Now that it's almost summer, those of us who live in northern climates have the chance to soak up enough sun for our skin to make a healthy amount of Vitamin D. How do we get the right amount of sun exposure with the least risk of sunburn and skin damage?  

I have heard dermatologists say that no amount of sun exposure is good for the skin. However,  the Vitamin D Council says that a few minutes of exposure to a large enough area of your body (legs, back) can greatly boost your Vitamin D stores with lots of health benefits.  Here's an article by the Vitamin D Council about how to get the right amount of sunshine for Vitamin D, depending on your location, skin type, and other factors. As a rule of thumb, they recommend exposing your bare skin to the sun in midday for about half the time it takes for your skin to turn pink. After that, cover up your skin or go in the shade to prevent sunburn and skin cancer. 

I like to eat lunch outside in the summer - and take that opportunity to expose my arms and legs to the sun for about 10-15 minutes. When I don't get out in the sun and for the rest of the year in northern Illinois, I rely on Vitamin D capsules.  They are relatively inexpensive, small and easy to swallow. 

One other caution:  adults who are 65 years of age or older may not be able to make enough Vitamin D through skin exposure, so keep popping those supplements and ask your doctor to test your Vitamin D levels periodically.

Here's a nice summary article from Time Magazine about how to build bone during the years when your body is most able to do so - through about age 30. But these strategies also help those of us who are older to minimize bone loss.

One tip that was new to me was to watch caffeine:  a study showed that more than 18 oz. of coffee can negatively affect bone density.  This article also confirmed findings elsewhere that one glass of beer or wine per day may boost bone density, but two or more glasses can do the opposite.

Vitamin D is mentioned here and is worth discussing in more depth as we approach winter, which in northern climates, often brings weeks with little or no sunshine.  Vitamin D is essential to building bone, in addition to calcium and exercise. This comprehensive fact sheet from the National Institutes of Health covers amount needed, recommended blood levels of Vitamin D, food, supplement and sunshine as sources, etc.  
What you can do:
1. Get your vitamin D level checked. It should be between 50 and 100. 
2. If you are deficient in Vitamin D, you can take up to 4,000 iu daily.

When I first started trying to build my bone density (almost 20 years ago), the recommended amount of Vitamin D was 400 iu/day.  Ten years later, a chiropractor specializing in nutrition tested my Vitamin D levels and advised a daily dose of 5,000 iu of Vitamin D.  Since then, I've read and heard more doctors recommend between 2,000 and 5,000 ius per day, depending on the level as tested in the blood. Vitamin D deficiency is common in the U.S.

Does Vitamin D alone build bones?  No, but it is essential for calcium absorption. Common forms of Vitamin D are D2, added to milk, D3 supplements, and the D that our bodies manufacture with sunshine on bare skin.  Dr. Mercola, author of a popular health blog, recommends 15-20 minutes of sunshine as a superior means of obtaining Vitamin D or taking D3 supplements.  His article covers the role of other supplements, diet, and lifestyle on osteoporosis. 

Here's an informative article about the role of Vitamin D and Vitamin K  in building bone density through calcium absorption.