According to findings published in the Journal of Affective Disorders, analysis of blood levels of vitamin D, in the form of 25-hydroxy-vitamin D (25(OH)D), of more than 3,000 people highlighted no clear links between depressive symptoms and 25(OH)D levels.
Vitamin D deficiency exists when the concentration of 25-hydroxy-vitamin D (25-OH-D) in the blood serum occurs at 12ng/ml (nanograms/millilitre) or less. The normal concentration of 25-hydroxy-vitamin D in the blood serum is 25-50ng/ml.
“Few studies have explored the association between blood 25-hydroxyvitamin D concentrations and depression in the general population. A deficiency of vitamin D has also been attributed to several chronic diseases, including osteoporosis, common cancers, autoimmune and cardiovascular diseases,” said lead author Dr Oscar Franco from Warwick Medical School.
"Previous studies into the effects of vitamin D supplementation have produced mixed results. More studies are still needed to evaluate whether vitamin D is associated with seasonal affective disorders, but our study does raise questions about the effects of taking more vitamin D to combat depressive symptoms,” he added.