Vitamin D Doesnt Shine Light on SAD

COVENTRY, United Kingdom— A lack of vitamin D, due to reduced sunlight, has been linked to depression and the symptoms of Seasonal Affective Disorder (SAD), but research by the University of Warwick reveals no clear link between the levels of vitamin D in the blood and depression.

For the study, published in the Journal of Affective Disorders, the team recruited more than 3,000 people and tested levels of vitamin D (25-hydroxyvitamin D) in the blood. They carried out a questionnaire with the participants to assess the prevalence of depressive symptoms.

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. Researchers found no clear association between depressive symptoms and the concentration of vitamin D in the blood.

Oscar Franco, MD, lead researcher and assistant clinical professor in Public Health, said: “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.”