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ARS Home » Northeast Area » Boston, Massachusetts » Jean Mayer Human Nutrition Research Center On Aging » Research » Publications at this Location » Publication #230181
Title: Treatment with Potassium Bicarbonate Lowers Calcium Excretion and Bone Resorption in Older Men and Women

Author
item Dawson-Hughes, Bess
item HARRIS, SUSAN - JM USDA HNRCA @ TUFTS
item PALERMO, NANCY - JM USDA HNRCA @ TUFTS
item CASTANEDA SCEPPA, CARMEN - NORTHEASTERN UNIVERSITY
item RASMUSSEN, HELEN - JM USDA HNRCA @ TUFTS
item Dallal, Gerald

Submitted to: Journal of Clinical Endocrinology and Metabolism
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/10/2008
Publication Date: 1/1/2009
Citation: Dawson-Hughes, B., Harris, S.S., Palermo, N., Castaneda Sceppa, C., Rasmussen, H.M., Dallal, G. 2009. Treatment with Potassium Bicarbonate Lowers Calcium Excretion and Bone Resorption in Older Men and Women. Journal of Clinical Endocrinology and Metabolism. 94:96-102.

Interpretive Summary: There is increasing evidence that a mild acid state may have adverse effects on bone health in humans. Fruits and vegetables are metabolized to alkaline compounds whereas protein and cereal grains are metabolized to acidic compounds. On average, American diets tend to be acid-producing and after age 50, men and women have a gradually increasing acidosis as they age. This study was conducted to determine whether increasing intake of alkali by taking bicarbonate supplements would reduce calcium losses in the urine and the rate of bone resorption, both indicators of bone loss. We conducted a 3-month randomized, placebo-controlled trial was conducted in 171 healthy men and women age 50 and older we treated with either bicarbonate or no bicarbonate. Supplementation with bicarbonate significantly lowered the excretion of calcium and of the biochemical marker of bone resorption, N-telopeptide. These findings are consistent with bicarbonate reducing the rate of bone loss, but further study is needed to demonstrate this.

Technical Abstract: Bicarbonate has been implicated in bone health in older subjects on acid-producing diets in short-term studies. The objective of this study was to determine the effects of potassium bicarbonate and its components on changes in bone resorption and calcium excretion over 3 months in older men and women. In this double-blind, controlled trial, 171 men and women age 50 and older were randomized to receive placebo or 67.5 mmol/d of: potassium bicarbonate, sodium bicarbonate, or potassium chloride for 3 months. All subjects received calcium (600 mg of calcium as triphosphate) and 525 IU of vitamin D3 daily. At entry into the study and after 3 months, 24-Hr urinary N-telopeptide and calcium were measured in subjects. Changes in these measures were compared across treatment groups in the 162 participants included in the analyses. The results of the study found that bicarbonate affected the study outcomes whereas potassium did not; the two bicarbonate groups and the two no bicarbonate groups were therefore combined. Subjects taking bicarbonate had significant reductions in urinary N-telopeptide and calcium excretion, when compared with subjects taking no bicarbonate (both before and after adjustment for baseline laboratory value, sex, and changes in urinary sodium and potassium; P = 0.001 for both, adjusted). Potassium supplementation did not significantly affect N-telopeptide or calcium excretion. In conclusion, bicarbonate, but not potassium, had a favorable effect on bone resorption and calcium excretion. This suggests that increasing the alkali content of the diet may attenuate bone loss in healthy older adults.