the data from several clinical and epidemiological studies, the presence of an
abnormally large concentration of homocysteine (tHcy) in the blood has been
identified as a risk factor for cardiovascular disease. Folate deficiencies are
responsible for majority of the hyperhomocysteinemia cases in the general
population. To reduce
elevated tHcy levels, vitamin B supplements, particularly those containing
folic acid, have been proven to be an efficient, safe, and inexpensive measure.
tHcy concentration of 5 – 15 µM is considered normal, with the average tHcy
concentration working out to be approximately10 µM in healthy individuals. On
the other hand, an individual is considered to have hyperhomocysteinemia if
their plasma tHcy exceeds 15 µM. These values however did vary from study to
study most likely due to different sample handling/methodology and genetic variations
(i.e. metabolic disorders) amongst different populations. Overall, it has been
noted that tHcy concentrations are higher in men and increase with age.
In the late 1980s, one study showed
a decrease in tHcy levels in healthy patients following the intake of supplements
with large doses (5 mg/d) of folic acid. These results are consistent with
those obtained from follow-up studies. Overall, the consensus in the scientific
community is that a folate intake of 0.65 – 10 mg/d folic can decrease tHcy
levels by roughly 25.50%. In populations consuming an adequate amount of B
vitamins (i.e. from dietary sources or supplements), the maximal tHcy
concentration is around 12 µM.
In addition, studies have
demonstrated that folic acid is nontoxic at extremely high doses, thereby
making supplementation a safe and effective option for treating hyperhomocysteinemia.
However, high concentrations of folate may mask the symptoms of vitamin B12
deficiency, thus potentially leading to pernicious anemia. Current studies are focusing on
whether supplementation therapy will reduce the risk of developing cardiovascular