@xinamatusx - I'm afraid your questions about calcium and magnesium and potassium are beyond my experience. I don't know if you could have low intracellular calcium but normal blood levels. However, I bet someone here might have some answers or at least suggestions. I'd suggest a new thread with the title asking specifically about the interrelationship between these electrolytes, or about serum calcium vs. intracellular calcium. Wish I could help!