Stunting in school-age years may result in a decrease in adult size, and thus reduced work capacity and adverse reproductive outcomes. We have compared the mean intakes of energy, protein and selected growth-limiting nutrients in fifty-eight stunted children and 172 non-stunted controls drawn from 567 children aged 6 -13 years attending ten rural schools in NE Thailand. Control children were selected randomly after stratifying children by age in each school. Dietary data were calculated from 24-h recalls using nutrient values from Thai food composition data and chemical analysis. Inter-relationships between stunting and sociodemographic, anthropometric and biochemical variables were also examined. Biochemical variables investigated were serum albumin, zinc, ferritin, transferrin receptor and retinol, and iodine in casual urine samples. Significantly more males than females were stunted (males, n 38, 65·5 % v. females, n 20, 34·5 %; P¼ 0·025). Stunted males had lower mean intakes of energy, protein, calcium, phosphorus and zinc, and a lower mean (95 % CI) serum zinc (9·19 (8·53, 9·84) v. 9·70 (8·53, 9·29) mmol/l) than non-stunted males; no other biochemical differences were noted. Stunted males also had a lower mean arm muscle area (P¼0·015), after adjusting for age, than nonstunted males. In conclusion, the lower dietary intakes of the stunted males compared to their non-stunted counterparts may be associated with anorexia and hypogeusia induced by zinc deficiency. Hence, zinc deficiency may be a factor limiting linear growth, especially among boys in NE Thailand, but more research is needed to establish whether other factors also play a role.

L-selenomethionine (SeMet) and sodium selenite are widely used selenium nutritional supplements with potential benefit in preventing cancer. However, supplementation is not without risks of toxicity if intake is too high. The aim of the present study was to investigate SeMet and selenite metabolism in the gastrointestinal tract with particular focus on the formation of the volatile selenium excretion products, dimethylselenide (DMSe) and dimethyldiselenide (DMDSe). Adult male Wistar rats (n = 5) were euthanized, their intestinal tracts removed and the contents of jejunum, ileum, caecum and colon used to prepare 10% suspensions in saline. SeMet and selenite (0.5-0.6 mM) were then incubated with these suspensions at 37°C for 3 h. Caecum and colon contents were the most metabolically active towards SeMet with 30% and 15% metabolized over 3 h. DMDSe was the only volatile selenium metabolite detected accounting for 8.7 ± 1.3% of the selenium lost in caecum contents. Selenite was completely metabolized by caecum contents and 73% by colon contents under the same conditions forming DMSe (5.7 ± 0.9% of the selenium lost in caecum) and a precipitate of red amorphous elemental selenium. Based on previous literature and these results, we conclude that the gut microbiota contributes to the excretion of excess selenium through the production of methylated selenium compounds and elemental selenium.

Poor mixing at the T-connection appears to be the cause of delayed and/or incomplete gentamicin delivery for low dose volumes and slow infusion rates.

Selenomethionine (SeMet) is a widely used nutritional supplement that has potential benefit for people living in selenium-deficient areas. Previous research has shown that selenium administered as SeMet undergoes significant enterohepatic recycling which may involve the gut microflora. In order to investigate this we have developed a simple method for the quantitation of l-SeMet in rat gut content suspensions prepared from jejunum, ileum, caecum and colon. After incubation of l-SeMet with gut content suspensions, samples were deproteinized with sulfosalicylic acid and derivatized with o-phthaldialdehyde (OPA) and N-acetyl-l-cysteine (NAC). Mass spectrometry confirmed the formation of a 1:1:1 derivative of l-SeMet with OPA and NAC. Samples were analysed by reversed-phase high-performance liquid chromatography with fluorescence detection. The assay was linear in the concentration range 0.5-100 microg/mL (r(2) = 0.9992) with a limit of detection of 0.025 microg/mL (signal-to-noise ratio of 5). Intra-day and inter-day accuracies were 91.1-92.8 and 91.7-95.5%, respectively with corresponding precisions as relative standard deviation of <5%. Incubation of l-SeMet with gut content suspensions from different parts of the rat intestine showed that l-SeMet metabolism occurs mainly in the caecum.

Phytate, a salt of phytic acid (myo-inositol 1,2,3,4,5,6-hexakisphosphate), is found in certain plant-based foods. It strongly chelates minerals, forming insoluble complexes in the small intestine that cannot be digested or absorbed. Information on the phytate content of rice-based diets of children in Northeast Thailand is limited. In this study 1-day weighed duplicate diet composites were collected from 40 Northeast Thai children (age 6-13 years) randomly selected from participants (n=567) of an efficacy trial in Ubon Ratchathani province. Diet composites were analyzed for zinc, iron, and calcium by atomic absorption spectrophotometry, and for phytate (as inositol penta-phosphate and hexa-phosphate) by high-performance liquid chromatography; the accuracy and precision were established using a certified reference material for the minerals and an inter-laboratory comparison for phytate. The median (1st, 3rd quartiles) zinc, iron, and calcium contents of the diet composites were 4.3 (3.7, 6.1), 4.3 (3.2, 6.5) and 130 (82, 216) mg/day, respectively. The inositol penta-phosphate and hexa-phosphate levels were so low they were below the detection limit, attributed in part to leaching of water-soluble potassium and magnesium phytate from glutinous rice after soaking overnight before cooking. Clearly, phytate will not compromise mineral absorption from these diets. Instead, low zinc intakes are probably primarily responsible for the low zinc status of these children. In contrast, although intakes of dietary iron appear low, the prevalence of biochemical iron deficiency was also low, suggesting that iron absorption may have been higher than previously assumed. Whether the low calcium intakes compromise optimal bone health in these growing Northeast Thai school children is unknown.