A staff member in my office asked me which vitamin(s) I would recommend for her to take. She stated her energy was down and wanted to know the best vitamins. This is also a common question I get asked by patients. The staff member seemed a little surprised when I told her I didn't really recommend any vitamins.
There is little proof that vitamins (and other dietary supplements for that matter) can actually help you. On the contrary, if anything the evidence shows that vitamins might even harm you! I have blogged in the past about this, mentioning a review of 68 trials in over 200,000 patients published in February 2007 in JAMA showed that treatment with beta carotene, vitamin A, and vitamin E may increase your risk of death!
Benefits of vitamins like E and C were linked to their antioxidant properties, and have been suggested to prevent colds, improve memory and extend life. However, I have blogged previously about a study on Vitamin E and C that was published in the Journal of the American Geriatrics Society that studied thousands of seniors showing that this did not prevent dementia. In addition, an extensive review of the literature found that vitamin C did not prevent the common cold.
The list of studies goes on and on. There is just no convincing data that these things are helpful. Part of the reason may be that supplements work when you have a diet lacking vitamins and minerals. In the US, our diets are not healthy, but clearly we are getting some nutrition given that the majority of us are overweight or obese. There are a few exceptions where vitamins and supplements may actually help:
1. Folic acid for women of child bearing age. This prevents neural tube defects in babies .
2. Calcium. Calcium is recommend for most adult women to prevent osteoporosis. However, even here there is no data to support that calcium prevents fractures. Yet, it is an important part of bone metabolism, so it is recommended.
3. Vitamin D. We are learning more and more about Vitamin D. I have blogged before about a study published in the Annals of Internal Medicine showing that women with low vitamin D levels have a much greater risk of fracture than women with normal or high vitamin D levels, and it just today it was reported that a low level of vitamin D in older patients is associated with a higher risk of cognitive impairment.
Why Does it Matter?
So what? Even if there are no studies to prove that vitamins and supplements work, they are probably safe, and may help. This is for the most part true. In addition, one can argue that research is lacking because there is no financial incentive (unlike the drug companies) to do the research needed. However, I don't like to recommend things for patients which they will need to pay out of pocket for unless I know it will help them. Whereas some pharmacies are giving away generic antibiotics, and charging only $4 for some generic medications, some women's multivitamins sell for over $34 a bottle (and that's just at Target).
It's not clear whether or not vitamins really help. If you are a women of child bearing age, you should probably take calcium and folic acid. If you are a senior, you should probably take calcium and vitamin D. If you want to take a multi-vitamin, a generic, inexpensive, once daily mutli-vitamin should be fine. I would not take extra doses of other vitamins or supplements, especially vitamins A, C, or E.