite, vision, skin health, the nervous system, and red blood cell formation.  However, consumption of large amounts of vitamin B-complex and vitamin C supplements and multivitamins are not recommended. Excesses of these vitamins have no known benefit.28

Thiamin: Vitamin B1
Good Food Sources of thiamin include peas, and legumes.  Thiamin is also found in foods that are not recommended because of their high fat content including pork and liver. Thiamin is found in whole grains but lost when grains are processed.  However many processed grain products such as cereal, bread, pasta, and rice, are fortified or enriched.  Nutrients commonly added to these products include thiamin (B1), niacin (B3), riboflavin (B2), folate and iron.28

Riboflavin: vitamin B2
Good Food Sources for Riboflavin include eggs, dark green vegetables, legumes, whole and enriched grain products, and milk. Foods should be protected from ultraviolet light because it is known to destroy riboflavin.28

Niacin: vitamin B3, nicotinamide, nicotinic acid
Good Food Sources for Niacin include peanuts, whole and enriched grain products. Vitamin B3 is also found in liver, fish, poultry, and meat, foods that are not recommended because of their high fat content.28

Vitamin B6: pyridoxine, pyridoxal, pyridoxamine
Good Food Sources for Vitamin B6 include whole grains and cereals, legumes, and green, leafy vegetables. For infants, breast milk and most infant formulas contain enough vitamin B6. Vitamin B6 is also found in meat, a food that is not recommended because of its high fat content.28

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Folate: folic acid, folacin
Good Food Sources for Folate include dark green leafy vegetables, whole grains, fortified grains and cereals, legumes, and citrus fruits. If whole grain products have a nutrition label it will show which ones are fortified with folate.  Folate deficiency in women who are pregnant may result in the delivery of a baby with neural tube defects such as spina bifida. Folate is also found in liver and meat, foods that are not recommended because of their high fat content.28

Vitamin B12: cobalamin
Vitamin B12 can only be found in foods of animal origin such as meats, liver, kidney, fish, eggs, milk and milk products, oysters, and shellfish. Consumption of non-fat dairy products is a recommended way to avoid vitamin B12 deficiency. Deficiency can also be avoided by consuming fortified foods or supplements that contain vitamin B12.28

Vitamin B12 deficiency is most common among strict vegetarians (vegans--those who eat no animal products), infants of vegan mothers, and the elderly. Symptoms of deficiency include anemia, fatigue, neurological disorders, and degeneration of nerves resulting in numbness and tingling. Some people develop a B12 deficiency called pernicious anemia because the stomach does not make enough of a protein, called intrinsic factor (IF), that is necessary for the intestines to properly absorb vitamin B12.  This cause of vitamin B12 deficiency can be treated with vitamin B12 injections.28


Good Food Sources for Biotin include milk, most fresh vegetables, yeast breads and cereals. Biotin is also made by intestinal bacteria and found in liver, kidney, and egg yolk, foods that are not recommended because of their high fat content.28

Pantothenic acid
Good Food Sources for Pantothenic Acid include whole grains, and legumes. Pantothenic Acid is also made by intestinal bacteria and found in liver, kidney, meats and egg yolk, foods that are not recommended because of their high fat content.28

Vitamin C: ascorbic acid, ascorbate
Good Food Sources for Vitamin C include citrus fruits and many common plant foods.  One orange, or 6 oz. of grapefruit juice provide enough vitamin C for a day. Some conditions may warrant an increase in vitamin C intake, such as exposure to cigarette smoke, environmental stress, growth, and sickness.  Although rare in the United States, vitamin C deficiency may occur in alcoholics, the elderly, and in smokers.28

Propelled by advocacy by two-time Nobel Prize winner Linus Pauling, mega doses of vitamin C have been recommended to prevent cancer and to prevent or cure the common cold.  But there is no evidence that this therapy is effective. Studies suggest that mega doses of more than 500 mg of vitamin C per day do not increase a body’s overall level of vitamin C and mega doses of vitamin C should be avoided.5, 28

