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 B₂, B₁₂, B₆ and folate derived from different food sources were estimated. Plasma levels of vitamin B₂ (or riboflavin), methylmalonic acid (MMA) and total homocysteine (tHcy) were also measured.

Plasma concentrations of vitamin B₂ below 3 μg/L were found in 22.8 % of the children. Children in the lower quartile of dietary vitamin B₂ intake were found to have the lowest plasma vitamin B₂ 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 μg/L respectively; P = 0.003). Regarding vitamin B₁₂ 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 μmol/L; P = 0.012). Positive linear associations were observed between plasma vitamin B₂ levels and dietary vitamin B₂ derived from milk and fruits (β = 0.133; P = 0.001 and β = 0.086; P = 0.037). Additionally, nonlinear associations were also observed between plasma vitamin B₂ levels and vitamin B₂ derived from red meat, as well as between tHcy levels and vitamins B₁₂ and B₆ derived from milk; vitamins B₁₂, B₆ and folate derived from cereal products and folate derived from fruits.

A considerably high prevalence of poor plasma vitamin B₂ 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.