Vitamin D improves our health—if we get enough.

Stronger bones, a better immune system, protection from some cancers, lower blood pressure, clearer skin, and a healthier brain. These are just a few of the apparent benefits of the strangest of vitamins—vitamin D. Unlike all other vitamins, vitamin D is made by our bodies, but it requires sunshine.

The problem is, we’re just not getting as much sun as we used to or enough to make the vitamin D our bodies need. We spend too much time indoors, and when we do go outdoors, we’re using sunblock, which blocks the ultraviolet rays that create vitamin D.

Our skin is an amazing organ that automatically regulates the amount of vitamin D it produces, and it naturally won’t produce too much. If you spent a day at the beach, your skin would produce about 10,000 IU (international units) of vitamin D3. That’s about the maximum daily production by your skin. Based on the existing research and an equal measure of common sense, here’s an approach to make sure you’re protected and getting enough vitamin D:

• Get your vitamin D from a combination of food, sunshine, and supplements.

• Spend less time indoors and more time outdoors.

• When you’re out in direct sunshine, use sunblock, especially on areas that have already had ample sun exposure, like your face, ears, neck, chest, arms, and hands. Always try to avoid getting a sunburn, children especially. It’s okay to get 10 to 15 minutes of sun daily before you apply sunblock.

• Enjoy healthy foods that contribute to your vitamin D intake, like salmon, sardines, and other fish; and fortified dairy and soy milk products.

• Take a daily supplement of vitamin D3—around 1000 IU per day—depending on your needs.

• Get your blood level of vitamin D checked at your next physical. It should be between 30ng/ml and 100ng/ml.

To learn more about the health effects of vitamin D supplementation, the government has funded a $20 million study that has just begun. Both vitamin D and fish oil will be rigorously studied to see whether supplements can reduce your risk of cancer, heart disease, or stroke.