We’ve talked at length about the importance of sleep hygiene—the sleep-wake cycle, diet and exercise—but also of critical importance is the “sunshine vitamin,” the hormone we call “Vitamin D.” Readers of the BOOK- "It's not Mental"
Historically, the FDA made a grave error in its vitamin D recommendation level due to a misunderstanding in the scientific community about what vitamin D does. Their recommendation was just high enough to prevent immediate damage (rickets) and immediate death but, at the time, they did not realize that this did not prevent slower long-term damage (“mental” illness, autoimmune diseases, lower immune function, obesity) and earlier deaths (cancer, heart attacks).