Vitamin D Supplements

Is it necessary to take vitamin D supplements? Vitamin D, which is made mostly by animals, including ourselves, when we’re exposed to sunlight, may help us enjoy a longer life based on randomized, controlled studies. It’s also been shown to improve pain from menstrual periods and help prevent respiratory infections.

If you don’t get adequate sun exposure, I recommend 2,000 IU vitamin D supplements daily, ideally with the largest meal of the day.

Mushrooms, interestingly, also make vitamin D when exposed to sunlight radiation, but most mushrooms found in the produce section of our local markets don’t have any vitamin D because they’re grown in the dark. I also don’t recommend tanning beds because they can be both ineffective and dangerous. (The lamps emit mostly UVA, which increases melanoma skin cancer risk while producing less vitamin D.)

Note that the longevity effects appeared limited to vitamin D3, though, the type derived from plants and animals—not vitamin D2, the type derived from yeast and mushrooms.

For an overview, see Dr. Greger’s Vitamin D Recommendations infographic.

The information on this page has been compiled from Dr. Greger’s research. Sources for each video listed can be found by going to the video’s page and clicking on the Sources Cited tab. References may also be found at the back of his books.