Is it time to move beyond serum retinol concentrations to evaluate interventions and set policy?
Wednesday, 11 September 2013
12:00 to 13:00, Salle G (8th floor - main building)
Dr. Sherry A. Tanumihardjo
University of Wisconsin-Madison, Department of Nutritional Sciences
Madison, Wisconsin, United States of America
Vitamin A is essential for multiple functions in mammals. Without vitamin A, mammals cannot grow, reproduce, or fight off disease. Because of its numerous functions in humans, biomarkers of vitamin A status are quite diverse. Assessment of liver reserves of vitamin A is considered the gold standard because the liver is the major storage organ. However, this measure is not feasible in human studies. Alternative biomarkers of status can be classified as biological, functional, histologic, and biochemical.
Before overt clinical damage to the eye, individuals who suffer from vitamin A deficiency are plagued by night blindness and longer vision-restoration times. These types of assessments require large population-based evaluations. Therefore, surrogate biochemical measures of vitamin A status, as defined by liver reserves, have been developed. Serum retinol concentrations are a common method used to evaluate vitamin A deficiency. However, they often do not respond to interventions and do not decline until liver reserves are severely depleted. Therefore, surrogate measures of liver reserves have been developed, which include stable isotope and relative dose response tests.
Evidence and Programme Guidance Unit, Department of Nutrition for Health and Development