PTH and Hypocalcemia: Although dietary intake of calcium was typically low, and hypocalcaemia can drive conversion of 25-OHD to active 1,25-(OH)2D via parathyroid hormone (PTH), a raised ALP would be expected in response to elevated PTH and an increase in 1,25-(OH)2D. Higher levels of 24, 25-hydroxylase (which degrades both 25-OHD and 1,25-(OH)2D) are reported in South Asians [12], which is another possible mechanism for reduced 25-OHD levels in this group.