proteincalcium

ANNUAL MEETING

HIGHLIGHTS

Dietary Protein Affects Calcium Metabolism

Presented by Donna Caseria, MS, RD, Yale University

Reviewed by Linda Brinkley, MS, RD

Protocol Description:

16 healthy Asian and Caucasian females, ages 20 - 40 years, normal weights

Diet:

--The Basic Diet was kept constant at 800 mg Calcium, 800 - 1200 mg

Phosphorus, and 100 meq Sodium.

--The variable was dietary protein levels. Protein levels of 0.7 g/kg, 0.8 g/kg, 0.9 g/kg, 1.0 g/kg, and 2.1 g/kg Body Weight were used.

--Fiber content was the same in low protein diets and in the moderate protein diets.

Results: Protein levels of 0.7 g/kg and 0.8 g/kg B.W. resulted in increased PTH and Vitamin D in all subjects. Urinary calcium was also decreased in these subjects. The percent calcium absorption was low on the low protein diet and normal on the high protein diet. At 2.1g protein/kg B.W. subjects had hypercalciuria and PTH was normal to decreased. At 0.9 g/kg and 1.0 g/kg B.W. the PTH and urinary calcium were normal. The usual protein intake for these women was estimated to be 1.0 - 1.5 g/kg B.W. Therefore, the RDA for protein of 0.8 g/kg B.W. may be too low to maintain bone health.