Scientists from Finland reporting in this month's issue of the European Journal of Clinical Nutrition found that vitamins B6, B12 and D, as well as the mineral calcium, raised folate levels and cut the homocysteine concentration in people subjects without folate deficiency.
After a two-week run-in period, 60 subjects in eastern Finland drank either water containing folic acid (563 mcg/d), calcium (563 mg/d) and vitamins B6 (1 mg/d), B12 (7.5 mcg/d) and D (0.6 mcg/d), or placebo.
After eight weeks of supplementation, plasma homocysteine levels decreased by 1.6 micromol/L and serum folate concentration increased by an average of 16.1 nmol/L in subjects consuming the fortified water. The researchers from the University of Kuopio in Finland also noted the calcium used in the fortified water was bioavailable, based on individuals' calcium levels and bone metabolism.
Full findings are published in the 'European Journal of Clinical Nutrition (2004) 58, 376-385.
In a separate study published this month, scientists at the University of Bonn in Germany set out to evaluate the effect of a mineral water rich in magnesium (337 mg/l), calcium (232 mg/l) and bicarbonate (3388 mg/l) on urine composition and the risk of calcium oxalate crystallization.
They carried out a small study of 12 healthy male volunteers who consumed 1.4 l/day of a neutral fruit tea, which was replaced by an equal volume of a mineral water during the test phase. On the follow-up phase, subjects continued to drink 1.4 l/day of the mineral water on their usual diet and collected 24 hour urine samples weekly.
The researchers report that during the intake of mineral water, urinary pH, magnesium and citrate excretion increased significantly on both standardized and normal dietary conditions.
'The mineral water led to a significant increase in urinary calcium excretion only on the standardized diet, and to a significantly higher urinary volume and decreased supersaturation with calcium oxalate only on the usual diet,' write the scientists.
They conclude that magnesium and bicarbonate content of the mineral water resulted in 'favorable changes in urinary pH, magnesium and citrate excretion, inhibitors of calcium oxalate stone formation, counterbalancing increased calcium excretion'. But they warn that since urinary oxalate excretion did not diminish, further studies are necessary to evaluate whether the ingestion of calcium-rich mineral water with, rather than between, meals may complex oxalate in the gut and thereby limiting intestinal absorption and urinary excretion of calcium and oxalate.
Full findings are published in the February 2004 issue of the European Journal of Clinical Nutrition (2004) 58, 270-276.