Have you ever felt fatigued, drowsy, or depressed during winter?

It could be a sign of Seasonal Affective Disorder (SAD)—a wintertime condition linked to vitamin D deficiency. SAD is associated with a wide range of depressive symptoms such as a depressed mood, lack of interest in normal activities, feelings of worthlessness, disturbed sleep, fatigue, and a decreased ability to think, concentrate or make decisions.

In a recent meta-analysis of 14 studies involving 31,424 people, Stewart et al concluded that low vitamin D levels were associated with an occurrence of depressive symptoms. Specifically, the mechanisms for seasonal affective disorder include:

• Vitamin D levels fluctuate in the body seasonally in direct relation to available sunlight.

• Vitamin D levels in the central nervous system affect the production of both serotonin and dopamine.

• Vitamin D and its responsive elements are found throughout the mid-brain regions, specifically in the hypothalamus, a region that regulates most neural activity.1

It is clear vitamin D deficiency during winter is the main contributor of SAD, but how can we cope without regular access to sunlight? The following recommended vitamin D-boosting strategies for winter can provide some support:

• Go outdoors as much as possible when the sun is out

• Use full spectrum light bulbs or light-boxes (blue light therapy).

• Exercise, go to bed early, get at least 7 hours of sleep each night, or use medication to treat insomnia.

• Avoid processed foods.

• Avoid toxic -cancer causing ingredient sunscreens

• Increase intake of high-quality, animal-based omega three fats.

Most importantly, supplement with vitamin D3 products.

To minimize the amount of necessary oral vitamin D, take vitamin K2 and magnesium along with it. Maintaining some form of healthy fat diet will also help improve vitamin D absorption. Avoid vitamin D2 because it will cause more harm than good.2 Furthermore, you would want to get your vitamin D level tested before you start taking supplement vitamin D. For this test, you are shooting for an ideal level of between 50–70 ng/ml.

For a good supplementation, we recommend a high quality, professional grade vitamin D product.