Vitamin D
After Vitamin D has been synthesized (this is the skin's response to sunlight), in the kidneys/liver it is converted to its active form. Active vitamin D regulates Ca2+ metabolism. In the gut, Vitamin D encourages Ca2+ uptake and simulatenously reducing the amount of reducing the excretion of Ca2+ in the kidneys [1].
Vitamin D is one of many very important vitamins that our bodies need to stay fit and healthy. Most people don't even realise or know that we gain the majority of vitamin D from direct sunlight on our skin. However, it is also found in some foods and a combination of a good diet and enough time out in the sun and our bodies will recieve enough to function at a healthy and normal level.
Vitamin D is required to mainly help regulate calcium levels within the body and therefore bone health.[2] As more research is undergone we are starting to believe 'vitamin D deficiencies may be linked to various cancers' as is written about in Nature Reviews Cancer 7, 684-700 (September 2007) by Kristin K et al.