Tryptophan can be used to synthesize niacin when the diet contains an adequate amount of protein. Option 4 is correct.
When there is enough protein in the diet, tryptophan can be utilized to generate niacin. The necessary amino acid tryptophan can be transformed by the body into the B-vitamin niacin.
The kynurenine pathway, a sequence of enzyme processes, is responsible for this conversion.
So, Tryptophan can be used to synthesize niacin when the diet contains an adequate amount of protein.
Therefore, Option 4 is correct.