By utilizing novel stable isotope dilution techniques recently developed in our laboratory, we will trace deuterium labeled ß-carotene in intrinsically labeled spirulina, which is harvested from a hydroponic system. In the mean time, we will track 13C10 labeled vitamin A in humans. In this way we will determine absorption of ß-carotene from spirulina matrix and the conversion of the spirulina ß-Carotene to retinol. This will enable us quantitatively determine the vitamin A equivalence of spirulina.
The specific aims of this study are:
1. To determine labeled ß-C blood response kinetics following an acute dose of intrinsically labeled spirulina;
2. To determine labeled retinol blood response from the intrinsically labeled spirulina;
3. To determine 13C10 retinol blood response from the isotope reference material 13C10 retinyl acetate;
4. To determine s spirulina-vitamin A equivalence.