Fat-soluble vitamins: A, D, E, and K26
Unlike water-soluble vitamins that need regular replacement, the fat-soluble vitamins, vitamins A, D, E and K, are stored for long periods in the body’s liver and fat and are only slowly eliminated from the body. Diseases caused by a lack of fat-soluble vitamins are unusual in the United States and very few people need to supplement their diet with these vitamins. Because they are not readily excreted in urine, excessive consumption of fat-soluble vitamins generally pose a greater risk for toxicity than water-soluble vitamins.  They are not destroyed by cooking and eating a normal, well-balanced diet will not lead to toxicity but supplements that contain mega doses of vitamins A, D, E and K may.

Some health problems may decrease the absorption of fat, and in turn, decrease the absorption of vitamins A, D, E and K. The decision to use supplements of these vitamins should only be made on the advice of a medical professional.

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Vitamin A: retinol

The healthiest source of Vitamin A is from plant-based foods that contain the antioxidant, beta-carotene, which the body converts to vitamin A. Beta-carotene, is found in fruits and vegetables, especially those that are orange or dark green in color. Examples of good vitamin A sources include carrots, pumpkin, winter squash, dark green leafy vegetables and apricots.  The retinol, retinal, and retinoic acid forms of vitamin A are supplied primarily by foods of animal origin such as dairy products, fish and liver.26

Vitamin D

Vitamin D increases the amount of calcium absorbed from the small intestine and plays a role in the body’s metabolism of calcium and phosphorous, the immune system and regulation of cellular growth.  Especially for children, adequate amounts are essential to the healthy formation and maintenance of teeth and bone.26

The primary food sources of vitamin D are milk and other dairy products fortified with vitamin D. Vitamin D is also found in oily fish (e.g., herring, salmon and sardines) as well as in cod liver oil. In addition to the vitamin D provided by food, the skin synthesizes vitamin D in response to sunlight.  A person can obtain adequate vitamin D through exposure to the ultraviolet B in sunlight on hands, arms and face without sunscreen for 10 to 15 minutes two or three times a week.26

How much Vitamin D
19, 26, 27
The Recommended Dietary Allowance (RDA) for vitamin D appears as micrograms (mcg) of cholecalciferol (vitamin D3) (Table 1). From 12 months to age fifty, the RDA is set at 15 mcg. Twenty mcg of cholecalciferol equals 800 International Units (IU), which is the recommendation for maintenance of healthy bone for adults over fifty. Table 1 lists additional recommendations for various life stages.

The IOM review panel considering requirements for vitamin D concluded that available scientific evidence supports a key role of calcium and vitamin D in skeletal health.  Based on bone health, Recommended Dietary Allowances (RDAs; covering requirements of ≥97.5% of the population) for calcium range from 700 to 1300 mg/d for life-stage groups at least 1 yr of age.19

For vitamin D, RDAs of 600 IU/d for ages 1-70 yr and 800 IU/d for ages 71 yr and older, corresponding to a serum 25-hydroxyvitamin D level of at least 20 ng/ml (50 nmol/liter), meet the requirements of at least 97.5% of the population. The Committee concluded that the prevalence of vitamin D inadequacy in North America has been overestimated.  They noted that teenage girls may get inadequate calcium and that excessive use of vitamin D and calcium supplements are of concern.19

Some other populations are potentially at risk of vitamin D deficiency and may require extra vitamin D in the form of supplements or fortified foods. They include:19, 27

  • Exclusively breast-fed infants: Human milk only provides 25 IU of vitamin D per liter. All breast-fed and partially breast-fed infants should be given a vitamin D supplement of 400 IU/day

  • Dark Skin: Those with dark pigmented skin synthesize less vitamin D upon exposure to sunlight compared to those with light pigmented skin.

