What effects does high protein intake have on calcium levels in the body?

High protein intake has been shown to increase calcium excretion in the body. This occurs because a high-protein diet, especially one rich in animal proteins, can lead to a rise in the acidity of the blood. To buffer this acidity, the body may release calcium from the bones, resulting in a greater amount of calcium being excreted through the urine.

Research indicates that while protein is essential for many bodily functions, excessive protein intake can lead to higher levels of sulfuric acid due to the metabolism of sulfur-containing amino acids. The kidneys then increase calcium excretion as a response to this increased acidity, which can have implications for bone health if calcium loss is substantial over time.

In contrast, other options suggest outcomes that are not supported by current nutritional science. Increasing calcium absorption or reducing calcium requirements would imply a beneficial effect on calcium retention, while stating that there is no effect contradicts the observed physiological responses to high protein intake. Thus, the assertion that high protein intake increases calcium excretion aligns with established research on nutrition and human physiology.