Am I likely to develop vitamin D deficiency in winter -- and why is vitamin D essential for calcium absorption?

Our bodies create vitamin D from sunshine, and all we really need is 10 to 15 minutes of sunshine on our skin a day. During winter, we spend less time outdoors, and we’re bundled up against the cold. So some experts think the risk of vitamin D deficiency is higher in winter.

But year-round, many of us don’t get the Vitamin D we need. The National Institutes of Health recommends:

- 200 IU (international units) a day for adults under 50
- 400 IU a day for ages 51-70
- 600 IU a day for ages 70 or over.

Vitamin D plays a vital role in getting calcium into the bloodstream from the intestines and the kidneys. Without enough vitamin D, a lot of the calcium you take in from food or supplements could pass out of the body as waste.  If you don’t get outdoors a lot, ask your doctor about vitamin D supplements.