The primary source of Vitamin D for both children and adult is from sun exposure. Vitamin D is naturally produced in the skin following exposure to sunlight.
In contrast, very few foods naturally contain vitamin D (namely fatty fish, egg yolks and liver) or are fortified with vitamin D. As a result, a varying percentage of people are vitamin D deficient at any time, with this percentage being higher in the winter, among elderly or obese, in sun-deprived individuals and in dark skinned people .
In the body, vitamin D is responsible for maintaining normal blood levels of calcium and phosphorus and for supporting bones health. Vitamin D works with other vitamins, minerals and hormones to promote bone mineralisation. Additionally, research shows that vitamin D may help support a healthy immune system.