Question

Describe what is known about the relationship between protein intakes (both low and high) and bone health.​ Be specific.

Answer 1

Proteins are the macromolecules which consist of amino acids and are connected by peptide bonds. Protein make about one third of mass of a bone and 50% of its volume. So it is necessary to include protein in daily intake of food. A continuous supply of amino acids and minerals are needed for proper growth and maintenance of bone across life span.
The recommended dietary allowance of protein is   0.8 g/kg body weight/ day.

•   High intake of protein-

High protein intake affects calcium homeostasis leads to more amount of calcium excretion through urine. This leads to chance of fractures and osteoporosis. As there is increase in urinary calcium there is chance of developing negative calcium balance.
•   Low protein intake-
Low protein intake have adverse effect on bone health. Low protein intake lower than the normal range recommended leads to reduced intestinal calcium absorption and leads to increased level of parathyroid hormone which in turn leads to release of calcium from bone.
The insulin- like growth factor ( IGF-1) which plays a major role in bone metabolism also affected by alteration in protein level. High IGF-1 level are autotrophic.
High protein diet is associated with less chance of fracture and increased bone mass and when the calcium intake is adequate.