His and Her Vitamins -- Smart Medicine or Marketing Ploy? - Medical Myths - Harvard Commentaries

The answer seemed obvious: of course not. As a woman, you should buy the "Women's Health" version, while men should stick with the vitamin designed for them.

And that got me thinking: What are the differences between vitamins that are marketed to men versus women?

There are obvious anatomical differences between men and women. And those differences translate into different health needs.

Women need Pap smears to screen for cervical cancer, a condition men cannot develop.
There are a host of pregnancy-related health issues that do not affect men.
Iron-deficiency anemia is much more common in women due to blood loss during menstrual periods.
Men may develop prostate enlargement (causing urinary problems) and prostate cancer, conditions about which women need not worry.

There are also diseases that seem to affect men and women differently even when the anatomy is similar. Heart disease is a good example. Men tend to develop "typical" symptoms (including chest pressure or pain), while women may be more likely to complain of weakness or shortness of breath.

But how do gender differences in health and disease translate into the vitamins we should take?

Many people take a daily multivitamin as a sort of "insurance" to make up for the essential nutrients that could be missing from their diets. And many doctors recommend taking a multivitamin. But, it's reasonable to ask who needs to take a daily multivitamin.

In fact, only certain groups of people clearly need to take vitamins. Most of these people only need one or two specific vitamins, not the 20 or more contained in many multivitamins.

For people with a specific deficiency, such as iron deficiency anemia, a supplement makes sense. Supplements may be helpful for people in certain high risk groups:

Menopausal women – Everyone tends to lose bone with age. But women lose bone faster after menopause due to the hormonal changes. Women generally do not get enough calcium and vitamin D in their diets, so supplemental calcium and vitamin D are routinely recommended (along with weight-bearing exercise) to help build and maintain bone strength.
Pregnant women – Prenatal vitamins contain many nutrients. But the most important one is probably folic acid because it's been shown to reduce the incidence of birth defects.
Vegetarians – Strict vegans, especially, may not get adequate amounts of vitamin A, vitamin B2 (riboflavin), vitamin B12 and vitamin D from their diets.
The "nutritionally challenged" – Alcoholics and other people whose diets are inadequate may benefit from a daily multivitamin.

Let's get back to that vitamin commercial. When it comes to vital nutrients, men and women have similar, though not identical, needs. In fact, if you compare the average multivitamin designed for a woman with one marketed to men, you’ll find they are nearly identical.

I compared the ingredients for a leading brand of multivitamins that comes in several versions based depending on a person's age and gender. The ingredients for the one promoted to adult women were nearly identical to the one promoted to men. But, the amounts of vitamins varied. Of the vitamins listed, the amounts were identical for eight, slightly different for seven, and significantly different for only six. For example:

Only the woman's version had iron.
Calcium and vitamin D were found in significantly higher amounts in the women's version. This also makes sense as these may counter the tendency postmenopausal women have toward developing osteoporosis.
Only the men's version had lycopene and potassium. Lycopene is found in cooked tomatoes and has been linked with a reduced risk of prostate cancer (though never proven to lower risk when taken in a supplement). I can't think of a reason why men would need more potassium than women. (I contacted the company to find out, but did not get a reply.)
The men's vitamin had more selenium — 110 mcg or 157% of daily recommended dose — compared with the women's vitamin — only 20 micrograms, or 29% of the daily dose. Higher blood levels of selenium have been associated with lower prostate cancer risk in some studies. However, as with lycopene, it's not yet clear that taking extra selenium as a supplement will lower prostate cancer risk. In fact, a study published in December 2008 found that taking selenium supplements was not protective against prostate cancer. (In late 2009, a consumer group, the Center for Science in the Public Interest, sued over a vitamin maker's claims that their men's vitamin lowers the risk of prostate cancer. That suit is still pending, though the contested claims have recently been removed from advertisements and packaging of the vitamins.)
The men's vitamin had higher amounts of magnesium and B12 than the women's version. It's not clear to me why men would need more magnesium or B12 than women.

Overall, the differences in these multivitamins were minor. And where there were differences, they were not always based on good evidence.

Women who are not iron deficient do not need extra iron (and iron supplements can cause stomach upset or other problems in certain people).

Calcium and vitamin D supplements are already recommended for women whose diets do not contain adequate amounts. There's no need to take a multivitamin for that purpose. Besides, most multivitamins have less than the 1,000 milligrams to 1,200 milligrams per day that's recommended to help them maintain healthy bones.

Vitamins are commonly considered a safe, inexpensive way to make sure your intake of vital nutrients is adequate. But for many people, they are a waste of effort — and money.

For women, calcium, vitamin D and, for some, iron are the big players. For most men, it's not clear that taking a multivitamin will improve health.

In my view, highlighting how important it is for men and women to take different vitamins is more about marketing than improving health. So talk to your doctor about your particular situation and nutritional needs. You may find that the question is less about which multivitamin is best and more about whether you need to take one at all.

Robert H. Shmerling, M.D. is associate physician at Beth Israel Deaconess Medical Center and associate professor at Harvard Medical School. He has been a practicing rheumatologist for over 20 years at Beth Israel Deaconess Medical Center. He is an active teacher in the Internal Medicine Residency Program, serving as the Robinson Firm Chief. He is also a teacher in the Rheumatology Fellowship Program.