Hypothyroidism & Folic Acid

Folate, or folic acid, is an essential B vitamin that is needed for the proper formation of red blood cells and their division and DNA synthesis. This vitamin shares an important, but somewhat indirect relationship with a condition known as hypothryoidism. If you have this condition and are not getting adequate folate in your diet, you could be at increased risk for heart disease.

Hypothyroidism is a disorder characterized by an underactive thyroid gland. The thyroid gland is located in the neck and produces hormones that regulate an array of bodily functions, including body temperature, mood, metabolism, heart rate and blood pressure. A deficit in hormones produced by the thyroid hormones, which act on every cell in the body, cause disruptions in many metabolic processes. Folic acid status is also affected by hypothyroidism.

Research published in the "Journal of Clinical Endocrinology and Metabolism" links low folate status to hypothyroidism. Low folate plays a role in elevated homocysteine levels; high levels of homocysteine are frequently seen in patients with hypothyroidism. Homocysteine is an amino acid that is synthesized in the body, and elevated levels increase risk of atherosclerosis, stroke, embolisms and heart attack. Low levels of folic acid are associated with elevated homocysteine because folic acid is utilized in the breakdown of homocysteine.

In healthy individuals, folic acid is converted to L-methyl folate, which is the biologically active form of the vitamin. Hypothyroidism causes a decrease in the activity of the enzyme methylenetetrahydrofolate reductase, which is responsible for producing L-methyl folate in the liver. Low levels of L-methyl folate result in excess levels of homocysteine. This indirect relationship could be causative in increasing cardiovascular disease risk in people with hypothyroidism.

People with subclinical hypothyroidism, which are those lacking overt symptoms of disease, are at greatly increased risk for atherosclerosis and subsequent heart attack or stroke. Due to the subtlety of their symptoms, they typically have not been diagnosed or treated for hypothyroidism. If you have hypothyroidism, you may benefit from supplementation or increasing sources of dietary folate. Leafy, green vegetables and beans can provide a substantial amount of folate to the diet.