Assuming that the diagnosis of APS-1 and hypoparathyroidism are correct, high doses of activated vitamin D (Rocaltrol or Calcitrol 1-3 mcg daily) plus at least 2,000mg oral calcium daily usually control this. If there is a lot of malabsorption going on, fat restriction is a useful thing to do. The magnesium level should be checked if the problem continues also as low levels of magnesium can affect the calcium level adversely. If diarrhea is a problem, consider metroniadazole course to cover invasive giardia. Further IgA levels should be checked as well as antibodies against tissue tranglutaminase to exclude underlying celiac disease or IgA deficiency.
Kind regards,
Noel K Maclaren MD