A varied and healthy diet usually provides children with the vitamins and minerals they need for healthy growth and a strong immune system. It is generally not recommended to give children additional vitamins to "boost" their immune system without medical or nutritional advice. In some cases, such as with strict diets, food allergies, or nutrient absorption issues, a healthcare professional may recommend supplements. In Canada, it is recommended to give children vitamin D supplements, especially during the months when sunlight exposure is limited. Vitamin D can be found in foods like milk and fatty fish, but supplements may be needed to meet the recommended intake.