Raised parathyroid hormone levels in the milk alkali syndrome: an appropriate response?

A case of the 'milk alkali syndrome' associated with grossly elevated levels of amino terminal parathyroid hormone is described. The hypercalcaemia (calcium 4.09 mmol/l) and hyperparathyroidism settled on conservative measures. Factors in the milk alkali syndrome which might stimulate the release of parathyroid hormone include parathyroid gland hyperplasia secondary to suppression of ionized calcium, alteration in sensitivity of calcium receptors on the cells of the parathyroid glands, the stimulation of an intermittent alkaline tide in the blood and the high intake of phosphate and bicarbonate. We suggest that high levels of parathyroid hormone in the milk alkali syndrome may be appropriate rather than paradoxical.