“Wonder Bread helps build strong bodies 12 ways.” Remember that advertising slogan? The “miracle bread” of my childhood was reputed to be a key to good health, due to its fortification with vitamins and minerals–which were the “12 ways” it was going to help you become Superwoman.
Fast forward 40 years or so, and we find something new that’s going to “build strong bodies 12 ways.” Though vitamin D’s not new, certainly, it’s getting a fresh look in the press. And for good reason. Turns out it helps prevent a host of maladies–including breast cancer–and we may not be getting nearly enough of it.
Vitamin D has an amazing array of positive effects on your health. Looked at another way, its absence brings with it a host of medical problems. Like calcium and phosphorus deficiency: without vitamin D, only about 10-15% of the calcium you ingest is absorbed by your body. So what, you say? Try osteoporosis. Which leads to bone fractures and muscle weakness. Add type I diabetes, multiple sclerosis, Crohn’s disease, hypertension, vascular disease and cancer–all shown to be related to vitamin D deficiency–and you understand why this under-appreciated vitamin is in the spotlight.
Dr. Michael Holick, an internationally recognized expert in vitamin D, and director of Boston Medical Center’s Bone Healthcare Clinic, has written an overview of his work in the July 19 issue of the New England Journal of Medicine. In it he says that up to a billion people worldwide are probably not getting sufficient vitamin D in their diets. And that’s a problem.
Not as readily available in natural food sources as some other vitamins (think vitamin C and citrus fruits), vitamin D is mainly available to us through fortified milk. Oh, and oily fish. A 6-ounce can of tuna will give you your daily requirement. Problem is, who’s going to eat a can of tuna every day? Or gag down a tablespoon of cod liver oil (which would give you more than enough vitamin D… but at what cost to your taste buds?) In addition, Dr. Holick claims the current recommended adequate intake for vitamin D, 400IU, is far short of what his studies have determined to be a truly effective amount: 800-1000IU daily (uh, that would be TWO cans of tuna a day…).
So, what’s a woman to do? First, think sunlight, which allows vitamin D to be synthesized right in your skin. According to the National Institutes of Health, “Ten to fifteen minutes of sun exposure at least two times per week to the face, arms, hands, or back without sunscreen is usually sufficient to provide adequate vitamin D.” The NIH adds that this exposure “should be followed by application of a sunscreen with an SPF of at least 15 to protect the skin.” (After all, you don’t want to ward off breast cancer only to develop skin cancer.)
Problem is, not all of us live far enough south for this amount of exposure to do the trick. Winter sunlight in Boston isn’t strong enough to produce significant vitamin D. Taking it a step further, women who live at high latitudes, where the sun’s rays are weak year-round, are more likely to die of breast cancer than women exposed to stronger rays at lower latitudes. So exposure to sunlight may not be enough.