Which factors may lead to decreased blood urea levels?

Decreased blood urea levels can be significantly influenced by low dietary protein intake. Blood urea nitrogen (BUN) levels are primarily a result of protein metabolism; as proteins are broken down in the body, amino acids are converted into urea in the liver, which is then excreted by the kidneys. When there is insufficient protein intake in the diet, the production of urea decreases because there are fewer amino acids available for metabolism. This can lead to lower BUN levels in the blood, indicating a decreased protein synthesis or absorption.

Other factors may affect blood urea levels, but they do not have the same direct relationship with dietary protein. For instance, gastrointestinal tract bleeding typically leads to increased urea levels due to higher absorption of blood proteins, while overhydration could dilute blood urea concentration but is less directly related to protein metabolism. Steroid use might influence metabolism and muscle mass but does not specifically lead to decreased urea levels through a direct mechanism related to protein intake.