Vitamin D is necessary for proper calcium utilization. Many people with CFS/fibromyalgia do better on a somewhat higher sodium intake(don't overdo it though). Many women are iron deficient. Musles contain myoglobin which contains iron. Iron is also needed for making hemoglobin. Iron bisglycinate is a well absorbed form that doesn't cause digestive side effects. Take it with vitamin c for better absobtion.

I was eating many natural foods and sudenly realized that my sodium intake was under 500 mg a day. It should be 2,000-3,000 mg a day. I need to remember to add salt to my food. Plenty of odium is in all processed foods, but not much is in in most natural foods.