Summer, is a high incidence of cardiovascular disease season, in the hot weather above 35 ℃, cardiovascular disease mortality rate increased significantly, so the high temperature is very harmful to cardiovascular disease patients. Many patients with cardiovascular disease think that the lowest blood pressure in the summer of the year, the symptoms will be relatively stable, in fact, not, summer is the peak of the incidence of cardiovascular disease, we have to do a good job of prevention, especially for the elderly, summer should be appropriate to supplement some folic acid. As we all know, the increase in blood flow to the skin of middle-aged and elderly people in summer is not as good as that of young people, so during the hot weather, the elderly are more prone to heatstroke, stroke and the risk of heart attack. The reason for this is that older people are unable to produce enough nitric oxide in their blood vessels. An enzyme called BH4 is essential for blood vessels to produce enough nitric oxide. As we age, BH4 bioavailability decreases. Early studies have found that if BH4 enzyme levels are increased in middle-aged and older adults, more of the vascular-healthy nitric oxide can be produced. Folic acid, on the other hand, can increase nitric oxide levels in the body through BH4 enzymes. In addition, folic acid is an important cofactor in the metabolism of homocysteine, and a deficiency of folic acid can cause an increase in the serum concentration of homocysteine, which in turn is a cardiovascular disease risk factor. Homocysteine can be found everywhere in our body and promotes the growth of smoother muscle cells in the walls of blood vessels, creating a favorable environment for blood clotting, leading to arterial obstruction and heart attacks. It has been found that as long as homocysteine is slightly high, it will eventually cause narrowing of coronary artery diameters, thrombosis and occlusion, thus triggering cardiovascular disease, so proper supplementation of folic acid is beneficial to the health of cardiovascular disease patients. Folic acid is a B vitamin essential for the growth and development of every cell in the human body. Natural foods rich in folic acid include legumes such as beans, lentils, garbanzo beans and black beans, as well as green leafy vegetables such as spinach, asparagus and broccoli, and citrus fruits such as oranges and grapefruit. Proper folic acid supplementation for seniors in the summer can help dilate blood vessels, promote blood flow through the skin, and reduce the risk of cardiovascular disease.