Vitamin D: How much do I need?

How much vitamin D do I need?

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Answer

This is a good question without a simple answer.

It has long been known that vitamin D is crucial for healthy bones. Some research also suggests that vitamin D may play a role in preventing certain cancers and autoimmune diseases.

The National Academies of Sciences currently recommends 200 international units (IU) of vitamin D a day for children and adults up to age 50 and 400 to 600 IU for adults older than age 50. However, researchers now question whether these levels are adequate and assert that a daily intake of 800 to 1,000 IU would benefit many people. In fact, the American Academy of Pediatrics now recommends 400 IU a day for children, beginning the first few days after birth.

Those at highest risk of vitamin D deficiency include:

• Babies who are exclusively breast-fed
• Older adults
• People who have limited sun exposure
• People who have darker skin
• People who have difficulty absorbing fat, as may occur with celiac disease, Crohn's disease, pancreatic insufficiency, liver disease or cystic fibrosis

Many foods contain vitamin D, including fortified milk. Sunlight is also a major source of vitamin D. If you're concerned that you're not getting enough vitamin D, contact your doctor. Ask whether a vitamin D supplement would be appropriate for you.

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