In A Heartbeat: Dr. Karl E. Bushman discusses vitamin D
The issue: Sellers of vitamin D claim the nutrient can lower blood pressure. Some studies recently suggested vitamin D lowers the risk of heart disease. Dr. Karl E. Bushman, an internist at St. Clair Hospital in Mt. Lebanon, answers questions about vitamin D.
Are there truly scientifically proven benefits to taking vitamin D?
The well-established benefits of vitamin D have to do with improved absorption of calcium that we eat and improved bone density as a result of calcium being deposited in the bones. Infants and children with extremely low vitamin D levels could get rickets, a bone development problem. Adults with very low vitamin D levels are more at risk for osteoporosis, which can lead to hip fractures or spine fractures. Many other benefits of vitamin D have been proposed, but the proof is not as strong.
Should people take any vitamin D at all?
The Institute of Medicine recommends 600 international units (iu) of vitamin D a day for people 1-70 years old and 800 iu for age 71 and up. Individuals with high risk or other diseases may require different doses based on their particular situation and medical evaluation. Moderate sun exposure helps vitamin D levels by converting less active forms to more active forms. Ten to 15 minutes of sun exposure at midday is a sufficient amount. Milk and orange juice have vitamin D fortification at 400 iu per liter (roughly a quart).
The bottom line? In this country, vitamins and dietary supplements do not need to prove safety or efficacy to be marketed. Vitamin D has much more research behind it that many supplements. Many people wonder if they should take a supplement because “they say it's good for you.” I suggest asking if “they” are people you trust, if the “good” proposed is something you want or need, and if taking it actually gives “you” the “good” you seek.