Vitamins and Supplements - an Update

We are often asked about various vitamins and supplements and when important information becomes available, we try to make blog posts to update everyone.  We’ve also decided to summarize our thoughts about supplements and this is the result of that effort, and we will update these recommendations as new information becomes available.  As always, the opinions expressed here are general recommendations and we always encourage a conversation with your physician before you make any changes to previously recommended treatments.

Multivitamins

There is general agreement among physicians that a well-balanced diet provides adequate vitamins and minerals required to maintain health and prevent diseases. Over half of Americans report that they regularly take dietary supplements in an effort to improve their health. Unfortunately, no studies have documented any benefit from multivitamin supplementation in healthy adults and safety concerns have been raised.

In November 2012, an article in Journal of the American Medical Association (JAMA) reviewed data collected from more than 14,000 male physicians ages 50 and over who were randomly assigned to either multivitamin or placebo daily.   Taking the multivitamin reduced the risk of neither heart attack, stroke, nor death from cardiovascular disease.

Specific vitamins and supplements

We do not recommend routine supplementation with vitamins A, C, E, folic acid or beta-carotene.

Taking antioxidant vitamins (such as vitamin C and vitamin E) has been promoted as beneficial in prevention of colds, heart attack, stroke and cancer. Unfortunately, none of these illnesses are prevented by taking vitamins. And worse yet, evidence has accumulated that antioxidant vitamins can be harmful.  

A remarkable study from Norway published in the New England Journal of Medicine in 2006 rebuffed prior theories that heart attacks could be prevented by antioxidant vitamins and was among the first to raise concerns that these might actually increase heart attack and stroke risk.  

Supplemental beta-carotene, vitamin A and vitamin E may increase risk of death according to a recent JAMA review.  

A study published in the Proceedings of the National Academy of Sciences demonstrated that taking supplemental vitamin C and vitamin E eliminated one of the major benefits of exercise in healthy men (in this case, the body’s ability to respond to insulin). 

There is no evidence that vitamin E is effective in preventing Alzheimer’s disease or other types of dementia.

A recent review of 67 studies (involving over 230,000 participants) concluded that vitamin C (alone or in combination with other vitamins) did not lower mortality. The same review concluded that vitamin E supplementation (as well as supplementation with vitamin A and beta-carotene) may increase mortality significantly.  

A study published in the Archives of Internal Medicine also concluded that the “more is better” approach is not necessarily the best.  They concluded that for adult women, multivitamins, vitamin B6, folic acid, iron, magnesium, zinc and copper all increased mortality in and that calcium supplementation decreased overall risk.

Another study published in the Journal of the American Medical Association also concluded that men who took 400 IU of vitamin E were 17% more likely to develop prostate cancer over 7 years than were those who did not take vitamin E.  An earlier study concluded that vitamin E supplementation increased the risk of death in men.

Studies in smokers have found that beta-carotene supplements increased lung cancer risk and the trace mineral selenium has been linked to an increased risk of skin cancer in women and men.

The exceptions

Deficiencies of vitamins B12 and D are linked to many health problems and when low levels are found in lab testing, we often recommend supplementation.  Also, many American adults should probably take a calcium supplement but there is some controversy in this recommendation.  

It is clear that vitamin D is important for bone health (to prevent osteoporosis). Recently, data have suggested that adequate vitamin D levels may also decrease the risk of falling, and prevent colon polyps and cancer and heart attack and may facilitate weight loss in those who are overweight. We’ve reviewed this data and while it’s unlikely that vitamin D is magic, it does seem to be important. Over-the-counter vitamin D supplementation is reasonable for average-risk patients who have a mild vitamin D insufficiency, but a much higher dose (prescription strength) supplement is probably more appropriate in patients at risk for osteoporosis or those with severe deficiency. 

Low levels of vitamin B12 can cause anemia and damage to the brain and nerve cells. Symptoms of nerve damage may be present before anemia. They can include numbness or tingling in the fingers and toes, poor balance and coordination, forgetfulness, depression, confusion, difficulty thinking and concentrating, impaired judgment and poor control of impulses, a decreased ability to sense vibration, ringing in the ears (tinnitus), and dementia, a decline in mental abilities that is severe enough to interfere with daily life.

The Bottom Line

With the few exceptions above, vitamin supplements are unnecessary and potentially harmful.  A well-balanced diet coupled with daily exercise is the closest thing to a magic pill for good health.

References

Seeso, H, et al.  Multivitamins in the Prevention of Cardiovascular Disease in Men; The Physicians' Health Study II Randomized Controlled Trial. JAMA 2012;308(17): 1751-60.

Bonaa KH, Njolstad I, Ueland PM, et al. Homocysteine Lowering and Cardiovascular Events after Acute Myocardial Infarction (the Norwegian Vitamin Trial - NORVIT).  N Engl J Med 2006;354:1578-88.

Bjelakovic G, Nikolova MA, Gluud LL, et al. Mortality in Randomized Trials of Antioxidant Supplements for Primary and Secondary Prevention, Systematic Review and Meta-analysis.  JAMA. 2007;297(8):842-857.

Mursu J, Robien K, Harnack LJ, Park D, Jacobs DR.  Dietary Supplements and Mortality Rate in Older Women: The Iowa Women's Health Study Arch Intern Med. 2011;171(18):1625-1633.

Mozaffarian D, Appel LJ, Van Horn L,  Components of a Cardioprotective Diet: New Insights Circulation. 2011;123:2870-2891

Isaac MGEKN, Quinn R, Tabet N, Vitamin E for Alzheimer's disease and mild cognitive impairment.  Cochrane Reviews.  http://www2.cochrane.org/reviews/en/ab00285.html

 

Miller ER, Pastor-Barriuso R, Dalal D, Riemersma RA, Appel LJ, Guallar E, Meta-Analysis: High-Dosage Vitamin E Supplementation May Increase All-Cause Mortality.  Ann Intern Med. 2005;142:37-46.

Written by: Scott W. Yates, MD, MBA, MS, FACP


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