Winter is here in the northern hemisphere. Until the winter solstice (December 21st), every day will have less sunlight and more darkness than the day before.
In the winter, at many latitudes, all the UV that is present is UVA wavelength, not UVB. Remember, UVB are the rays responsible for your body making vitamin D. So in the winter, it’s impossible to make much vitamin D if you’re living north of about 35 degrees latitude (and still not much between 30 and 35).
Despite this shortcoming in wintertime sun exposure, evidence has been presented that UV light does more than just make vitamin D. For example, it was UV light in general, and not 25(OH)D levels, that improved quality of life indicators in a recent study.
In 2012, Brant Cebulla wrote a good blog summing up what good UV light does outside of vitamin D production.
So I still seek sun exposure in the wintertime, even without the UVB. While I continue to get UVA in the winter from sunshine, I keep a UVB light in my office for the winter as I think both moderate amounts of UVA and UVB light are important for health.
One option is to go to sun tanning parlors and ask for old-fashioned low-pressure UV sunbed. They approximate the wavelengths in sunlight.
However, if readers want a device for their own home and want to buy a UV light with UVB for home use (one that allows you to make vitamin D), you have several choices.
One choice is Sperti’s FDA approved vitamin D lamp:
The Vitamin D Council approves this manufacturer. However, UVB lights can burn the skin, so be careful to follow the manufacturers’ recommendations.