The main nutrient of cod liver oil is vitamin D. Generally, nine-month-old babies don’t need to take cod liver oil and vitamin D at the same time, and one of the two will do. Nine months baby growth and development is very fast, in order to avoid the occurrence of vitamin D deficiency rickets and other undesirable diseases, you can quantitatively give your baby vitamin D supplementation under the guidance of the doctor, the daily supplementation amount is about 400~800 IU. generally nine months baby does not need to take cod liver oil and vitamin D at the same time, both eat one can be enough. When babies supplement vitamin D preparations, you can release the small vitamin D gel pills into a small spoon and feed your baby with a small spoon, which is the safest and most effective. It is absolutely forbidden to squeeze the vitamin D gel pills directly into children’s mouths, as it may have the risk of causing children to get stuck. Sunshine is a good way for babies to supplement vitamin D. You can expose your baby’s face and limbs to the sun for about 15 to 30 minutes, but proper sunscreen treatment is required under exposure to the sun. Vitamin D supplementation should be done under a doctor’s supervision to avoid delays or adverse reactions.