Vitamins and Minerals
Vitamins are compounds that your body needs but cannot manufacture on its own (with the exception of vitamin D, which is produced by your skin when exposed to sunlight). As noted in part one, “The Healthy Man,” there are two types of vitamins: fat-soluble and water-soluble. The fat-soluble vitamins—A, D, E, and K—can be stored by your body in the fat inside your cells. Taking large doses of these vitamins can be risky because they can build up in your body and cause unwanted effects. Water-soluble vitamins, composed of the eight B vita- mins and vitamin C, are not stored by your body and need to be replaced every day in the food you eat.
The antioxidants (see page 9) vitamin C, beta carotene (which your body con- verts into vitamin A), and vitamin E have been getting a lot of publicity because of their supposed disease-preventing qualities, prompting some people to take large—in some cases massive—doses of antioxidant supplements. However, much of the scientiﬁc research that has been done on antioxidants remains con- ﬂicting, so doctors still recommend getting most of your antioxidant vitamins from the foods you eat, rather than from supplements.
Minerals are chemicals that plants absorb from soil and water. Small amounts of many of these minerals are essential for normal body function. When you eat fruits, vegetables, and grains, you receive the beneﬁt of the minerals they con- tain. Two important minerals are calcium and iron. Calcium is important for building strong bones and preventing the bone-thinning disease known as osteo- porosis. Too much calcium can cause health problems such as constipation and kidney stones. Men between ages 25 and 65 should take in about 1,000 mil- ligrams of calcium per day. Men over 65 should take in about 1,500 milligrams of calcium per day. Low-fat and nonfat dairy products are excellent sources of calcium. Adequate iron intake ensures that your red blood cells have enough hemoglobin, a compound needed to transport oxygen throughout the body. However, too much iron has been linked to an increased risk of heart and liver disease in men. You need only about 10 milligrams of iron per day. Good sources of iron include red meat, raisins, nuts, and enriched breads, cereals, rice, and pasta.
Vitamin and mineral deﬁciencies are rare in the United States. Although many men take vitamin and mineral supplements, the best way to get your daily allowances of these nutrients is from the food you eat. This is another reason why it is so important to consume a wide variety of foods—to ensure a balanced diet.