VITAMIN PILLS
Before there were pills, there was food. And as a general rule, the best way to get your daily vitamin requirement is in foods, which often are rich in several vitamins as well as fiber and other health-giving substances. Twenty years ago doctors believed that the typical U.S. diet provided adequate vitamins, and that very few of us needed to take vitamin pills. In the United States and other developed nations, full-blown vitamin-deficiency diseases have been rare for decades because most people eat foods that prevent them. In recent years, however, modest vitamin deficiencies have been implicated in a variety of illnesses, including heart disease, cancer and birth defects. As a result, an increasing number of experts recommend daily vitamin pills. There are three substances in particular that people need to be sure they get enough of: folic acid, vitamin B12 and vitamin D.
Folic acid, when taken early in pregnancy, reduces the risk of birth defects in the baby’s brain and spine. Folic acid should be taken every day, and by all women of childbearing age–since women may not know they are pregnant in the critical first weeks of pregnancy. There is also evidence that higher levels of folic acid may reduce the risk of heart disease and colon cancer in all adults, and breast cancer in women who consume alcohol. Although more foods are being fortified with folic acid, some people still do not get enough in their diet. We recommend that all women of childbearing age take a pill with at least 400 micrograms daily.
Vitamin B12 is important for the health of blood cells and nerves. Inadequate levels can cause anemia, numbness in the arms and legs, memory loss and confusion. Vitamin-B12 deficiency also may increase the risk for heart disease and strokes. Vegans are vulnerable because they do not eat meat, poultry, fish, milk, cheese and eggs–key dietary sources of vitamin B12. Adults over 50 are also at risk because they often have difficulty absorbing vitamin B12 from food. For these groups, a multivitamin or B12 pill each day is a good idea.
Vitamin D is essential in helping to absorb calcium from food, and directly aids the growth and strength of bones and teeth. A new study suggests that low levels of vitamin D could be related to the nonspecific aches and pains that plague many people. And researchers are studying the theory that vitamin-D deficiency makes people vulnerable to multiple sclerosis. Only fatty fish and dairy products fortified with vitamin D provide it in the diet. You need increasing amounts as you get older, and people living in the northern part of the Northern Hemisphere are particularly vulnerable to deficiency–because our bodies make vitamin D in response to sunlight. Women over 50 should definitely take a pill with 400 international units (IU) of vitamin D daily–the amount in a typical multivitamin pill. It’s probably a good idea for men over 50 as well. Doses of more than 2,000 IU daily can be toxic.
CALCIUM
There’s no debate about whether you need calcium in your diet. You absolutely do. But experts disagree on how much calcium you need and the best food sources of it. Calcium gives bone its strength; about 99 percent of the calcium in your body is in bone. Osteoporosis–a disease that thins bones–afflicts about 10 million people in the United States, and leads to more than 300,000 broken hips per year. One quarter of older adults with hip fractures die within a year. Current U.S. recommendations for calcium are 1,000mg a day for people ages 19 to 50, 1,200mg a day for people 51 and older and 1,300mg a day for pregnant or breast-feeding women.
Following these guidelines will ensure that your body gains more calcium than it loses each day. If you believe, as nutrition experts did for many years, that you can’t get too much calcium, only too little, then these numbers seem reasonable. Some recent research, however, indicates that high amounts of calcium in the diet may increase a man’s risk for prostate cancer. And even though it makes sense that a high level of calcium in the diet should reduce the risk of fractures, there’s not much evidence that it does. Observational studies, in which large numbers of people record what they eat periodically over many years, come to conflicting results: getting a lot of calcium probably does make bones more dense, but fracture rates do not decrease.
There is disagreement as well about the best food sources of calcium. The most common dietary source, of course, is milk. There’s a lot of easily absorbed calcium in milk: 300mg in every eight-ounce glass. But milk also contains extra calories, a lot of saturated fat (“bad” fat) and the sugar lactose. About 50 million adults in the United States, and the majority of adults on the globe, have trouble digesting lactose. Many other foods have calcium, including spinach and collard greens, although the mineral is not as readily absorbed from these as it is from milk. (For a list of calcium-containing foods, go to health.harvard.edu/NEWSWEEK.)
So what should you do? In our view, women over 50 should take a pill each day that contains 500mg to 1,000mg of calcium and at least 400 IU of vitamin D. It’s inexpensive, calorie-free and unlikely to cause any problems. The vitamin D increases the absorption of calcium, and is probably more important than calcium itself in preventing broken bones. We do not think that current evidence justifies routinely recommending a daily calcium pill for men over 50. If a man consumes no dairy products, 500mg would be reasonable. To reduce the risk of osteoporosis and the fractures that result from it, be as physically active as possible (activity builds bones), and eat at least one serving of dark green leafy vegetables a day. Such vegetables contain vitamin K, which recent research shows can also strengthen bones.
LYCOPENE We would love to tell you that pizza is health food. If it were, no doubt, the world would be a better place. Alas, most pizzas contain substantial amounts of “bad” carbohydrates and “bad” fats. However, they also contain at least one thing that is very good for you: lycopene, an antioxidant found in tomatoes and tomato products.
Since 1995 many studies have examined the possibility that lycopene in the diet, and lycopene levels in the blood, are connected to good health. Not all of the studies come to the same conclusion. However, in our judgment the largest and best studies indicate that a diet rich in lycopene may reduce the risk of prostate cancer in men by more than 30 percent, and may reduce the risk of prostate cancer that spreads to the rest of the body by 50 percent. Other studies find that diets rich in lycopene reduce the oxidation of LDL cholesterol (“bad” cholesterol), a critical early step in the development of cholesterol-clogged arteries. Theoretically, this could reduce the risk of heart attacks and strokes, although more research is needed.
Although the health benefits of high-lycopene diets are not yet proved, we think that a diet including tomato-based foods on most days of the week is a good idea–unless you have an allergy to tomatoes. Some fruits and vegetables tend to deliver optimal health benefits when they are eaten raw. Not so with tomato-based foods. You get more lycopene from cooked tomatoes, especially those cooked in oil, than from raw ones. Lycopene is increasingly being added to multi-vitamin pills; the bottles often sport the words WITH LYCOPENE. However, there is no substantial evidence that lycopene taken in pill form will provide the same benefits that it appears to provide when consumed in foodstuffs. So don’t take a vitamin pill just because it has lycopene in it. Instead, consider increasing the number of meals you eat each week that contain cooked tomato-based products. And don’t pig out on pizza in hopes of improving your health.
Adapted from “The Benefits and Risks of Vitamins and Minerals: What You Need to Know,” published by Harvard Medical School; “Eat, Drink and Be Healthy,” by W. C. WILLETT, M.D., with P. J. SKERRETT, Simon & Schuster Source, 2001, and the Harvard Health Letter. For more information visit health.harvard.edu.
