I was at the doc recently for some routine bloodwork, etc and told her I'd been feeling so tired and crazy lately (horrible mood swings, bouts of rage, etc) and maybe even a bit depressed. After asking me about what's all going on in my life, she attributed a lot of it to stress and situational depression. However, when my blood levels came back I had a significant Vitamin D deficiency. Several references say that for optimum health, levels should be around 50-80 ng/mL. I was at 18.
I was shocked to learn that my doctor among others has started testing for this regularly and finding quite a few folks who have low levels. Who knew?!!
Apparently Vitamin D deficiency can cause all sorts of issues such as severe mood swings, depression, aches and pains, extreme fatigue, etc. I wonder how many cases of CFS or fibromyalgia can be attributed to vitamin deficiency at least in part? If you have any issues with these types of symptoms, I'd suggest having your levels checked as well. It's a simple blood test!
Research has also shown that low D levels can cause increased risk of heart disease, breast cancer, etc.
Researchers at Johns Hopkins are reporting what is believed to be the most conclusive evidence to date that inadequate levels of vitamin D, obtained from milk, fortified cereals and exposure to sunlight, lead to substantially increased risk of death.