The american academy of pediatrics recommends that all infants should receive dietary supplements of until they take in this much from food sources.

The American Academy of Pediatrics is an organization that works to promote safety, health, and wellbeing of infants, children, and young adults. They recommended that infants who are breastfeeding or consuming less than a liter a day of infant formula receive vitamin D supplements by mouth. The amount should be 400 IU per day, until the infant can get vitamin D from plant milks or other foods.

because it travels in smaller waves then all other colors, causing it to be the most visible color