The efficacy and contraindications of cod liver oil

Cod liver oil is a food that many people love to eat nowadays, but there are also many taboos. Try not to consume it in excess, otherwise it will definitely have a great impact on your body. If you take it in excess, it will cause you to lose weight. If the patient is in a serious condition, it may directly affect the cardiopulmonary function, causing great damage to the heart.

Vitamin D

Vitamin D helps ensure the body absorbs and stores calcium and phosphorus. Vitamin D deficiency can lead to rickets, osteomalacia, etc. Vitamin D deficiency is very common in China due to insufficient outdoor activities, haze, sun protection, and lack of fortified foods. There are very few foods that contain vitamin D naturally. Fatty fish and cod liver oil are the best food sources of vitamin D.

Overdose Risk

Excess vitamin D can cause some non-specific symptoms, such as anorexia, weight loss, polyuria, arrhythmia, etc. What is more serious is that it may cause calcification of blood vessels and tissues by increasing blood calcium levels, damaging the heart, blood vessels and kidneys. Postmenopausal women who supplement with 1000 mg of calcium and 400 IU of vitamin D may have a 17% increased risk of kidney stones.

The maximum tolerable intake is: 1000 IU for 0-6 months, 1500 IU for 6-12 months, 2500 IU for 1-3 years, 3000 IU for 4-8 years, and 4000 IU for ≥9 years.

Vitamin A

Vitamin A is very helpful for maintaining normal visual function, immune system and reproductive system health. It can be obtained through animal liver, green, yellow and orange vegetables, fish such as salmon, fruits such as mango, and dairy products. In theory, it is not easy to be deficient except for premature infants, children and pregnant women in underdeveloped areas. However, chronic diarrhea may cause loss of vitamin A, leading to symptoms such as dry eyes, night blindness and anemia. The vitamin A deficiency rate among children in my country can reach more than 10% in some areas, and the proportion of subclinical vitamin A is even higher, which can reduce children's body resistance and cause a high incidence of infectious diseases such as respiratory and digestive tract diseases.

Overdose Risk

There were reports of poisoning from eating polar bear liver as early as the 16th century. Long-term intake of vitamin A exceeding 33,000 IU can lead to chronic poisoning, resulting in baldness, movement disorders, pain, etc. Adults who consume more than 66,000 IU at a time will immediately experience symptoms such as vomiting and headache. Generally, it is not recommended to exceed 10,000 IU for daily supplementation. But at the same time, vitamin A deficiency in children is not uncommon (3%~50% in different regions of the country). Symptoms of poisoning: dizziness, nausea, pain and even death.