13C natural abundance in serum retinol acts as a biomarker for increases in dietary provitamin A. Academic Article uri icon


  • The natural isotopic composition of 13C and 12C in tissues is largely determined by the diet. Sources of provitamin A carotenoids (e.g., vegetables) typically have a lower 13C to 12C ratio (13C:12C) than preformed vitamin A sources (i.e., dairy and meat) from corn-fed animals, which are prevalent in the US. The 13C:12C of serum retinol (13C:12C-retinol) was evaluated as a biomarker for vegetable intake in a 3-mo dietary intervention designed to promote weight-loss by increased vegetable consumption or reduced calorie and fat intake. Subjects were 21-50 y of age with a BMI between 30-40 kg/m2 and were enrolled from one geographic area in the US. The high vegetable group (n=20) was encouraged to increase daily vegetable and fruit consumption to 0.95 liter vegetables and 0.24-0.35 liter fruits. The caloric reduction group (n=17) was encouraged to lower caloric intake by 500 kcal and consume

published proceedings

  • Exp Biol Med (Maywood)

author list (cited authors)

  • Howe, J. A., Valentine, A. R., Hull, A. K., & Tanumihardjo, S. A

citation count

  • 28

complete list of authors

  • Howe, Julie A||Valentine, Ashley R||Hull, Angela K||Tanumihardjo, Sherry A

publication date

  • February 2009