Whether taking one capsule of cod liver oil a day is good for the body varies from person to person. Normal healthy people don’t need to take cod liver oil, while for patients with vitamin A and vitamin D deficiencies, taking cod liver oil is beneficial, but how many capsules a day should be taken according to the doctor’s instructions. Cod liver oil is a kind of fatty oil raised from the liver of non-toxic marine fish, and its main components are vitamin A and vitamin D₃, the amount of vitamin A and vitamin D₃ contained in different specifications of cod liver oil is also different, and patients suffering from rickets, nocturnal blindness, and pediatric hand and foot tics can take cod liver oil according to the doctor’s prescription. It should be noted that long-term use or overdose can make vitamin A, vitamin D₃ accumulation in the body, resulting in chronic toxicity, the patient can appear bone and joint swelling, skin pain and itching, dry and cracked lips, weakness, fever, headache, vomiting, constipation, diarrhea, nausea and vomiting and other symptoms. In addition, patients with chronic renal failure, patients with hypercalcemia, and patients with hyperphosphatemia with renal rickets are prohibited from taking this drug. If you need to take cod liver oil, please under the guidance of a physician or pharmacist.