Vit D is synthesised in the body in response to sun exposure or it can be obtained from food/supplement form. Chances are though your not getting enough sun exposure to create optimum amounts of Vit D (especially if you live in the uk). So it might be worth investing in a supplement. Look for 'vitamin D3' as its superior to its standard vitamin D counterpart. For a long time vitamin D was simply looked at as a bone health vitamin, but studies have shown its benefits branch out more. Much, much more....
Lean body mass
Blood sugar regulation
Male and female reproductive health
Prevention of obesity
Treatment of hypertension (high blood pressure)
Bone strength and density
Acts as an anti-depressant
Remember, there's 3 ways you can get your vitamin D levels up
2. Vitamin D3 supplement
3. Eat foods high in Vit D such as cod liver oil, fish, oysters, caviar, eggs, mushrooms.
Hands down, there's no other vitamin or supplement that gives you more 'bang for your buck' than what vitamin D does. It's not only essential for your health and fitness goals, but essential for life!