Hypercalcemia and metastatic calcification.

Abstract

Time for primary review 27 days. I grew up in Edinburgh, at the same latitude as Copenhagen, and then covered by a pall of coal smoke which gave it the sobriquet ‘auld reekie’. Many bandy-legged and dwarfed citizens carried the legacy of rickets contracted before the discovery of vitamin D, the fortification of food and the Clean Air Acts. However vitamin D, good in the right dose, is dangerous in overdose and there is no doubt that Gorm's Vikings miscalculated the dose–response curve of cod liver oil; a teaspoon would have been a better implement than their ladle or Mrs. T's tablespoon. In view of their formidable achievements, it is likely that the Vikings escaped the worst effects of vitamin D intoxication by irregular dosage and non-compliance. Their cavalier approach was repeated with more disastrous results after 1924 when high doses of tasteless ergocalciferol (vitamin D2) from irradiated ergosterol became available and were indiscriminately prescribed for rheumatoid arthritis, tuberculosis, Paget's disease and chilblains, in none of which it has been shown to produce benefit, and osteoporosis. The effects of overdosage were described within four years of high dose ergocalciferol being released for sale; the condition was reviewed in a cluster of papers in the early 1950's [1–3]. Diagnosis was often delayed because the commonest symptoms were the non-specific ones of hypercalcemia — nausea, vomiting, weight loss, colic, constipation, thirst, polyuria, headache, weakness, apathy and depression roughly in that order [1]. Once suspected, the diagnosis was confirmed by the presence of hypercalcemia and renal impairment. Although vitamin D stimulates phosphate absorption, serum phosphate was often normal, as in Mrs. T, unless the renal damage was severe. Reduction of serum calcium by administration of cortisol distinguished this cause of hypercalcemia from hyperparathyroidism; one action of cortisol is to inhibit … * Corresponding author.