Michael's Naturopathic, PreTeen Boys Daily Multi Vitamin, 60 TabsProduct Description Pre teen boys multi vitamins healthy growth and development is for vitamin A for growth, immune system and bone growth is for healthy tooth development. Vitamin C is essential for connective tissue, bones, cartilage, skin, immune system function. Zinc for all cellular growth and for healthy reproductive system development, essential for the immune system needed for carbohydrate metabolism because of role as co factor in insulin