Living in London leaves me with very little exposure to sunshine during the fall/ winter months and I know how important Vitamin D is for our body, (The prevention of chronic diseases, the protection and lubrication of your bones, teeth and hair, the regulation of cellular growth and healthy cell activity, overall reduction of systemic redness and swelling, skeletal health, and postmenopausal women).   The serum helps  support’s  bone, breast, prostate, cardiovascular, colon and immune health.  Also you can find the Vitamin D  fish, eggs, mushrooms, sardines, oats, mackerel.    I take about 6-7 Drops a day for the maximum benefits and also try to get as much sunshine as I can.