If you're running low on Vitamin D, new research indicates you may also experience depression.
The very small study suggests that vitamin D deficiency and depression may travel together, and that filling up the "vitamin D tank" may help relieve some of the symptoms.
Vitamin D levels below 21 nanograms per milliliter of blood are considered vitamin D deficient. Normal vitamin D levels are above 30 ng/mL, according to guidelines set by The Endocrine Society.
Experts say, there's no solid proof that vitamin D deficiency causes depression.