Millie
You also need magnesium . even when blood levels are normal,tissue stores can be low. magnesium is involved in muscle relaxation. try twice the RDA. best absorbed is magnesium glycinate and magnesium chloride. try 800 mg/day (RDA is 400 mg/day for an average guy). but you need to replenish and unless you have kidney dz you are safe taking this much. malic acid magnesium is the best kind for fibromyalgia if that is what you have.