While breastmilk has a near-perfect nutritional profile for infants, breastmilk is low in vitamin D. Formula-fed infants who do not receive much sunlight may also be at risk for vitamin D deficiency. The American Academy of Pediatrics recommends that all children receive how much vitamin D per day?

According to the American Academy of Pediatrics, all infants and older children should receive 400 IU of vitamin D per day and adolescents should receive 600 IU of vitamin D per day.  

Explanation:

Vitamin D is an essential nutrient for building bones. It is responsible for the absorption of calcium, phosphorus, magnesium, etc in the body. Foods that are rich in vitamin D include mushrooms, dairy products, egg yolks, fatty fish like tuna, mackerel, salmon, etc. The deficiency of vitamin D increases the risk of bone fractures, bone pain, and muscle weakness. It also leads to a bone-softening disease known as rickets.

According to the American Academy of Pediatrics, all breastfed babies and non-breastfed infants should receive a vitamin D supplementation of 400 IU per day since breastmilk is low in vitamin D and due to decreased sunlight exposure. All infants and older children should receive 400 IU of vitamin D per day and adolescents should receive 600 IU of vitamin D per day.

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds