Quest Vitamin D provides 4000iu of vitamin D per tablet. Vitamin D contributes to the normal function of the immune system & muscles. It is needed for the utilisation of calcium in the body & helps to maintain bones & teeth. Vitamin D is naturally created by the body through exposure to sunlight, & may be recommended as a supplement for individuals with limited exposure to sunlight. Directions for Use One chewable tablet with or after a meal. Do not exceed the stated dosage unless instructed by a qualified health professional.