Blocked arteries cause high blood pressure, or hypertension. High blood pressure puts you at risk for stroke, heart attacks, kidney damage and blindness. Each class of blood pressure medicines carries differing risks for interacting with other drugs or supplements. But if you take a B-complex vitamin or individual supplements of B-6 or B-12, you are unlikely to lower the effectiveness of your antihypertension drug.
Blood Pressure Medications
Depending on the suspected cause of your hypertension, your doctor will prescribe a specific antihypertension drug. Among the medications used to lower blood pressure are beta-blockers to slow heartbeat and reduce pressure against arterial walls, and alpha-blockers to encourage blood flow through arteries by relaxing blood vessels. As the name suggests, alpha-beta blockers combine the benefits of both beta- and alpha-blockers. Diuretics reduce pressure by flushing extra sodium, a mineral associated with fluid retention, from your system. Vasodilators expand blood vessels, enabling blood to flow more freely. Other antihypertension drugs also exist, each with its own set of potential side effects and drug interactions. Always check with your physician about diet, medication and lifestyle changes you should make to lower your blood pressure and to prevent drug interactions.
Vitamins B-6 and B-12
Vitamins B-6 and B-12 may work to lower heart disease risk by decreasing the level of a specific amino acid in your blood. Doctors associate this amino acid, homocysteine, with increased incidents of heart disease, although more research is needed to determine if supplemental vitamins will ward off cardiovascular issues. According to the University of Maryland Medical Center, getting enough B-6 also shows promise for stabilizing moods and easing inflammation for conditions such as rheumatoid arthritis and carpal tunnel syndrome. A lack of B-12 in your diet could lead to fatigue, mental confusion and nerve damage. Both vitamins are found in fish, liver and dairy foods. Wheat germ, sunflower seeds, brown rice, beans, spinach and carrots also provide B-6, while pork, eggs and beef contribute B-12.
Negative Drug Interactions
Supplements of vitamins B-6 and B-12 are not known to decrease the effectiveness of blood pressure medicine. Both vitamins may make tetracycline, an antibiotic, less effective if they are taken at the same time of day. In addition, vitamin B-6 may interfere with phenytoin, an anti-seizure drug, as well as levodopa, which treats Parkinson's disease.
Just as some supplements may lower the effectiveness of prescription medications, drugs can reduce the level of specific nutrients in your body. The University of Maryland Medical Center notes that one blood pressure medication, hydralazine, can reduce levels of vitamin B-6 in your system. Hydralazine, also known as apresoline, is a vasodilator. This type of blood pressure medication works by helping to expand blood vessels. If you take this type of blood pressure medicine, ask your physician if eating more foods rich in vitamin B-6, or taking a supplement, might be helpful to prevent a vitamin deficiency.