Although the Dietary Reference Intake (DRI) for Vitamin D for Men

Although the Dietary Reference Intake (DRI) for Vitamin D for men and women is 600 IU per day, what value do many sport nutrition and health professionals recommend?

A) 100-200 IU per day
B) 300-400 IU per day
C) 5,000-10,000 IU per day
D) 1,000-2,000 IU per day