Vitamin D for Seasonal Affective Disorder

Vitamin D is no longer considered a vitamin, but a “pro-hormone”. Exciting research about vitamin D is on the horizon, and some evidence supports a link to depression, although some studies do not support this link. Just about every patient I have ever checked in Seattle has been vitamin D deficient. Vitamin D is produced in our bodies when UV light touches our skin.

Most people living in the northern latitudes are easily vitamin D deficient if they do not spend 20 minutes outside each day. Elderly people have thinner skin, and thus produce less vitamin D, they also absorb less dietarily. Until further evidence supports this theory linking depression with low vitamin D levels, it only makes sense to be sure that you are at least not deficient in vitamin D. The RDA for adults ranges between 200 IU and 600 IU.

Food sources of vitamin D are milk, fish, and yeast. I typically recommend 1000 IU of vitamin D for my patients struggling with depression as a cheap and easy insurance policy that they are not deficient in vitamin D. If you would like to have your levels checked be sure that your physician orders the “25-OH-D” as that is the most reliable indicator of vitamin D stores. Do not ever exceed 1000 IU of vitamin D unless under the care of your naturopathic physician. Dangerous side effects such as hypercalcemia can occur.

As we continue to do more research, vitamin D may in fact be the "magic bullet" (pictured) for seasonal depression help.