Vitamin D has been in the news a lot lately. Each new study that is done involving vitamin D demonstrates how important it is for a wide variety of bodily functions. It has long been recognized that vitamin D was necessary for proper absorption of calcium, but it was not thought to have any other intrinsic value. Also, the possibility of toxicity and overdose caused resistance to supplementation. 

     It has now become clear that vitamin D is necessary for a myriad of bodily functions. Seasonal affective disorder is almost always a result of deficiency. Hair, skin and nails need vitamin D for proper growth and development. It has been shown to be protective against a variety of cancers, as well as being important for blood sugar control. Muscle aches, arthritis and fatigue can all be symptoms of inadequate vitamin D levels.

    In the past, most vitamin D came from sun exposure. Fears of skin cancer have caused many people to limit their time in the sun, which has caused widespread deficiency in the population.


     Darker skin blocks the absorption of sun rays resulting in even lower blood levels of vitamin D, so supplementation is vital for these populations. These same patient populations have increased risks of diabetes and cancer so vitamin D supplementation is doubly important to them.

     When having your vitamin D level checked, make sure the correct test is ordered- it should be 25 (OH) Vitamin D. Studies show that lifeguards have vitamin D levels of about 80, which seems to be where the body naturally plateaus even with ongoing sun exposure. Based on this, it is believed that the optimal level is between 50 and 80. To achieve this most patients need daily dosing of 2,000-10,000 IU of vitamin D3 (taken with a fat containing meal for maximal absorption) or at least 15 minutes of unprotected sun daily. Professional brand supplements come in 2,000-5,000 IU caps, which make for easy dosing. In the Berkshires, winter sun will not provide you with any significant amounts of vitamin D, so don’t count on it to be enough. 

    It can be confusing to decide on a daily supplement routine- there are so many vitamins that are important. However, since almost everyone needs extra vitamin D, go ahead and add several thousand units daily, and have your doctor monitor you to make sure you are taking enough. What you are getting in your multivitamin is not enough!

Ardis Fisch MD