No major studies, however, have been done on long-term benefits or risks of magnesium supplements. Calcium regulates the tone of the smooth muscles lining blood vessels, and population studies have found that people who have sufficient dietary calcium have lower blood pressure than those who do not. Hypertension itself increases calcium loss from the body. Some, but not all, studies have found modest beneficial effects on blood pressure from calcium supplements. One study found protection against stroke in men whose diets were rich in magnesium and potassium but no similar effects from diets high in calcium.
Sufficient calcium is important, in any case, for strong bones health.
Vitamin C. Vitamin C apparently has specific benefits for hypertension by preventing dangerous effects on nitric acid, the substance that keeps arteries flexible. Caffeine Intake, Alcohol, and Smoking Everyone should quit smoking and if they drink alcohol at all, do so in moderation. In healthy people with normal blood pressure drinking a couple of cups of coffee a day is unlikely to do any harm. Caffeine drinkers, however, would do better to choose tea, which may have beneficial nutrients, and people with existing hypertension should avoid caffeine altogether. Exercise Studies indicate that regular exercise helps keep arteries elastic, even in older people, which in turn keeps blood flowing and blood pressure low.