Take vitamin D by mouth as directed. Vitamin D is best absorbed when taken after a meal but may be taken with or without food. Alfacalcidol is usually taken with food. Follow all directions on the ...

Take vitamin D by mouth as directed. Vitamin D is best absorbed when taken after a meal but may be taken with or without food. Alfacalcidol is usually taken with food. Follow all directions on the ...

Vitamin D2 is also known as "ergocalciferol," and vitamin D3 is also known as "cholecalciferol ... D needed to prevent rickets is 100 IU (2.5 mcg) per day in infants with little to no sun ...