Quest Vitamin D3 and DHA drops combine two essential nutrients in one convenient formula for infants and children aged between one month and five years old. Vitamin D is an essential vitamin for children, it contributes to the growth and development of bones. The UK Department of Health recommends that all infants and young children aged 6 months to 5 years should take a vitamin D supplement. Vitamin D also helps to maintain teeth and contributes to the normal function of the immune system and muscles. DHA contributes to normal brain function and maintenance of normal vision. This beneficial effect may be obtained with a minimum daily intake of 250mg of DHA.