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 ...

Consequently, the dose of vitamin D also varied considerably, ranging from 1250 to 7500 mcg in the single-dose studies and effective daily doses ranging from 0.5 to 3750 mcg in those that administered ...