Can Magnesium Cause High Blood Pressure?

If your blood pressure is higher than 140 systolic over 90 diastolic you may have high blood pressure, also known as hypertension. According to MedlinePlus, high blood pressure affects one in three adults and increases your risk for heart disease and stroke, the first and third leading causes of death in the United States. You may not have any signs or symptoms with hypertension so get your blood pressure checked regularly.


The adult body contains 25 grams of magnesium and 60 percent of it is found in the bones. Magnesium is responsible for more than 300 biochemical reactions, such as metabolizing carbohydrates and fats. It is required for protein synthesis, it helps create genetic material and transports ions, which are electrically charged particles, across cell membranes. It is absorbed in the small intestine and green vegetables are a good source of magnesium because of the chlorophyll.

Magnesium and Blood Pressure

Research shows that magnesium affects blood pressure and although the evidence is limited, low levels may play a small role in contributing to hypertension. Despite this modest effect, most studies indicate that the right amount of magnesium actually lowers blood pressure. A review in the November 2011 "Journal of Clinical Hypertension" explains that magnesium intake can lower blood pressure by 5 to 6 points. The review reports that magnesium also increases the effectiveness of blood pressure medications. Although the mechanism is not completely understood, it is theorized that this decrease is due to the interaction of magnesium, fiber and potassium, which are present in magnesium-rich foods like fruits and vegetables. Eating a diet rich in magnesium can both lower and serve as a protective factor against hypertension.

Dietary Requirements

The daily requirement for dietary magnesium is based on age and sex. For example, men between the ages 19 and 30 need 400 milligrams of magnesium and women require 310 milligrams. Men and women older than age 31 need 410 milligrams and 320 milligrams of magnesium, respectively. Good sources of magnesium include halibut, dry roasted almonds and cashews, frozen spinach, Swiss chard, lima beans, fortified cereals, and oatmeal.


In addition to eating a diet rich in magnesium, there are other things you can do to help lower your blood pressure or decrease your risk for developing hypertension. Avoid eating a high-sodium diet by limiting your intake to less than 1,500 milligrams a day. You can also decrease your sodium levels by eating less processed foods. Other preventive measures include eating less fat, especially saturated fat, exercising regularly to maintain a healthy weight and limiting your intake of alcohol.