Bone Health and Vitamin D

About the Author – This “Health Update” was written by John J. Mast, M.D., C.M.D., associate medical director, Masonic Village at Elizabethtown

More than 10 years ago, our children and grandchildren were taught vitamin D plays a very important role in the absorption of calcium and the formation of bone.

Unfortunately, our diets are generally low in vitamin D. The only foods rich in vitamin D include wild fish, which has a lot of fat, sun-dried Shiitake mushrooms and wild reindeer meat – foods most people rarely, if ever, consume. Thus, most of the vitamin D ingested orally comes from fortified foods, although the food sources usually do not have adequate amounts of vitamin D to meet our daily requirements.

Exposure to sun is a much more efficient, although higher-risk, method to achieve high levels of vitamin D in the blood stream. A fair-skinned adult sunbathing in the summer can achieve about 20,000 units of vitamin D in 30 minutes. This would be the equivalent of drinking 200 glasses of milk, since there are 100 IU of vitamin D in eight ounces of milk. One also needs to remember the amount of vitamin D produced through sun exposure depends upon many contributing factors. They include the latitude where one is living, season of the year, time of the day, air pollution, cloud cover, melanin content of the skin, use of sunblock, age and the amount of clothes one is wearing at the time of sun exposure.

We Need More Vitamin D
Until recent years, few physicians considered testing for vitamin D deficiency. Yet, we now know many people are deficient but aren’t aware of it. Physicians are learning common musculoskeletal complaints like muscular weakness, a feeling of pain or heaviness in the legs, fatigue or easy tiring may be symptoms of vitamin D deficiency. Recently, geriatricians have learned older adults with vitamin D deficiency experience more frequent falls and fractures. Obtaining a blood test which measures the vitamin D level is the most effective method to determine vitamin D deficiency.

How much vitamin D one should take orally, in a multivitamin, in order to achieve an acceptable blood level? While authoritative nutritional sources have recommended 400 IU daily for many years, we now know most people will likely require at least 1,000 IU daily unless they have daily sun exposure at least 15 minutes during the middle of the day. Other published sources suggest one may need to take up to 10,000 IU of vitamin D daily to increase blood levels to 50 ng/ml. This is especially true in obese adults.

Vitamin D deficiency is very common, especially in those who have limited sun exposure. Not only does vitamin D affect the strength of our bones and muscles, but it also has an effect on all of our body tissue and organs. Do not hesitate to talk to your physician about the importance of vitamin D, as well as how much vitamin D you should be taking daily. There are times blood levels may be helpful in determining the amount of vitamin D needed to supplement the vitamin D produced by sun exposure.