Polyunsaturated Fatty Acid Plasma Content in Groups of General Population with lowvitamin B6 or low iron serum levels

Experimental and human studies describe the adverse effect of iron or vitamin B6 deficiencies on polyunsaturated fatty acid metabolism. Iron is present in end proteins of the delta6-desaturase enzyme complex, and vitamin B6 deficiency can affect the transmethylation reaction of proteins. Plasma polyunsaturated fatty acid content was estimated in apparently healthy subjects of the general population with no consumption of fish and low vitamin B6 serum levels (< 3 microg/l; n = 21) or with low iron serum levels (men: < 12 micromol/l; women: < 10 micromol/l; n = 16) and compared to a control group (n = 22) with normal vitamin B6 and iron serum levels (in reference range). The activities of the delta6-desaturase enzyme complex were calculated as product/precursor (conversion indices). In groups of subjects with low vitamin B6 and low iron levels, delta6-desaturase activity together with delta5-desaturase activity (conversion of alpha-linolenic/18:3,n-3/ into eicosapentaenoic acid/20:5,n-3/) as well as the conversion index of docosahexaenoic acid formation (22:6,n-3) from 22:5,n-3 (second delta6-desaturase activity) were significantly reduced. The inhibition effect on fatty acid synthesis was more pronounced in subjects with low iron levels than in those with low vitamin B6 levels. The conversion indices correlated significantly positively with vitamin B6 or iron levels.