The independent Vitamin D Council suggests that people should use a sunbed in the winter — being careful to avoid a sunburn — as one of the primary ways to make sufficient vitamin D.

Dr. John Cannell, founder of The Vitamin D Council, lists three ways for adults to ensure adequate levels of vitamin D on the Council’s web site.

1. Regularly receive midday sun exposure in the late spring, summer, and early fall, exposing as much of the skin as possible for 20–30 minutes (being careful to never burn). The Council points out that those with dark skin will need longer exposure time — up to six times longer.
2. Regularly use a sunbed (avoiding sunburn) during the colder months.
3. Take 5,000 IU per day for 2–3 months, then obtain a 25-hydroxyvitamin D test. Adjust your dosage so that blood levels are between 50–80 ng/mL (or 125–200 nM/L) year-round.

The Vitamin D Council points out that vitamin D is not a vitamin — it’s a precursor to a hormone intended to be made naturally in the skin. That’s why it’s called “the sunshine vitamin.”

“Humans make thousands of units of vitamin D within minutes of whole body exposure to sunlight,” Cannell says. “From what we know of nature, it is unlikely such a system evolved by chance.”