  • Elderly: This population has a reduced ability to synthesize vitamin D upon exposure to sunlight, and is also more likely to stay indoors and wear sunscreen which blocks vitamin D synthesis.

  • Covered and protected skin: Those who cover all of their skin with clothing while outside, and those whi wear sunscreen with an SPF factor of 8, block most of the synthesis of vitamin D from sunlight.

  • Disease: Fat malabsorption syndromes, inflammatory bowel disease (IBD), and obesity are all known to result in a decreased ability to absorb and/or use vitamin D in fat stores.

In all of these circumstances a blood test to see if the serum 25-hydroxyvitamin D level is less than the IOM recommended minimum of 20 ng/ml (50 nmol/liter), and the advice of medical professional is needed to determine if supplementation is necessary and the amount needed.19

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The Recommended Dietary Allowance (RDA) for vitamin D indicates how much of vitamin D most people should get on a daily basis:40

0 - 6 months: 400 IU (10 micrograms (mcg) per day)
7 - 12 months: 400 IU (10 mcg/day

1 - 3 years: 600 IU (15 mcg/day)
4 - 8 years: 600 IU (15 mcg/day)

Older children and adults
9 - 70 years: 600 IU (15 mcg/day)
Adults over 70 years: 800 IU (20 mcg/day)
Pregnancy and breast-feeding: 600 IU (15 mcg/day)

In general, people over age 50 need higher amounts of vitamin D than younger people.

Vitamin D toxicity almost always occurs from using too many supplements. The safe upper limit for vitamin D is:
1,000 to 1,500 IU/day for infants
2,500 to 3,000 IU/day for children 1 - 8 years
4,000 IU/day for children 9 years and older, adults, and pregnant and breast-feeding teens and women.

Calcium, bone health and osteoporosis 41, 42, 43, 44, 45
The role of calcium and vitamin D in bone health are important because of their role in prevention of osteoporosis and the widespread prevalence of osteoporosis. Osteoporosis or "porous bone" is a condition of the skeletal system characterized by low bone mass and the deterioration and weakening of bone tissue. Osteoporosis leads to an increased risk of bone fractures typically in the wrist, arm, hip, and spine.

The skeletal system is not static and throughout life bone is remodeled, especially in response to stress from weight bearing and physical activity. In a continuous process, existing bone is resorbed and new bone is formed. For example, bed rest promotes bone resorbtion and weight bearing exercise promotes bone formation. During childhood and teenage years, new bone is formed and bones become larger, heavier, and denser. Bone formation outpaces resorption until peak bone mass, defined as maximum bone density and strength, is reached around age 30. Adequate calcium consumption and weight bearing physical activity strengthen bones, optimizes bone mass, and may reduce the risk of osteoporosis later in life.

After about age 30, bone resorption slowly begins to exceed bone formation. Osteoporosis can occur when bone resorption occurs too quickly or when bone formation occurs too slowly. Among women, bone loss is most rapid in the first few years after menopause.

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Osteoporosis: Prevalence
Osteoporosis is very common. According to the International Osteoporosis Foundation, osteoporosis and low bone mass are currently estimated to be a major public health threat for about 50 million American women and men aged 50 and older and each year there are an estimated 10 million new osteoporotic fractures in the U.S.39

Worldwide, 1 in 3 women over 50 will experience osteoporotic fractures, as will 1 in 5 men with common fractures being of the forearm, humerus, hip and spine. In women over 45 years of age, osteoporosis accounts for more days spent in hospitalization than many other diseases, including diabetes, myocardial infarction and breast cancer. The combined lifetime risk for hip, forearm and vertebral fractures coming to clinical attention is around 40%, equivalent to the risk for cardiovascular disease. Falls contribute to fractures - 90% of hip fractures result from falls. A third of people over age 65 fall annually, with approximately 10-15% of falls in the elderly resulting in fracture, and almost 60% of those who fell the previous year will fall again.41

Symptoms42, 44
Osteoporosis is often called a silent disease because bone loss occurs without symptoms. People may not know that they have osteoporosis until their bones become so weak that a sudden strain, bump, or fall causes a hip to fracture or a vertebra to collapse. Collapsed vertebrae may initially be felt or seen in the form of severe back pain, loss of height, or spinal deformities such as stooped posture (kyphosis).

