Tetany of Vitamin D Deficiency (infantile tetany) Accompaning rickets Serum ionized calcium concentration falls below 3-4mg/dl Muscular irritability Diagnosis based on the combined presence of rickets. low serum calcium concentration. and symptoms of tetanyTetany of Vitamin D Deficiency (infantile tetany) ➢ Accompaning rickets ➢ Serum ionized calcium concentration falls below 3-4mg/dl ➢ Muscular irritability ➢ Diagnosis based on the combined presence of rickets, low serum calcium concentration, and symptoms of tetany