Take 4 Omega 3 fish oil supplements, daily: (certified free of mercury) it is best if consumed with an antioxidant, such as an orange, or its FRESHLY SQUEEZED juice. If vitamin E is added, it should be certified as being 100% from natural sources, or it may be synthetic: avoid it. In the winter months, if not getting sufficient daily exposure to strong light, see http://www.mercola.com/ SEARCHBAR: enter: "vitamin D3", & Go to a doctor and ask for a 25(OH)D, also called 25-hydroxyvitamin D, blood test. When you get the results, don’t follow the typical “normal” reference range, as these are too low. The OPTIMAL value that you’re looking for is 45-52 ng/ml (115-128 nmol/l)". The company which tests your levels has to be one of those using the correct form of test, and this topic is addressed via the searchbar at www.mercola.com - "vitamin D3; testing".