What Is Homocysteine?
Homocysteine is an amino acid formed in the body from another amino acid called methionine. Certain B vitamins are needed to breakdown these amino acids. The vitamins include vitamin B6, vitamin B12, and folate. A deficiency of any one of these vitamins, most particularly folate, can lead to an elevation in blood levels of homocysteine.
Does Homocysteine Increase the Risk of Heart Attack?
Levels of homocysteine increase with age, and elevation is more common in men and postmenopausal women. Although some studies have found an association with high homocysteine levels and heart disease, whether or not homocysteine is a risk factor for heart disease remains controversial.
During the last several years, a connection between mild to moderate elevations of homocysteine and heart disease has shown up in some, but not all studies. Organizations like the American Heart Association (AHA) do not currently identify high homocysteine levels as a major risk factor for cardiovascular disease.
Do not be surprised if your doctor is somewhat reluctant to measure your homocysteine level. If other risk factors for heart disease are already present, knowing that your homocysteine level is elevated most likely not change your treatment. However, according to the AHA, getting screened for homocysteine levels may be useful if you have a personal or family history of cardiovascular disease and do not have the common risk factors, like smoking, high blood pressure, high cholesterol.
What If You Have Elevated Homocysteine Levels?
Homocysteine levels are reduced when intake of folate, vitamin B6, and vitamin B12 is increased. However, studies have not shown that taking these vitamins can prevent or treat cardiovascular disease.
The AHA suggests that people at high risk should make sure they are getting enough folate, vitamin B6, and B12 in their diet. Your doctor can give you specific recommendations about the appropriate dosages for you. Here are the general recommendations for daily intake of folate, vitamin B6, and B12:
- Males and females aged 14 and older—400 micrograms (mcg)
- Vitamin B6
- Males aged 19-50 years—1.3 milligrams (mg)
- Males aged 51 years and older—1.7 mg
- Females aged 19-50 years—1.3 mg
- Females aged 51 years and older—1.5 mg
- Vitamin B12
- Males and females aged 14 years and older—2.4 micrograms
Here are a few examples of foods that are high in these vitamins:
- Folate—citrus fruits, fortified breakfast cereal, vegetables
- Vitamin B6—fortified breakfast cereal, bananas, baked potatoes with skin
- Vitamin B12—fortified breakfast cereal, fish, meat, poultry, and dairy products
If you are concerned about your risk factors for heart disease or if you would like to take supplements, talk to your doctor to decide what the best approach would be based on your health and diet.
American Heart Association
National Heart, Lung, and Blood Institute
Heart and Stroke Foundation of Canada
Folate. Office of Dietary Supplements—National Institutes of Health website. Available at: https://ods.od.nih.gov/factsheets/Folate-HealthProfessional. Updated April 20, 2016. Accessed December 9, 2016.
High homocysteine level: How it affects your blood vessels. Family Doctor—American Academy of Family Physicians website. Available at: https://familydoctor.org/high-homocysteine-level-how-it-affects-your-blood-vessels. Updated May 2014. Accessed December 9, 2016.
Homocysteine and cardiovascular disease. EBSCO DynaMed Plus website. Available at:http://www.dynamed.com/topics/dmp~AN~T116463/Homocysteine-and-cardiovascular-disease. Updated August 23, 2016. Accessed December 9, 2016.
Liem A, Reynierse-Buitenwerf GH, Zwinderman AH, Jukema JW, van Veldhuisen DJ. Secondary prevention with folic acid: effects on clinical outcomes. J Am Coll Cardiol. 2003;41(12):2105–2113.
Pyridoxine. EBSCO DynaMed Plus website. Available at:http://www.dynamed.com/topics/dmp~AN~T233208/Pyridoxine. Updated December 7, 2016. Accessed December 9, 2016.
Schnyder G, Roffi M, Flammer Y, Pin R, Hess OM. Effect of homocysteine-lowering therapy with folic acid, vitamin B12, and vitamin B6 on clinical outcome after percutaneous coronary intervention: the Swiss Heart study: a randomized controlled trial. JAMA. 2002;288(8):973–979.
Vitamin B6. Office of Dietary Supplements—National Institutes of Health website. Available at: https://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional. Updated February 11, 2016. Accessed December 9, 2016.
Vitamin B12. Office of Dietary Supplements—National Institutes of Health website. Available at: https://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional. Updated February 11, 2016. Accessed December 9, 2016.
Last reviewed December 2016 by Michael Woods, MD Last Updated: 12/9/2016