What on earth are we drinking?

During the past few years there has been a considerable increase in the number and variety of still and carbonated bottled drinking waters, which have an enormous variation in calcium content ranging from 0 to over 500 mg/l. Patients with upper urinary tract stones are often advised to maintain a high fluid intake in order to achieve an increased urinary output. If they find tap water unpalatable and drink bottled water instead, they could significantly increase their daily calcium intake by as much as 1.5 g. The majority of bottled waters presently available in this country, together with tap water samples from throughout the British Isles, have been analysed and the results suggest that there are some waters which stone formers should avoid.