In the Summer months, most people experience a jaunty improvement in their mood and a more positive outlook on life. But are there other less obvious benefits than achieving an even tan and beautiful sun-streaked hair? According to researchers at the University of California, the answer may be a resounding yes.

The UVB fraction of visible light that comes from the sun reacts with melanin, a pigment in the skin, to produce vitamin D. In the Summer months, since the period of light is lengthened and the light is more intense, vitamin D levels are boosted. There is already a well documented link between higher levels of Vitamin D and improved mood, and the benefit of vitamin D on enhancing immune function is also well described. Activated vitamin D, a steroid hormone, stimulates anti-microbial immunity, especially innate immune defenses. Studies have now shown a link between higher vitamin D levels and improved immunological control of two serious pathogens, Mycobacterium tuberculosis (M.tb), the causative agent of tuberculosis, and human immunodeficiency virus (HIV) in human patients. Vitamin D supplementation is now a serious contender to be added to the arsenal of treatments available for these diseases.

Vitamin D is not only generated from exposure to sunlight, it can also be obtained through dietary means: butter, eggs and cod liver oil are all natural sources. Consider keeping these things in your diet over Winter to naturally boost your mood.

Campbell GR, & Spector SA (2012). Vitamin D inhibits human immunodeficiency virus type 1 and Mycobacterium tuberculosis infection in macrophages through the induction of autophagy. PLoS pathogens, 8 (5) PMID: 22589721