title: Effects of bicarbonate supplementation on urinary mineral excretion during very low energy diets.
abstract: Metabolic acidosis is associated with increased calciuria and ammoniagenesis. This study evaluated the effects of oral sodium bicarbonate (NaHCO3) or combined potassium bicarbonate-calcium carbonate supplementation on urinary mineral excretion during the ketoacidosis of a very-low-energy protein diet. Seventeen healthy obese subjects (BMI: 37.5 +/- 3.2 kg/m2, weight: 100 +/- 3 kg) were given a 1.72 MJ all protein (93 g) liquid formula and a multivitamin-mineral supplement daily for 3 weeks. Subjects in groups 1 (n = 6) and 2 (n = 5) received 16 mmol KCl. In addition, subjects in group 1 received 60 mmol Na+ daily as sodium chloride, subjects in group 2, 60 mmol Na+ as NaHCO3. The subjects in group 3 (n = 6) were given 32 mmol K+ as bicarbonate and 16 mmol Ca++ as carbonate daily. Metabolic acidosis was prevented in groups 2 and 3 with bicarbonate and bicarbonate-carbonate administration. This was reflected in significant curtailment of the augmented ammonium nitrogen excretion found in group 1. The additional oral K+ in group 3 improved K+ balance and probably also inhibited ammoniagenesis. Urine calcium was greater (p less than 0.04) in group 1 subjects, but similar in groups 2 and 3, despite higher calcium intake in group 3. Urinary phosphorus decreased with time in all groups, but more so in the group 2 subjects who received NaHCO3. Acidosis was associated with the reverse effect on urinary magnesium, which decreased in group 1 subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: McGill Nutrition and Food Science Centre, Royal Victoria Hospital, Montreal, Quebec, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Gougeon-Reyburn
authors.forename: F
authors.initials: F
authors.lastname: Larivière
authors.forename: E B
authors.initials: EB
authors.lastname: Marliss
mesh_terms: D000138:Acidosis / Q000628:therapy; D000641:Ammonia / Q000652:urine; D001639:Bicarbonates / Q000627:therapeutic use*; D002118:Calcium / Q000378:metabolism; D004038:Diet, Reducing; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000378:metabolism; D008297:Male; D008903:Minerals / Q000652:urine*; D009765:Obesity / Q000628:therapy / Q000652:urine; D010758:Phosphorus / Q000378:metabolism; D011188:Potassium / Q000378:metabolism
chemical_list: D001639:Bicarbonates; D008903:Minerals; D010758:Phosphorus; D000641:Ammonia; D008274:Magnesium; D011188:Potassium; D002118:Calcium