Vitamin B2, vitamin B12 and total homocysteine status in children and their associations with dietary intake of B-vitamins from different food groups: the Healthy Growth Study

To examine the associations between the dietary intakes of certain B-vitamins from different food sources with the relevant plasma status indices in children. A representative subsample of 600 children aged 9-13 years from the Healthy Growth Study was selected. Dietary intakes of vitamins B-2, B-12, B-6 and folate derived from different food sources were estimated. Plasma levels of vitamin B-2 (or riboflavin), methylmalonic acid (MMA) and total homocysteine (tHcy) were also measured. Plasma concentrations of vitamin B-2 below 3 mu g/L were found in 22.8 % of the children. Children in the lower quartile of dietary vitamin B-2 intake were found to have the lowest plasma vitamin B-2 levels compared to children in the upper three quartiles (5.06 +/- 7.63 vs. 6.48 +/- 7.88, 6.34 +/- 7.63 and 6.05 +/- 4.94 mu g/L respectively; P = 0.003). Regarding vitamin B-12 children in the lower quartile of dietary intake had higher mean plasma tHcy levels compared to children in the upper two quartiles, respectively (6.00 +/- 1.79 vs. 5.41 +/- 1.43 and 5.46 +/- 1.64 mu mol/L; P = 0.012). Positive linear associations were observed between plasma vitamin B-2 levels and dietary vitamin B-2 derived from milk and fruits (beta = 0.133; P = 0.001 and beta = 0.086; P = 0.037). Additionally, nonlinear associations were also observed between plasma vitamin B-2 levels and vitamin B-2 derived from red meat, as well as between tHcy levels and vitamins B-12 and B-6 derived from milk; vitamins B-12, B-6 and folate derived from cereal products and folate derived from fruits. A considerably high prevalence of poor plasma vitamin B-2 status was observed in children. The intake of milk, fruits and cereals was associated with more favorable tHcy levels, while the intake of milk and fruits with more favorable plasma B2 levels. However, these findings need to be further confirmed from controlled dietary intervention studies examining the modulation of biomarkers of B-vitamins.