Antioxidant vitamins in malnourished Nigerian children.

The antioxidant capacity in malnutrition--as far as it is related to vitamins--was studied by determining the plasma concentrations of the most prominent antioxidant vitamins (retinol, tocopherols, carotenoids, cryptoxanthine, lycopene, and ubiquinone-10) in marasmic (M; n = 15), severe marasmic (SM; n = 8), kwashiorkor (KW; n = 12), and normally nourished (CO; n = 18) children in Nigeria. Retinol was found to be reduced in severe marasmic children when compared to local controls (medians and interquartile ranges; SM: 155 micrograms/l, 117-178 micrograms/l; CO: 281 micrograms/l 209-413 micrograms/l; p < 0.005). A strong correlation between plasma retinol and retinol binding protein could be found in all groups (SM: r = 0.79; M: r = 0.93; KW: r = 0.80; CO: r = 0.70). The tocopherol/lipid-ratio was lowered in kwashiorkor (median 0.48 mg/g, interquartile range 0.41-0.66 mg/g). A sufficient tocopherol status was only found in one child with kwashiorkor. alpha-Carotene, beta-carotene, cryptoxanthine and lycopene were below the detection limits in most of the malnourished children. Plasma ubiquinone-10 was significantly higher in kwashiorkor (median 1.05 micrograms/ml, interquartile range 0.88-1.17 micrograms/ml) than in all other groups (CO: 0.71 micrograms/ml, 0.55-0.99 micrograms/ml: M: 0.72 micrograms/ml, 0.65-0.83 micrograms/ml; SM: 0.89 micrograms/ml, 0.61-0.83 micrograms/ml). It is concluded that a depletion of antioxidant vitamins is present in malnourished Nigerian children, especially pronounced in the kwashiorkor syndrome. The mechanisms leading to elevated plasma ubiquinone-10 in kwashiorkor require further studies.