There was a two-for-one special on your girlfriend's multivitamin and you're almost out of your own. Can you just take hers? What's the big difference between men's and women's multivitamins?
Not much. Men need more of certain nutrients and less of others. With only one exception, taking a women's multivitamin isn't likely to be a problem.
Men can use women's multivitamins if they choose formulas that are low in or free from the mineral iron. Increased iron stores may raise the risk of coronary heart disease.
Men's and Women's Vitamins
As with most things today, you have a lot of choices when it comes to vitamins. Supplement manufacturers now offer formulas for women, men and older adults. These claim to provide amounts of nutrients that offer special benefits for each gender and age group.
The one-a-day men's formula of one major brand of multivitamin provides more of most vitamin and minerals than the women's multivitamin. It's especially high in the mineral selenium, and it contains the antioxidant nutrient lycopene which may help protect against prostate cancer, according to the National Institutes of Health.
The women's version has more of the B vitamin folate, which is crucial for women in their childbearing years to prevent birth defects, according to Johns Hopkins Medicine. The women's version also provides more iron; pre-menopausal women have an increased need for this mineral due to losses during menstruation.
RDAs for Men and Women
Having separate multivitamin formulas for men and women makes sense, since the recommended dietary intakes for many vitamins and minerals are different. Besides needing less folate and iron, men need more of many vitamins and minerals.
For example, men need 900 micrograms of vitamin A, while women need 700 micrograms, according to the National Academies of Medicine. Men need 15 more milligrams daily of vitamin C, an extra 30 milligrams of vitamin K and an additional 3 milligrams of zinc. They also need more niacin, riboflavin, thiamin, choline and chromium.
Risk of Too Much Iron
Men won't quite get the RDA of many nutrients by taking a women's multivitamin, but that's not a health risk. The main problem for men taking women's multivitamin supplements is getting too much iron. A women's multivitamin with the RDA for iron — 18 milligrams — provides more than double the 8 milligrams men need each day.
Iron serves many important functions in the body. But, as with many nutrients, too much can have negative effects. Iron catalyzes the body to produce reactive radicals that can damage cells and lead to inflammation and disease in the body. At normal levels, this isn't a problem; however, excess iron intake can build up in the body, causing blood levels to increase.
Oxidative stress caused by reactive radicals has been linked to atherosclerosis, or hardening and narrowing of the arteries, according to a study published in the International Journal of Preventative Medicine in August 2013. Atherosclerosis can lead to the development of coronary artery disease in men, who are at a greater risk of developing the disease than women, reports Mayo Clinic.
What's a Man to Do?
If you need a multivitamin, your best bet is just to pop out to the store and pick up some vitamins made just for you. But if you decide to take a women's multivitamin, make sure it doesn't contain more iron than you need. Not all women's supplements contain the entire RDA for the mineral.
However, keep in mind that even if the vitamin is lower in iron than the RDA for women, it may still have too much iron for you. If you eat a lot of iron already in your diet, you can easily go overboard.
This is especially true if you eat a lot of red meat, which can contain up to 4 milligrams of iron per 2.5-ounce portion, according to the Dietitians of Canada. Duck meat contains even more, with up to 7.5 milligrams of iron in 2.5 ounces. Organ meats are the richest source of dietary iron with as much as 10 milligrams in 2.5 ounces.
The type of iron found in animal foods is called heme iron, which is absorbed more easily than the iron in plant foods. Even though some plant foods are high in iron — lentils have up to 5 milligrams per three-fourths cup cooked — the iron isn't as readily available because your body has to convert it into a form it can use.
While heme iron is the best source of the mineral for those people who need to boost their stores, it can be risky for men who already have high levels from supplementation. According to a meta-analysis in the Journal of Nutrition in March 2014, in 21 studies involving 292,454 participants, heme iron intake, specifically, was associated with an increased risk of coronary heart disease.
Read more: The 12 Most Overrated Supplements
Do You Need a Multivitamin?
The truth is, you may not need to worry so much whether a women's multivitamin is OK to take. Many experts say there's really no benefit to popping a daily pill, and research shows that multivitamins don't live up to the hype that they can help prevent disease.
A research review in the Annals of Internal Medicine in December 2013 that analyzed data from studies involving nearly 400,000 participants found limited evidence that taking multivitamins reduces the risk of cancer or heart disease. Study results, also published in Annals of Internal Medicine in December 2013, found no cognitive benefits of long-term multivitamin use in 6,000 men over age 65.
In light of this, improving your diet is likely a better bet than stealing your girlfriend's vitamins. People think of multivitamins as a sort of "nutritional insurance," but they can't make up for a healthy diet. While women of childbearing age may need supplemental folic acid, most people can get all the nutrition they need simply by eating a variety of healthy foods.
Instead of spending money on supplements, people are better off investing in nutrient-rich, high-quality foods, including:
- Fresh fruits and vegetables, organic if possible
- Hormone-free, grass-fed beef and dairy
- Hormone-free, cage-free poultry and eggs
- Fresh fish and seafood
- Whole grains
- Nuts, seeds and beans
- Healthy sources of fat such as olive oil and avocado
Eating three meals a day and avoiding non-nutritive junk foods that crowd out healthier foods increases the likelihood of meeting your daily nutrient requirements.
Tackling Nutrient Deficiencies
Even, if you are deficient in a particular nutrient, you don't necessarily need a multivitamin. First of all, it's important to visit your doctor to get your blood tested and an official diagnosis. If your doctor determines that you do have a deficiency, short or long-term supplementation might be recommended to address the specific deficiency.
However, in the case of a deficiency, it's only necessary to replace the nutrient you're lacking. Taking a multivitamin on top of that may just give you a lot of additional stuff your body doesn't really need.
- NIH: "Prostate Cancer, Nutrition, and Dietary Supplements (PDQ®)–Health Professional Version"
- National Academies of Medicine: "Summary Tables, Dietary Reference Intakes"
- International Journal of Preventive Medicine: "Relation Between Body Iron Status and Cardiovascular Risk Factors in Patients With Cardiovascular Disease"
- Mayo Clinic: "Arteriosclerosis / Atherosclerosis"
- Dietitians of Canada: "Food Sources of Iron"
- Iron Disorders Institute: "Iron We Consume"
- Journal of Nutrition: "Dietary Iron Intake and Body Iron Stores Are Associated With Risk of Coronary Heart Disease in a Meta-Analysis of Prospective Cohort Studies"
- Annals of Internal Medicine: "Vitamin and Mineral Supplements in the Primary Prevention of Cardiovascular Disease and Cancer: An Updated Systematic Evidence Review for the U.S. Preventive Services Task Force"
- Annals of Internal Medicine: "Long-Term Multivitamin Supplementation and Cognitive Function in Men: A Randomized Trial"