Children's Vitamin Supplement 250% DV per Serving Vitamin D Boosts Bone and Tooth Health Suitable for Vegetarians Yummy Berry Flavor Helps Calcium Absorption and Supports a Healthy Immune & Nervous System. The best source of Vitamin D is sun exposure since our skin manufactures Vitamin D upon exposure to sunlight. However, during the winter months sun exposure is limited. And in the summer, because we have to protect our children against skin disease, we use sunscreen which reduces the skin's ability to produce vitamin D. Only a few foods contain vitamin D naturally such as fatty fish, milk, egg yolks, some cheese and some meats including liver. It can be very difficult to ensure your child takes in sufficient amounts of vitamin D.