ADGRL3 and vitamin D deficiency: We were unable to detect differences between null and WT mice (mean [SEM]: null = 135.5 [3.9] mmol/L, WT = 135.8 [4.4] mmol/L; t (15) = 0.07, P = 0.95), indicating that vitamin D deficiency is an unlikely cause of the low serum calcium levels in the Lphn3 null mice.