MEN1 and multiple endocrine neoplasia type 1: Even if MEN1 PHPT is usually milder than the sporadic counterpart and can have an indolent course for years, a non-adequately treated MEN1 PHPT may be associated with hypercalcemia, and lead to prolonged hypercalciuria, increased renal excretion of phosphates, and probable hypo-magnesia, due to increased renal excretion of magnesium.