**5. Treatment of hyperhomocysteinemia**

The treatment of hyperhomocysteinemia varies with the underlying cause.

In the case of deficiency of one or more vitamins involved in homocysteine metabolism, blood levels of this amino acid are often elevated well above those observed in the healthy population. Treatment of hyperhomocysteinemia includes supplementation with mostly pharmacological doses of one or more of the relevant B vitamins and is generally effective in reducing homocysteine concentrations and delays atherosclerotic and thrombotic events.

The negative impact of particular genotypes on homocysteine levels can partly be compensated by folate intake and is, even in smaller part, dependent on several other variables that affect homocysteine levels (see Table 2). For example, if persons have balanced diet with optimal intake of B6 and B12 vitamins and folates it seems that the C677T mutation and the subsequent reduced activity of the enzyme MTHFR do not connect with hyperhomocysteinemia (Schriver et al., 1995; Silaste et al., 2001). Besides, folic acid supplemetation reduces the plasma homocysteine concentration in all three genotypes (TT, CT and CC) of the MTHFR C677T mutation (Meshkin & Blum, 2007).

This scientific evidence suggests that the MTHFR C677T genetic mutation influences folate metabolism, leading to the conclusion that dietary intake of a standard dosage of folate may be insufficient for half to two-thirds of the population with this mutation (Meshkin & Blum, 2007).

In the case of CBS deficiency, the enzyme activity can effectively be enhanced by treatment with large doses of vitamin B6.

A combination of all three relevant coenzymes to treat milder forms of hyperhomocysteinemia resulted in a clear 50% reduction of plasma homocysteine levels. However, given alone, only folic acid was able to induce similar reductions, whereas vitamin B 12 was little effective and vitamin B6 failed to show an effect (Perry et al., 1968, Ubbink et al., 1993; Ubbink et al., 1994).

Many countries have implemented mandatory folic acid fortification of flour and grain products to reduce the risk of various diseases. Besides, individuals can find a good source of folate in fruits and vegetables (especially green leafy vegetables).