Detection42, 44
A health care provider may recommend a measurement of bone mass using a bone mineral density (BMD) test. BMD tests can identify osteoporosis, help estimate the risk of future fractures and measure response to osteoporosis treatment. The most widely recognized BMD test is a dual-energy x-ray absorptiometry, or DXA test. With a low exposure to radiation it can measure bone density at hip and spine.

Risk factors42, 44
Many conditions associated with an increased risk of the development of osteoporosis are known, and many people with osteoporosis have several risk factors, but others who develop the disease have no known risk factors.

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Among the Risk Factors You Cannot Change

  • Gender. Women are more likely to develop osteoporosis than men. Women have less bone tissue and lose bone faster than men, especially after menopause.

  • Age. The risk of osteoporosis increases with advancing age because bones gradually become thinner and weaker as you age.

  • Body size. Small, thin-boned women are at greater risk.

  • Ethnicity. Caucasian and Asian women are at highest risk. African American and Hispanic women have a lower but significant risk.

  • Family history. Heredity may play a role in that people whose parents have a history of fractures also seem to have reduced bone mass and may be at increased risk for fractures.

Risk Factors You Can Change

Weight-Bearing Physical Activity. A sedentary lifestyle is an important risk for osteoporosis and exercise is an important component of an osteoporosis prevention and treatment program. Bone responds to exercise by becoming stronger, especially to weight-bearing exercise that works against gravity. Examples include walking, hiking, jogging, basketball, soccer, climbing stairs, weight training, tennis, and dancing. Adequate weight-bearing physical activity early in life is also important in reaching peak bone mass. In addition to improving bone health, physical activity increases muscle strength, coordination, and balance, and reduces the risk of falls and other accidents that cause fractures.

Recommended physical activity guideline for adults are at least 30 minutes of moderate physical activity most, but preferably all, days of the week. Children should engage in at least 60 minutes of moderate physical activity most, but preferably all, days of the week. Adequate levels of calcium intake can maximize the positive effect of physical activity on bone health during the growth period of children. Childhood and adolescence are particularly valuable times to improve bone mass through exercise. Some young females, particularly those training for elite athletic competition, exercise too much, eat too little, and consequently experience amenorrhea which makes them at risk for low bone mass and fractures. Studies have shown that bone mineral density in postmenopausal women can be maintained or increased with therapeutic exercise.47, 48, 49

Smoking can lead to lower bone density and higher risk of fracture and this risk increases with age.50

Alcohol intake. Excessive consumption of alcohol increases the risk of bone loss and fractures. Regular consumption of as little as 2 to 3 ounces a day of alcohol may cause skeletal damage, even in young women and men. The risk of vertebral and hip fractures in men increases greatly with heavy alcohol intake, particularly with long-term intake. People who drink heavily are at increased risk of fractures both because of bone loss and increased risk of falling. 40, 42, 51, 52

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Nutrition: Protein, Calcium and vitamin D
In addressing the causes of osteoporosis, the important role of excessive animal protein in increasing the loss of calcium in the urine has not received much attention. Increased urinary excretion of calcium and therefore loss of calcium from bone is not associated with plant protein ingestion but rather with high levels of animal protein that create a heavy acid load in the blood. This acid load requires mobilization of calcium from bone to neutralize it. Ingestion of high levels of salt, sugar, caffeine, alcohol and exposure to nicotine all also increase calcium loss in the urine. Studies show that fruit and vegetable intake is positively associated with increased bone density in men and women--they help neutralize the acid load from animal protein and reduce loss of calcium. 53, 54, 55, 56, 57

