Hypertensive patients take 5mg of folic acid a day is too much, if you take it for a long time may be folic acid overdose, causing some adverse reactions or side effects. Generally speaking, for hypertensive patients with relatively high homocysteine, you need to supplement folic acid 0.4-0.8mg per day can be, but also supplement vitamin B6, vitamin B12, can reduce homocysteine, thus reducing hypertension and cardiovascular and cerebral vascular disease risk factors, if the dosage is too large, it can result in the following situations: 1. excessive aggregation of folic acid: excessive aggregation of folic acid will affect the absorption of zinc in the body, affecting the body’s immunity, affecting the growth and development of the child and so on. 2. Causing gastrointestinal reactions: for example, excessive folic acid can cause digestive symptoms, nausea, vomiting, indigestion and so on. 3. Mask the symptoms of vitamin B deficiency: for example, malnutrition leads to vitamin B6 and vitamin B1 deficiency, and neurological damage. In conclusion, patients with high blood pressure who have elevated homocysteine should take folic acid supplements under the guidance of a professional doctor and according to the specific circumstances, and should not take them blindly to avoid excessive dosage, which may lead to some side effects or adverse reactions.