Vitamin B-12, vitamin B-6, and folate nutritional status in men with hyperhomocysteinemia

Abstract

We measured the vitamin B-6, vitamin B-12, and folic acid nutritional status in a group of apparently healthy men (n = 44) with moderate hyperhomocysteinemia (plasma homocysteine concentration > 16.3 mumol/L). Compared with control subjects (n = 274) with normal plasma homocysteine (< or = 16.3 mumol/L) concentrations, significantly lower plasma concentrations of pyridoxal-5'-phosphate (P < 0.001), cobalamin (P < 0.001), and folic acid (P = 0.004) were demonstrated in hyperhomocysteinemic men. The prevalence of suboptimal vitamin B-6, B-12, and folate status in men with hyperhomocysteinemia was 25.0%, 56.8%, and 59.1%, respectively. In a placebo-controlled follow-up study, a daily vitamin supplement (10 mg pyridoxal, 1.0 mg folic acid, 0.4 mg cyanocobalamin) normalized elevated plasma homocysteine concentrations within 6 wk. Because hyperhomocysteinemia is implicated as a risk factor for premature occlusive vascular disease, appropriate vitamin therapy may be both efficient and cost-effective to control elevated plasma homocysteine concentrations.

Folate intake in Europe: recommended, actual and desired intake

“…Using a daily combined vitamin supplement containing 1000 mg folic acid, 12.2 mg vitamin B 6 , and 0.4 mg vitamin B 12 for six weeks in mild hyperhomocysteinemic men, demonstrated that high plasma homocysteine levels can be normalised. Doubling the vitamin doses for two weeks did not result in a further decrease in homocysteine levels (Ubbink et al, 1993a). Using the combined supplement (1000 mg folic acid, 12.2 mg vitamin B 6 , and 0.4 mg vitamin B 12 ), Ubbink and co-workers showed that some mild hyperhomocysteinemic men require only temporary vitamin supplementation to obtain long-term normal plasma homocysteine levels: after 6 weeks of vitamin intervention the advice to include more folate-rich foods in the diet was suf®cient to maintain normal plasma homocysteine levels (`16.3 mmol/L) for at least 48 weeks.…”

“…Reported normal plasma values in healthy blood donors ranged from 7.9±9.3 mmol/L (Green & Jacobsen, 1995). Values b16.3 mmol/L are commonly considered indicative of milk hyperhomocysteinemia (Ubbink et al, 1993a(Ubbink et al, , 1993b(Ubbink et al, , 1994, although others have used levels b13.6 mmol/L (Hall & Chu, 1990), b14 mmol/L (Selhub et al, 1993), and b15 mmol/L (Genest et al, 1991).…”

“…There is now solid evidence that folic acid supplementation during the periconceptional period significantly reduces the risk of giving birth to a child with a neural tube defect (NTD) (MRC, 1991;Czeizel & Duda Âs, 1992). More recent ®ndings indicate that supplementation with folic acid decreases plasma homocysteine levels (Brattstro Èm et al, 1988;Ubbink et al, 1993aUbbink et al, , 1993bUbbink et al, , 1994. This a signi®cant ®nding, since elevated plasma homocysteine levels are found to be an independent risk factor for vascular diseases (Boushey et al, 1995).…”

Serum folate, homocysteine and colorectal cancer risk in women: a nested case–control study

“…To compensate for the lack of red-cell specimens in our study, we measured serum homocysteine, which has been proposed as a sensitive indicator of functional folate deficiency that is distinguishable from low serum folate concentrations following shortterm decreases in dietary intake (Kang et al, 1987;Stabler et al, 1988;Ubbink et al, 1993;Jacob et al, 1994;O'Keefe et al, 1995). Our data show that the variability of serum homocysteine in the population was much narrower than that of folate, suggesting that homocysteine levels are more tightly regulated by metabolism.…”

Diet, an independent determinant for plasma total homocysteine. A cross sectional study of Norwegian workers on platforms in the North Sea

“…Low levels of the vitamins folate, cobalamin and B-6 have been shown to be related to elevated levels of tHcy (Ubbink et al, 1993;Selhub et al, 1993). Coffee and nonnutritional factors such as cigarette smoking and exercise have also been shown to be associated with the tHcy level (Nyga Êrd et al, 1995;Nyga Êrd et al, 1997b) in a dose dependent manner, and we have recently observed that smoking, coffee drinking and low vitamin intake are associated with both an increase in mean tHcy level as well as a more skew tHcy distribution (Nyga Êrd, 1997c), suggesting that lifestyle factors may be important determinants of the tHcy level.…”