Studies show that high levels of animal protein, more than 20 gm/day, can lead to a negative calcium balance even when a considerable amount of milk and other dairy products or even calcium supplements are consumed. An analysis of thirty-four separate surveys comparing fracture rates for women in different countries showed a high correlation between increased risk of fractures and increased consumption of animal protein. Although consumption of milk and other calcium-rich dairy products in America is relatively high, osteoporosis is common and studies about the usefulness of milk in prevention of osteoporosis have had conflicting results.42, 44, 58, 59

For example, a 20-year study conducted in Sweden found that women who drank more than three glasses of milk a day were more likely to suffer a broken bone and were at twice the risk of dying at the end of the study than those who drank less. A similar but less pronounced trend was found in men. However an opposite pattern was found for fermented milk products such as yoghurt suggesting a role of the sugars in milk. It would seem that the calcium Americans consume only partially makes up for the high levels of calcium lost in the urine caused by high consumption of animal protein.

An inadequate supply of calcium from a diet low in calcium and vitamin D over a lifetime also contributes to the development of osteoporosis. Many studies show that low calcium intake appears to be associated with low bone mass, rapid bone loss, and high fracture rates. Other studies show that vitamin D supplementation can reduce rates of bone loss and also fracture rates in older male and female adults, and the elderly. In institutionalized elderly women, this combined calcium and vitamin D supplementation reduced hip fracture rates. Studies in children and adolescents have shown that supplementation with calcium, dairy calcium-enriched foods or milk enhances the rate of bone mineral acquisition.41, 61, 62

However a recent review by the U.S. Preventivie Medicine Task Force (USPSTF) suggests that routine use of vitamin D and calcium supplementation by postmenopausal women is not of proven value. 63

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Other Less Common Risk Factors for Osteoporosis

  •  Sex hormone abnormalities. Abnormal absence of menstrual periods (amenorrhea), low estrogen level (menopause), and low testosterone level in men predispose to osteoporosis
  •  Anorexia nervosa. Characterized by an irrational fear of weight gain, this eating disorder increases the risk for osteoporosis. The onset of anorexia nervosa frequently occurs during puberty, the time of life when maximal bone mass accrual occurs, thereby putting adolescent girls and boys with anorexia nervosa at high risk for reduced peak bone mass64, 65
  • Certain medications cause bone loss: Several medications can contribute to bone loss. For example, the long-term use of glucocorticoids (medications prescribed for a wide range of diseases, including arthritis, asthma, Crohn’s disease, lupus, and other diseases of the lungs, kidneys, and liver) can lead to a loss of bone density and fracture. Bone loss also can result from long-term treatment with certain antiseizure drugs, such as phenytoin (Dilantin) and barbiturates; gonadotropin-releasing hormone (GnRH) drugs used to treat endometriosis; excessive use of aluminum-containing antacids; certain cancer treatments; and excessive thyroid hormone.

Prevention: What you can do to protect your bones is not complicated 42, 44

  • Get enough calcium from plant-based foods
  • Get enough vitamin D, preferably from sunshine
  • Engage in regular weight bearing exercise
  • Avoid smoking
  • Avoid alcohol or at least limit it to 2-3 drinks a day

Sources of calcium

National nutrition surveys show that many people consume less than half the recommended amount of calcium. Food sources of calcium include non-fat dairy products, such as milk and yogurt, but the best sources are plant-based.  Good plant-based sources of calcium include dark green, leafy vegetables, such as broccoli, collard greens, bok choy, and spinach; collard greens, turnip greens, kale, okra, chinese cabbage, dandelion greens, and mustard greens. Other sources include sardines and salmon with bones; tofu; almonds; and foods fortified with calcium, such as orange juice, cereals, soy beverages, and breads.

