Effect of adding potassium bicarbonate or sodium bicarbonate on high protein induced hypercalciuria
Date
1993-08
Authors
Green, Timothy John
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
0000-0002-0667-4300
Type
Degree Level
Masters
Abstract
Alkaline potassium salts such as potassium bicarbonate
and potassium citrate have been reported to reduce urinary
calcium excretion when administered to subjects consuming
moderate protein diets. Sodium bicarbonate administration
has been reported to reduce the hypercalciuria induced by a
high protein diet. Studies of subjects consuming a moderate
protein diet, however, have failed to show a hypocalciuric
effect of sodium bicarbonate. Due to the contradictory
findings of the effects of sodium bicarbonate on urinary
calcium excretion, one of the objectives of the present
study was to clarify the effect of sodium bicarbonate on
high protein- induced hypercalciuria. The second objective
was to establish the effect of potassium bicarbonate on high
protein induced hypercalciuria.
The study was divided into five experimental weeks for
a total length of 33 days. Eight healthy males were fed a
moderate protein (MP) diet and, randomly, each of the
following supplements for four day periods: 60 g protein
(HP), 60 g protein + 90 mmol sodium bicarbonate (HP+Na), and
60 g protein + 90 mmol potassium bicarbonate (HP+K). Diets
were similar in energy, calcium, and phosphorus. Subjects
provided a 24-hour urine sample on Day 3 and Day 4 and a
fasting urine and blood sample on Day 5 of each experimental
week.
As expected, both Day 3 and Day 4 urinary calcium
excretion were significantly increased during the HP
treatment relative to the MP treatment, by 58% and 40%
respectively. On Day 3, adding sodium bicarbonate to the
HP treatment reduced urinary calcium excretion by 25%. This
hypocalciuric effect of sodium bicarbonate disappeared on
Day 4. With the addition of potassium bicarbonate, both Day
3 and Day 4 urinary calcium excretion was reduced relative
to the HP treatment by 39% and 47% respectively. The
addition of potassium bicarbonate reduced urinary calcium
excretion to the level of the MP treatment. On both Day 3
and Day 4, net acid excretion (NAE) was significantly higher
during the HP treatment relative to the MP treatment. The
addition of bicarbonate as either potassium bicarbonate or
sodium bicarbonate resulted in significantly reduced NAE, to
levels below those of either the HP and MP treatments. Day
4 urinary phosphate excretion was reduced during the HP+K
treatment relative to the other three treatments. There
were no significant changes in the levels of serum
calcitriol or in the urinary excretion of hydroxypyridinium
compounds.
This experiment suggests that sodium bicarbonate does
not have a sustained effect on high protein induced
hypercalciuria. A study of longer duration may be
necessary, however, to fully clarify the action of sodium
bicarbonate. In addition, this experiment demonstrated that
potassium bicarbonate reduces high protein induced
hypercalciuria to levels of a moderate protein diet. It may
be suggested that alkaline potassium, found in fresh fruits
and vegetables, may alleviate the hypercalciuria of a North
American diet which is typically high in protein
Description
Keywords
Chemistry, Chemical technology, Hypercalciuria
Citation
Degree
Master of Science (M.Sc.)
Department
Pharmacy and Nutrition
Program
Pharmacy