Vitamins D and C and the minerals zinc and selenium contribute to the normal function of the immune system. Vitamin D and zinc contribute to the maintenance of normal bones and skin and normal muscle function. Selenium and zinc contribute to maintaining healthy and normal hair and nails. Vitamin C contributes to the normal production of collagen for the function of bones, cartilage, gums, skin and teeth. Although in clinical practice vitamin D was intended for infants and the elderly, new research has shown the need to take vitamin D in all age groups in the months (October to April) when sun exposure is insufficient to prevent chronic vitamin D deficiency that has over 40% of the population. Effect of vitamin D on cells of the respiratory system: reduces inflammation, reduces the risk of acute respiratory distress syndrome and reduces the risk of pneumonia and infection.