Calcium needs change during one’s lifetime. The body’s demand for calcium is greater during childhood and adolescence, when the skeleton is growing rapidly, and during pregnancy and breastfeeding. Postmenopausal women and older men also need to consume more calcium. Also, as the body ages, it becomes less efficient at absorbing calcium and other nutrients. Older adults are also more likely to have chronic medical problems and to use medications that may impair calcium absorption.  Although most people can get adequate calcium from food, depending on how much calcium is available from food in a person’s diet, a calcium supplement may be recommended by a health professional.

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Recommended calcium intakes:

Life-stage group


Infants 0 to 6 months


Infants 6 to 12 months


1 to 3 years old


4 to 8 years old


9 to 13 years old


14 to 18 years old


19 to 30 years old


31 to 50 years old


51- to 70-year-old males


51- to 70-year-old females


70 years old


14 to 18 years old, pregnant/lactating


19 to 50 years old, pregnant/lactating


Source: Food and Nutrition Board, Institute of Medicine, National Academy of Sciences, 2010.

The safe upper limit for calcium is:

  1. 1,000 mg/day for infants 0 to 6 months
  2. 1,500 mg/day for infants 6 to 12 months
  3. 2,500 mg/day for children 1 - 8 years
  4. 3,000 mg/day for children and teens 9-18 years including pregnant and breast-feeding teens
  5. 2,500 mg/day for adults 19-50 years including pregnant and breast-feeding women
  6. 2,000 mg/day for adults 51 years and older

Vitamin E: tocopherol
Vitamin E benefits the body by acting as an antioxidant, and it was theorized that antioxidants, and vitamin E supplements in particular, might help prevent heart disease and cancer. Substantial research now indicate that people who take vitamin E and other antioxidant supplements are not better protected against heart disease and cancer than non-supplement users and may be harmed by large doses of vitamin E.  Many studies do show that regularly eating an antioxidant rich diet full of fruits and vegetables, may lower the risk for heart disease, cancer, and other diseases.  The evidence indicates that antioxidants and phytonutrients should be obtained from plant-based foods, fruits and vegetables, not as supplements.26

Food sources for vitamin E
The best sources of vitamin E are from fruits and vegetables, grains, nuts (e.g., almonds and hazelnuts), seeds (e.g., sunflower) and fortified cereals.  Although 60 percent of vitamin E in a typical diet comes from vegetable oil (soybean, corn, cottonseed, and safflower) and products such as margarine and salad dressing that are made with vegetable oil, these sources of vitamin E should be kept to a minimum to facilitate a healthy low-fat diet.26

Vitamin K
Vitamin K is naturally produced by the bacteria in the intestines, and plays an essential role in normal blood clotting.  Inadequate amounts of vitamin K can lead to hemorrhaging.  Good food sources of vitamin K are green, leafy vegetables such as turnip greens, spinach, cauliflower, cabbage and broccoli.  Vitamin K is also found in certain vegetables oils including soybean oil, cottonseed oil, canola oil and olive oil but this source of vitamin K should be kept to a minimum to facilitate a healthy low-fat diet.  Animal foods, in general, contain limited amounts of vitamin K. 26

Newborn babies lack the intestinal bacteria to produce vitamin K and need a supplement for the first week of life.  Vitamin K deficiency may also occur in people who take anticoagulants, such as Coumadin (warfarin), are on antibiotic drugs when they alter or kill intestinal bacteria, and in people with chronic diarrhea. In all of these circumstances the advice of physician is needed to determine if supplementation is necessary and the amount needed.26

The essential facts1

  1. Most individuals can obtain all the vitamins and minerals needed to meet the recommended dietary allowances and adequate intakes by eating a variety of foods.
  2. Dietary supplements, including multivitamins and multiminerals, do not guarantee protection against disease
  3. Large doses of either single nutrient supplements or high potency vitamin and mineral combinations may be harmful.
  4. Although vitamin deficiency is rare, it may occur when nutrients are limited in one’s diet, or as a result of a secondary deficiency caused by tobacco, alcohol use, or disease
  5. Consult a medical professional before taking any self-prescribed single nutrient supplements.

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