Hyperhomocysteinemia (HCY) is a risk factor for many diseases, especially coronary atherosclerosis, Alzheimer’s disease, stroke and other cardiovascular diseases. Increased HCY in the blood causes damage to the arterial vessels because of irritation of the vessel walls, leading to inflammation and plaque formation in the vessel walls, and ultimately causing obstruction of blood flow to the heart, making hyperhomocysteinemia an independent and important risk factor for coronary heart disease. Methionine metabolism disorders can lead to hyperhomocysteinemia, and the causes of methionine metabolism disorders are both genetic and environmental nutritional factors. Genetic factors cause deficiency or reduced activity of three key enzymes, namely methylenetetrahydrofolate reductase, cystathionine condensase, and methionine synthase. Environmental nutritional factors refer to a high methionine content in a diet high in animal protein, which can lead to elevated HCY levels, and deficiencies in metabolic cofactors such as folic acid and vitamins B6 and B12, which are essential for homocysteine metabolic reactions and can lead to the development of hyperhomocysteinemia. There are no drugs specifically for the treatment of hyperhomocysteinemia, but the treatment of hyperhomocysteinemia is actually very “simple”, mainly supplementing with folic acid, vitamin B6 and vitamin B12, which are essential nutrients that can be obtained from the daily diet, such as green leafy vegetables, fruits, nuts, eggs, beans, yeast, animal liver, kidney, etc. Therefore, the key to treating hyperhomocysteinemia is to adjust the diet. In principle, it should be appropriate to eat more green leafy vegetables, fruits, animal liver and kidney, etc., and less red meat, white meat, beans, seafood, etc., because these foods are rich in methionine, which will be converted into homocysteine after entering the body. Specifically, you should consume 500 grams of vegetables and 200 grams of fruits every day, especially more leafy greens; strictly control meat intake, not fatty meat, eat lean meat not more than 100 grams a day; eat beans five times a week, about 50 grams each time; eat animal liver and kidney once or twice a week, about 25 to 50 grams each time; eat more brown rice, whole grain foods and other coarse grains. In addition, you should quit smoking and limit alcohol, eat less salt (no more than 6 grams per day), and drink less coffee, etc. For people with moderate to severe hyperhomocysteinemia, in addition to dietary adjustments, “medication” can be administered under medical supervision, i.e., folic acid, vitamin B6, and vitamin B12 supplements. These are essential nutrients and therefore safe and reliable to take in appropriate amounts over a long period of time.