Holland & Barrett's Cod Liver Oil is high in omega-3 fatty acids and provides an excellent source of vitamins A and D. Both vitamins A and D contribute to the normal function of the immune system. Vitamin A also contributes to the maintenance of normal skin, whilst Vitamin D contributes to the maintenance of normal bones and muscle function. DHA contributes to the maintenance of normal brain function and vision and when combined with EPA, they contribute to the normal function of the heart. These beneficial effects are obtained with a daily intake of 250mg of EPA and DHA.