Abstract
Sodi et al. 1 address an important practical issue for laboratories: whether acidification of urine is necessary for accurate urine calcium measurements. They have shown that addition of acid after collection to a 24-h urine collection is not required to stabilize the calcium concentration. They have not shown that acid is unnecessary during the collection. It is possible (at least in theory) that calcium is lost from solution in unacidified urine during the collection period and that this calcium is not returned to solution by subsequent acidification. To address this question requires a comparison between urines that have and have not been acidified immediately after voiding.
DECLARATIONS