Here’s a list of studies about vitamin D and depression:
Serum 25-Hydroxyvitamin D Concentrations and Depressive Symptoms Among Young Adult Men and Women (2014)
Conclusion: A study of 615 young adults found that those with lower vitamin D levels had worse depression scores.
Suicidal Patients are Deficient in Vitamin D, Associated with a Pro-Inflammatory Status in the Blood (2014)
Conclusion: 59 suicide attempters were enrolled in a study and tested for their vitamin D status along with non-suicidal depressed people and non-depressed healthy control subjects. 58% of the suicide attempters were clinically deficient in vitamin D and had lower levels than than the non-suicidal depressed subjects and non-depressed, healthy control subjects.
Depression is Associated with Decreased 25-Hydroxyvitamin D and Increased Parathyroid Hormone Levels in Older Adults (2008)
Conclusion: A study of 1,282 Dutch elderly people found that those who reported having minor and major depression had lower vitamin D levels compared to the rest of the participants.
Vitamin D Deficiency is Associated with Low Mood and Worse Cognitive Performance in Older Adults (2006)
Conclusion: A study of 80 older adults found that 58% had inadequate vitamin D levels and those with lower levels had worse scores on depression and cognitive function tests.
Neuropsychological Function in Relation to Serum Parathyroid Hormone and Serum 25-Hydroxyvitamin D Levels. The Tromsø Study. (2006)
Conclusion: This study of 21 patients suffering from secondary hyperparathyroidism found that they had lower vitamin D levels compared to 63 control subjects. Those with lower vitamin D levels also had a higher depression score.
Conclusion: A study of 101 healthy men found that their serotonin levels were lowest during winter, when there’s less sunlight, but “rose rapidly” as the amount of bright sunlight increased.
Conclusion: Bright light treatment was found to alleviate depression faster than medication. (You know… like SUNLIGHT)
Conclusion: Morning bright light therapy is more effective as an antidepressant compared to evening bright light therapy. (Yep, the sun rises in the morning.)
Conclusion: Compared to normal women, depressed women tend to have lower bone mineral density. Both depression and lower bone mineral density are symptoms of vitamin D deficiency.