Vitamin D -- a hormone workhorse for your health

By Michael Roizen, M.D. and Mehmet Oz, M.D. on May 2, 2024

Vitamin D is an interesting vitamin since it's actually a hormone. It's mostly produced by exposure of your skin to sunlight -- about 10% of your body's active vitamin D comes from foods you eat. When your body produces vitamin D from the sun and absorbs it from food, the liver and kidneys convert it into the hormone calcitriol.

In your body, activated vitamin D helps increase the absorption of calcium, so it can enter your bloodstream, helps prevent calcium loss from the kidneys and promotes the formation of new bone cells. It also plays an important role in bolstering your immune system, pushing calories into muscle rather than fat, countering depression and heart disease and, yes, helping prevent the progression of prediabetes to full-blown Type 2 diabetes.

A 14-year Chinese study shows that folks with prediabetes (almost 100 million Americans) and lower blood levels of vitamin D were far more likely to progress to Type 2 diabetes than those with healthy levels of D -- and if their triglyceride levels were also elevated, the risk was even greater.

Because of how much time most folks spend indoors, we recommend that you get a blood test to check your D levels and take a daily supplement of 1,000 IU of D3 (or more if the test indicates that). You can also boost your D with D-licious wild-caught salmon -- and other foods discussed in the iHerb.com blog, "Which Foods are High in Vitamin D?" And you know where the best recipes are: Dr. Mike's "What to Eat When Cookbook"!

Dr. Mike Roizen is the founder of www.longevityplaybook.com, and Dr. Mehmet Oz is global advisor to www.iHerb.com, the world's leading online health store. Roizen and Oz are chief wellness officer emeritus at Cleveland Clinic and professor emeritus at Columbia University, respectively. Together they have written 11 New York Times bestsellers (four No. 1's).

Distributed by King Features Syndicate, Inc.