How does excess protein intake impact calcium?

How does excess protein intake impact calcium?

• A. Excessive protein enhances calcium excretion leading to negative calcium balance.
• B. Excessive protein increases calcium absorption.
• C. No effect on calcium balance.
• D. Leads to positive calcium balance.

Answer: (A)

Excess protein intake increases the body's acid load from metabolizing sulfur-containing amino acids. The kidneys respond by excreting more acid, and calcium is mobilized to help buffer this process, which raises urinary calcium excretion. If dietary calcium isn’t increased to offset these losses, the net calcium balance becomes negative. While protein can modestly boost intestinal calcium absorption, that effect typically doesn’t offset the greater urinary calcium loss seen with high protein intake, making a negative calcium balance the most likely outcome.

Excess protein intake increases the body's acid load from metabolizing sulfur-containing amino acids. The kidneys respond by excreting more acid, and calcium is mobilized to help buffer this process, which raises urinary calcium excretion. If dietary calcium isn’t increased to offset these losses, the net calcium balance becomes negative. While protein can modestly boost intestinal calcium absorption, that effect typically doesn’t offset the greater urinary calcium loss seen with high protein intake, making a negative calcium balance the most likely outcome.