Salt Used for the National School Nutrition Program (NSNP) in Rural Schools of Limpopo Province, South Africa, has Adequate Levels of Iodine.

BACKGROUND: Salt iodisation is considered the most effective long-term public health intervention for achieving optimal iodine nutrition. Effective salt iodisation is a prerequisite for the sustainable elimination of iodine deficiency disorders. The aim of this study was to determine iodine concentration of salt used for the National School Nutrition Program (NSNP). METHODS: A cross-sectional study was conducted in 359 food handlers from Vhembe and Mopani districts of Limpopo Province, South Africa. The questionnaire was administered to solicit data on demographic information, general questions on salt fortification, and iodine nutrition knowledge. After the interviews, two tablespoons of salt used for the NSNP food preparation was collected from 318 schools in small zip-lock plastic bags. The salt samples were coded and stored at room temperature and protected from light and moisture until the time of analysis. Salt iodine concentrations were determined at the North-West University (NWU) in Potchefstroom by means of the iCheck test method. RESULTS: The median iodine concentration of both Mopani (31.65 ppm) and Vhembe (32.56 ppm) districts signified adequate iodine levels. Of 318 salt samples, 113 (71%) samples in Mopani and 104 (65%) in Vhembe had an iodine concentration of 15-64 ppm. A few (6%) food handlers in Mopani and almost half (45.9%) in Vhembe could correctly identify iodated salt as the main source of iodine. Almost half of the food handlers (%) in Mopani and 36.5% in Vhembe did not know which part of body needs iodine for functioning. CONCLUSION: More than 20 years after the implementation of the USI program, the result of the study shows that the international goal of 90% coverage is still far from being realised.

Dried Blood Spot Thyroglobulin as a Biomarker of Iodine Status in Pregnant Women.

Context: Thyroglobulin (Tg) could be a sensitive biomarker of iodine nutrition in pregnant women (PW). A dried blood spot (DBS) assay would simplify collection and transport in field studies. Objectives: Our aims were to (1) establish and test a reference range for DBS-Tg in PW; (2) determine whether co-measurement of Tg antibodies (Abs) is necessary to define population iodine status. Design, Setting, and Participants: Standardized cross-sectional studies of 3870 PW from 11 countries. For the DBS-Tg reference range, we included TgAb-negative PW (n = 599) from 3 countries with sufficient iodine intake. Main Outcome Measures: We measured the urinary iodine concentration and DBS thyroid-stimulating hormone, total thyroxin, Tg, and TgAb. Results: In the reference population, the median DBS-Tg was 9.2 µg/L (95% confidence interval, 8.7 to 9.8 µg/L) and was not significantly different among trimesters. The reference range was 0.3 to 43.5 µg/L. Over a range of iodine intake, the Tg concentrations were U-shaped. Within countries, the median DBS-Tg and the presence of elevated DBS-Tg did not differ significantly between all PW and PW who were TgAb-negative. Conclusions: A median DBS-Tg of ∼10 µg/L with <3% of values ≥44 µg/L indicated population iodine sufficiency. Concurrent measurement of TgAb did not appear necessary to assess the population iodine status.

Knowledge and practices of pre-school teachers on growth monitoring program--South Africa.

The aim of this study was to determine knowledge and practices of pre-school teachers on growth monitoring. A quasi-experimental, one-group pre- and post-test intervention study was conducted in eight conveniently selected government subsidized pre-schools in Vhembe and Mopani districts of Limpopo Province, South Africa. Fifteen pre-school teachers participated in the study. An intervention in a form of nutrition education lessons on growth monitoring was developed and implemented. Pre-school teachers completed a knowledge test questionnaire prior to the lessons. The intervention also included the following training skills: procedure to take anthropometric measurements and plotting the Road to Health Chart. About 67% teachers understood the importance of growth monitoring at baseline. The results also showed an improvement 6 months after intervention. All (100%) teachers knew that growth monitoring can be used for diagnosing undernutrition. The results also showed an improvement in skills, such as the procedure to take anthropometric measurements. Knowledge and practices of teachers on growth monitoring were improved by nutrition education 6 months after intervention.

