This is the “winter blues”, the common name of a syndrome that conventional medicine define, very appropriately as SAD (Seasonal Affective Disorder), or the less attractive name of “Winter Depression”.
As for many of today's health problems the specific causes of SAD are unknown, but amongst the factors that are considered to contribute, are reduced levels of sunlight exposure, together with age and genetics predisposition.
The reduction of sunlight we are exposed to negatively impacts on the production of serotonin and melatonin, some of the hormones that control sleep and awakening and the coordination of these two functions. Because serotonin and melatonin are deeply involved in mood control, susceptible people can experience anything from dark moods to full-blown depression.
But another factor involved in SAD is vitamin D. Vitamin D is produced in the skin after sun exposure (in most people), and is implicated in many fundamental activities in the body, some of which affect the brain. Supplementation with Vitamin D has been found in different studies to be effective in improving mood and increasing general well being in people affected by SAD.
SAD is medically treated with conventional antidepressants, but if you are feeling excessively moody in the cold season it is always a good idea to increase your sun exposure.
The sunlight will not only stimulate vitamin D production but will trigger a gentle rebalance of the “mood hormones” that will help to decrease the intensity of the SAD symptoms (light therapy).
For people prone to SAD open air activities are recommended throughout the year to replenish your vitamin D storage, especially if you are a female, live far from the equator and have a family history or suffer from depression. Getting physically active in open air, by simply walking at fast pace for 30-40 min/day, has been demonstrated to have a positive effects also on digestion, bowel function and cardiovascular health, as well as being mood elevating.
Good food can help sustaining Vitamin D, that is particularly abundant in the oils of cold water fish (cod especially liver, salmon, mackerel, herring, sardine, trout, tuna), oysters and crustaceans, soy products (soy milk, tofu), full milk, mushrooms, beef, veal and eggs.
Through proactive techniques such as light therapy, physical activity and good nutritional choices you can decrease the effects of SAD altogether each season.