Pellagra, a deficiency of vitamin B3 (niacin), can be secondary to a recurrent carcinoid tumor. Carcinoid tumors produce serotonin, which is a derivative of tryptophan. However, tryptophan is also the precursor of niacin. In patients with carcinoid tumors, the tumor can be so active that most tryptophan is used for serotonin production, resulting in niacin deficiency. [1]
References
1. Richard J. Castiello, MD; Peter J. Lynch, MD. Pellagra and the Carcinoid Syndrome. Arch Dermatol. 1972;105(4):574-577. doi:10.1001/archderm.1972.01620070046016.
Obstructive sleep apnea (OSA) is thought to lead to secondary polycythemia due to intermittent hypoxia,…
Catabolism of hemoglobin leads to the release of heme, which converts to biliverdin and then…
Tongue scalloping refers to the series of indentations along the sides of the tongue that…
Older age is recognized as a risk factor for obstructive sleep apnea.[1] But why? Suspected…
Being overweight (BMI ≥ 25 kg/m2)/Obese (BMI ≥ 30 kg/m2) is one of the most…
Nocturia is a common symptom associated with obstructive sleep apnea. [1] Img Cred: Am J…
This website uses cookies.