Vitamin A supplementation in iodine-deficient African children decreases thyrotropin stimulation of the thyroid and reduces the goiter rate.

BACKGROUND: Vitamin A (VA) deficiency (VAD) and iodine deficiency (ID) often coexist in children in Africa. VAD may affect thyroid function and the response to iodine prophylaxis. OBJECTIVE: The aim was to investigate the effects of supplementation with iodine or VA alone, and in combination, in children with concurrent VAD and ID. DESIGN: A 6-mo randomized, double-blind, 2 x 2 intervention trial was conducted in 5-14 y-old South African children (n = 404), who, on average, had mild-to-moderate VAD and ID. At baseline and after 3 mo, children received 1) iodine (191 mg I as oral iodized oil) + placebo (IS group), 2) VA (200000 IU VA as retinyl palmitate) + placebo (VAS group), 3) both iodine and VA (IS+VAS group), or 4) placebo. At baseline, 3 mo, and 6 mo, urinary iodine (UI), thyroid volume, thyrotropin (thyroid-stimulating hormone; TSH), total thyroxine (TT(4)), thyroglobulin, serum retinol (SR), and retinol-binding protein (RBP) were measured. RESULTS: SR and RBP increased significantly with VA supplementation (P < 0.05). For UI, SR, and RBP, there were no significant treatment interactions between iodine and vitamin A. The 3-factor and all three 2-factor interactions were significant for thyroid volume, TSH, and thyroglobulin (P < 0.001), whereas none of these interactions were significant for TT(4). There was a clear effect of VAS without IS on TSH, thyroglobulin, and thyroid volume; all 3 variables decreased significantly (P < 0.05). CONCLUSIONS: Iodine prophylaxis is effective in controlling ID in areas of poor vitamin A status. VA supplements are effective in treating VAD in areas of mild ID and have an additional benefit-through suppression of the pituitary TSHbeta gene, VAS can decrease excess TSH stimulation of the thyroid and thereby reduce the risk of goiter and its sequelae.

Treatment of iodine deficiency in school-age children increases insulin-like growth factor (IGF)-I and IGF binding protein-3 concentrations and improves somatic growth.

CONTEXT: Iodine deficiency in utero impairs fetal growth, but the relationship between iodine deficiency and postnatal growth is less clear. OBJECTIVE: The objective of the study was to determine whether iodine repletion improves somatic growth in iodine-deficient children and investigate the role of IGF-I and IGF binding protein (IGFBP)-3 in this effect. DESIGN, PARTICIPANTS, AND INTERVENTIONS: Three prospective, double-blind intervention studies were done: 1) in a 10-month study, severely iodine-deficient, 7- to 10-yr-old Moroccan children (n = 71) were provided iodized salt and compared with children not using iodized salt; 2) in a 6-month study, moderately iodine-deficient, 10- to 12-yr-old Albanian children (n = 310) were given 400 mg iodine as oral iodized oil or placebo; 3) in a 6-month study, mildly iodine-deficient 5- to 14-yr-old South African children (n = 188) were given two doses of 200 mg iodine as oral iodized oil or placebo. At baseline and follow-up, height, weight, urinary iodine (UI), total T4 (TT4), TSH, and IGF-I were measured; in Albania and South Africa, IGFBP-3 was also measured. RESULTS: In all three studies, iodine treatment increased median UI to more than 100 microg/liter, whereas median UI in the controls remained unchanged. In South Africa, iodine repletion modestly increased IGF-I but did not have a significant effect on IGFBP-3, TT4, or growth. In Albania and Morocco, iodine repletion significantly increased TT4, IGF-I, IGFBP-3, weight-for-age z scores, and height-for-age z scores. CONCLUSION: This is the first controlled study to clearly demonstrate that iodine repletion in school-age children increases IGF-I and IGFBP-3 concentrations and improves somatic growth.