Prime Time - Jane Fonda [50]
We are designed to get vitamin D from the sun. In fact, anyone living north of a line drawn between Los Angeles and Atlanta is almost certainly not getting enough vitamin D from sunlight during much of the year. Modern lifestyle changes—including more indoor activities and sunscreen usage—have reduced or eliminated sun exposure for just about everyone, especially older people, causing unprecedented vitamin D deficiency, rickets, and bone breaks in children and adults alike. Compounding the problem of reduced sun exposure is the fact the there are so few food sources for vitamin D. An adequate intake simply cannot be obtained from food. Hence, a supplement is necessary for most people, especially since we know that too much sun exposure—normally the main source of vitamin D—is correlated with skin cancer.
Poor bone health is not the only consequence of inadequate Vitamin D. Evidence is starting to show that vitamin D may be important for every cell and every organ in your body, and that a deficiency may contribute to a host of diseases, from the common cold and the flu to cancer, hypertension, insulin-dependent diabetes, and even multiple sclerosis.
How much vitamin D is enough? That’s debatable, as even the scientists cannot decide!
Foods with vitamin D are fortified milk and oily fish from the sea (such as salmon and mackerel), egg yolks, liver, and fish liver oil. It is difficult to get enough vitamin D from food sources alone, so people up to age seventy should supplement with at least 600 IU daily. For those over seventy, 800 units daily is recommended, with a safe upper limit of 4,000 units. To find out what you should be taking, get your vitamin D blood levels tested at your next doctor’s appointment. Blood levels of at least 32 to 40 nanograms per milliliter or higher are recommended. When choosing a supplement, look for vitamin D3 (cholecalciferol), not D2 (ergocalciferol). You can usually get vitamin D as part of a calcium supplement.
CALCIUM
Sources of calcium are dairy products, broccoli, kale, and collards, as well as calcium-fortified foods like orange juice, soy milk, breakfast cereals, and tofu. Assuming we are getting about 700 milligrams of calcium from our daily diet—a big assumption for most people—doctors recommend that in order to help protect our bones, we should supplement this with 500 milligrams of calcium. The new guidelines from the Institute of Medicine recommend a total of 1,200 milligrams of calcium for women fifty-one and older and men seventy-one and older. Too much calcium can result in kidney stones and heart disease; the institute says that the upper limit of safety for men and women over fifty-one is 2,000 milligrams. Calcium supplements need to be taken along with 800 to 1,000 IU of vitamin D—or more—to help with absorption and to reduce bone loss and prevent fractures. (More on calcium in Appendix IV.)
I used to think that vitamin E, vitamin C, and selenium were the antioxidant supplement superstars. I was wrong! There are, in fact, no well-controlled trials showing that supplementing our diets with vitamin E or selenium does any good … and it may do harm.
VITAMIN C
Vitamin C is an important antioxidant, synthesizes collagen, helps boost iron absorption, and plays a role in our hormonal and nervous systems. The recommended dietary allowance is 75 milligrams per day for adult women and 90 milligrams per day for men. When a person eats up to 120 milligrams daily, 80 to 90 percent is absorbed. As supplemental vitamin C intake goes up, absorption declines. There is no evidence that older people need megadoses, and everyone should avoid doses greater than 2,000 milligrams daily, which may cause diarrhea, nausea, abdominal cramps, and nosebleeds.
Food sources include citrus fruits, peaches, strawberries, peppers, broccoli, Brussels sprouts, papayas, kohlrabi, mangoes, pineapple, kiwifruit, peppers, cauliflower, cabbage, kale, potatoes, asparagus,