I am 51 yo F - Whenever I take magnesium (now so important with my calcium) it never fails...my nails whiten (diff places) and get so sore at these spots. If I continue on mag they will loosen and come off. I have searched a solution for yrs. Doctors say not fungus. It only happens if I take mag in some type. Foods containing mag do not cause the level of damage nor soreness. Am I not absorbing mag? I take with and without cal, with C, and with food...