Post-partum Hypercalcaemia in Treated Hypoparathyroidism

Two patients with post-thyroidectomy hypoparathyroidism were observed throughout three pregnancies. Their normal maintenance treatment with vitamin D remained unaltered. Serum calcium levels remained normal until shortly before delivery but rose rapidly in the immediate postpartum period to peak levels of 7·8, 6·0, and 6·8 mEq/l. while still on normal or reduced maintenance treatment. This apparent increased sensitivity to vitamin D after delivery persisted for as long as three months.