HOMOCYSTEINE
Homocysteine is an amino acid (protein precursor). Elevated homocysteine levels are associated with increased risk of atherosclerosis (heart attack and stroke) and venous thromboembolic disease (thrombophlebitis and pulmonary embolism). Elevated levels have been found in 10-30% of patients with a heart attack and in a large number of patients with chronic renal (kidney) failure. Whether or not homocysteine is a contributor to atherosclerosis or the result of the disease is as yet unproven. However, there is mounting evidence that it not only adversely affects the walls of blood vessels but also the clotting system. It, therefore, seems prudent to treat patients with proven atherosclerosis and elevated levels.
Treatment consists of relatively high doses of folic acid (1 mg once or twice daily). If the homocysteine level remains high, then one adds vitamin B12 (500 mg once or twice daily). Finally, if the level is persistently high, then one adds a third B vitamin, pyridoxine (100 mg once or twice daily).
It should be noted that each laboratory may report a different range of normal.