Drs. Oz and Roizen: How much vitamin D? IOM right or wrong

Q: I just read that we should be taking 10 times more vitamin D-3 than the current recommendations. Is that true? And can it hurt you to take too much? — Steven F., BostonA: You must be referring to the new study that says the recommended dietary allowance for vitamin D (600 IU per day through age 70; 800 IU per day for those 71 and older) from the National Academy of Sciences/Institute of Medicine is 10 times lower than it should be. Seems NAS/IOM made an error when they developed the standard, so the researchers are calling for a new guideline: 7,000 IU of D-3 daily for all ages. That, they say, is enough to prevent health problems related to vitamin D deficiency.

We can’t tell you to take that dose, because some folks make that much (with sunlight) anyway. And there can be toxicity from too much vitamin D-2 or D-3. But we do know that most people don’t get enough vitamin D-3 to maintain strong bones and a healthy immune system.

What causes D-ficiency?

• Too much indoor time.

• Being overweight: Body fat holds on to D and deprives other cells of the D they need.

• Aging: If you’re over 65, you may have less ability to convert sunlight into D-3.

• A darker skin tone. A light-skinned person in a bathing suit may produce 10,000 to 20,000 IU of D by spending 10-12 minutes in the summer sun. Medium-toned skin takes about 30 minutes to make that much; dark skin can take up to 120 minutes.

Best bet: When you see your doc, get your vitamin D blood level checked and ask if taking a vitamin D-2 or -3 supplements is right for you.

Low levels of D are associated with depression, cognitive decline, osteoporosis, cancer, cardiovascular disease and Type 2 diabetes. And new research has found that taking vitamin D may help keep low-grade prostate cancer from becoming aggressive; when taken with metformin, it may prevent colon cancer; and it can help the body’s immune cells prevent atherosclerosis and diabetes.

What we do: We each take 2,000 IU of vitamin D-2 or -3 every day; make sure to get out into the sun (walking, walking); and eat foods rich in D, such as salmon.

Dr. Mehmet Oz is host of “The Dr. Oz Show,” and Dr. Mike Roizen is Chief Wellness Officer and Chair of Wellness Institute at Cleveland Clinic. Email your health and wellness questions to youdocsdaily@sharecare.com.

In the News

Drs. Oz and Roizen: is the IOM right or wrong?