Baylor Infant Biomarker of Nutrition Study

Inclusion Criteria: * 4-4.5 months old at baseline * born at term (\>/=37 weeks gestation) * within the 5th-95th weight-for-age percentile (inclusive) * primary caregiver can speak, read, and understand English * infants are exclusively breast- and/or formula-feeding at baseline * consenting parent or caregiver must be 18 years old or older Exclusion Criteria: * has a sibling enrolled in the study * metabolic, digestive, or malabsorptive disorders * known bleeding or clotting disorder * requires a special diet * exposed to tobacco smoke in the home * currently taking any isolated carotenoid supplements * using medications or complementary or alternative medications that interfere with dietary fat absorption * has a history of endocrine disorders requiring hormone administration.