Vitamin D is a fat-soluble nutrient needed to absorb calcium and phosphorus, and therefore to make bones strong. People do not make their own: We need sunlight to synthesize vitamin D. The vitamin also is found in oily fish and in a few other foods, including milk, which is fortified with the vitamin. Only recently has there been an ‘epidemic’ of people with low Vitamin D levels. Is it real? Click here for more information