High blood pressure, which can damage blood vessels, is a major cause of heart disease. Also known as hypertension, high blood pressure is treated with a number of different types of anti-hypertensives, or blood pressure lowering medications. Niacin, one of the B-complex vitamins, can lower blood pressure in some cases but is not generally used by traditional medical practitioners for this purpose. Niacin, or B-3, can have significant side effects and should not be taken to lower blood pressure without your medical practitioner's approval.
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Niacin acts as a vasodilator, which means it helps to relax blood vessels and open them wider. Hypertension develops when blockages in blood vessel walls or stiffening of the walls forces the heart to work harder to pump blood to organs and tissues throughout the body. When arteries widen, the heart doesn't need to pump so hard to move blood through the body, and blood pressure drops.
Hypotension As a Side Effect
When used to treat other conditions, niacin can cause low blood pressure as a side effect. MedlinePlus cautions not to take niacin if you have low blood pressure, because it can lower it even further, causing you to become dizzy or even pass out. The University of Maryland Medical center warns against taking niacin with blood pressure medications without your doctor's approval, because niacin could increase the effects of blood pressure medications, causing hypotension.
Other Side Effects
Because niacin is a vasodilator, it can also dilate blood vessels that lead to the skin's surface if taken in doses of excess of 50 mg. One of the best-known side effects of niacin is the niacin flush, reddening of the skin and a burning, tingling sensation on the face, neck and chest. Niacin can also cause liver or kidney damage, increase blood glucose levels, cause stomach ulcers, worsen allergy symptoms and cause an irregular heartbeat. Do not take niacin without first consulting your medical practitioner.
Considerations
Niacin may lower blood pressure, but it also has a number of potentially serious side effects, including many drug interactions with other drugs. In a January 2009 study published in the "International Journal of Clinical Practice," researchers from the Louisville Metabolic and Atherosclerosis Research Center of Kentucky noted that, while long-term use of niacin may have benefits in lowering blood pressure, further study is needed to evaluate its effects.
