C. Perfecto

Bioconversion of plant carotenoids to vitamin A in Filipino school-aged children varies inversely with vitamin A status.

R. Russell, C. Fjeld, J. Ribaya-Mercado, 2000, The American journal of clinical nutrition.

Dietary vitamin A intakes of Filipino elders with adequate or low liver vitamin A concentrations as assessed by the deuterated-retinol-dilution method: implications for dietary requirements.

R. Russell, G. Dolnikowski, J. Ribaya-Mercado, 2004, The American journal of clinical nutrition.

Evaluation of the effect of vitamin A-fortified margarine on the vitamin A status of preschool Filipino children.

A. Sommer, K. West, J. Sarol, 1996, European journal of clinical nutrition.