Formula fed twin infants with recurrent hypocalcemic seizures with vitamin D deficient rickets and hyperphosphatemia.

Vitamin D deficient rickets is generally known to occur in breast fed infants. And excessive phosphate ingestion is a main cause of late onset hypocalcemia in formula fed infants. Here we introduce 45-day-old formula fed hypocalcemic twins with recurrent seizure attacks. They were diagnosed as having both of vitamin D deficient rickets and hyperphosphatemia. Radiologic findings indicated mild rickets and the twins were treated with calcium and alfacalcidol. After 3-5 months of oral supplementation, medication was discontinued in both twins. They showed normal growth and calcium, phosphorus, and vitamin D levels during the 6-month follow-up period. Twins can be at risk for hypocalcemia because of their high risk of vitamin D deficiency, low birth weight, and premature birth. Therefore twin pregnant women need ingestion of sufficient vitamin D and calcium.