Beverly Vaughn, MD, medical coordinator for the Menopause and You program shares this timely update on the importance of vitamin D and how it affects the body.

How's Your D?

Most of us are familiar with the fact that we need calcium to nourish our bones. Just as a reminder, the requirement is 1000 mgs for premenopausal women, 1200 mgs for those postmenopausal women who take hormones and 1500mgs for those who don't. But what about vitamin D?   How important is it?

You may have noticed an increase in news articles on the benefits of D. Its importance for the skeletal system isn't new, remember Ricket's?  You can only absorb a small (<15%) portion of the calcium you take in without vitamin D. In addition, it acts in an intricate balance with parathyroid hormone, a key factor in bone metabolism. Researchers are finding that it may be linked to multiple other body functions including the immune system, cardiovascular system, mental health and longer life span. Its role in limiting cell growth may explain why adequate levels are important for inhibiting cancers such as breast and colon. Vitamin D deficiency has been associated with congestive heart failure as well as depression and schizophrenia.
 
 It's becoming more apparent that many individuals are deficient in vitamin D. Some studies have found that at least 50% of older adults have subnormal blood levels of D. This is particularly true for those who live in the northern hemispheres, those of darker skin, and people who spend a lot of time indoors. UV B radiation stimulates the skin to produce vitamin D. Exposure to this type of sunlight is less in the northern climes. Individuals with more skin pigment do not absorb UV B radiation efficiently. The skin of older adults loses some of its capacity to make vitamin D. In order to get adequate exposure you need to get into the midday sun 2 - 3 times a week for up to 30 minutes without sunscreen. The sun isn't the only way to get vitamin D. There are dietary supplements, and foods such as salmon, egg yolks, fortified milk and cereals. Vitamin D3 cholecalciferol, is the best choice for bone health. If you are at high risk for skin cancer you may want to get your D from these alternative sources.

Healthy levels of D are 30 - 40 ng of 25 hydroxyvitamin D. Deficiency levels are less than 20 ng. The suggested daily requirement for D has recently been raised to 800 IU - 1000 IUs . Most multiple vitamins and calcium that have D added do not meet this requirement. This means you have to do a little extra work reading labels and may have to buy vitamin D separately to ensure that you meet your requirement.

There is disagreement among experts as to whether everyone should have their 25 hydyroxyvitamin D level tested. It does make sense to test individuals with certain chronic medical problems because the illness or the treatment may increase the risk of having inadequate D. Women who have osteopenia or osteoporosis should make sure that their levels are normal before starting on bisphosphonates (Fosamax ®, Actonel ®, Boniva®).

Vitamin D may not be the way to the fountain of youth but it is clear that it is an integral part of many health systems. So be sure to get your D!