Depression is increasingly common in the Western nations., This may relate to the mentally stressful lives these populations live. Depression can be severely debilitating to the sufferer, and research shows that in many cases depression is a chronic disorder that often has no obvious single cause. The role of poor nutrition is well established and there is good evidence that healthy eating can improve mood scores. Vitamin D has been researched with regard to its role in the development and treatment of depression and a number of studies have shown associations between poor vitamin D status and depressive symptoms. This is of particular interest as evidence from large scale nutrition surveys suggest that a large proportion of those living in the developed nations are deficient in vitamin D. The elderly are at particular risk of poor vitamin D status. A number of studies have shown an association between poor vitamin D status and depression, although it is not known if the vitamin D status is the causal factor.
The higher rates of schizophrenia amongst those born in the winter and spring months, and the higher rates of developing schizophrenia in dark skinned migrants to temperate climates compared to native inhabitants suggest a role for vitamin D in other mental illnesses. In Finland, supplementation with vitamin D during the first year of life was associated with a significant reduction in the rates of schizophrenia in males. The neuroprotective effects of vitamin D may be particularly important during periods of brain development. The association between dementia and vitamin D deficiency also may reflect this neuroprotective effect of vitamin D in humans.
Further, it is known that depressive symptoms often vary depending on the season. As vitamin D levels drop in the winter, the severity and prevalence of depressive symptoms increases, suggesting a possible causal association. In one study, subjects with seasonal affected disorder, a syndrome of depression associated with the winter months, were shown to have significant reductions in their depressive symptoms by administration of 100,000 IU vitamin D. Other studies have not found improvements in depressive symptoms with administration of vitamin D, but many studies have used much smaller doses. For example, one study that found no effect only used 800 IU of vitamin D per day. Vitamin D receptors are widely distributed in the eye and brain of humans, and this suggest that seasonal production of vitamin D may affect seasonal behaviour. Further, vitamin D may play a significant role in neuroprotection and the implication is that low levels of vitamin D may cause detrimental structural changes in the brain.
Eat Well, Stay Healthy, Protect Yourself
RdB
