Background: Acute excess iodine intake can damage the thyroid, but the effects of chronic excess iodine intake are uncertain. Few data exist for pregnant and lactating women and infants exposed to excessive iodine intake. Methods: This was a multicenter cross-sectional study. At study sites in rural Kenya and urban Tanzania previously reporting iodine excess in children, urinary iodine concentration (UIC), thyrotropin, total thyroxine, and thyroglobulin (Tg) were measured in school-age children (SAC), women of reproductive age, pregnant (PW) and lactating women, and breast-feeding and weaning infants. In a national study in Djibouti, UIC was measured in SAC and PW. At all sites, daily iodine intake was estimated based on UIC, and iodine concentration was measured in household salt and drinking water. Results: The total sample size was 4636: 1390, 2048, and 1198 subjects from Kenya, Tanzania, and Djibouti, respectively. In Kenya and Tanzania: (i) median UIC was well above thresholds for adequate iodine nutrition in all groups and exceeded the threshold for excess iodine intake in SAC; (ii) iodine concentrations >40 mg of iodine/kg were found in approximately 55% of household salt samples; (iii) iodine concentrations ≥10 μg/L were detected in 9% of drinking water samples; (iv) Tg was elevated in all population groups, but the prevalence of thyroid disorders was negligible, except that 5–12% of women of reproductive age had subclinical hyperthyroidism and 10–15% of PW were hypothyroxinemic. In Djibouti: (i) the median UIC was 335 μg/L (interquartile range [IQR] = 216–493 μg/L) in SAC and 265 μg/L (IQR = 168–449 μg/L) in PW; (ii) only 1.6% of Djibouti salt samples ( n = 1200) were adequately iodized (>15 mg/kg); (iii) the median iodine concentration in drinking water was 92 μg/L (IQR = 37–158 μg/L; n = 77). In all countries, UIC was not significantly correlated with salt or water iodine concentrations. Conclusions: Although iodine intake was excessive and Tg concentrations were elevated, there was little impact on thyroid function. Chronic excess iodine intake thus appears to be well tolerated by women, infants, and children. However, such high iodine intake is unnecessary and should be avoided. Careful evaluation of contributions from both iodized salt and groundwater iodine is recommended before any review of iodization policy is considered.

Recently, aflatoxin exposure especially through maize and groundnuts has been associated with growth impairment in children. Infants and children are considered to be more susceptible to toxins because of their lower body weight, higher metabolic rate, and lower ability to detoxify. On the other hand, for women of reproductive age, aflatoxin exposure may not only affect their health but also that of their foetus in the case of pregnancy. This study focused on investigating AFB₁ contamination in maize and groundnut from respondent households, exposure among women of reproductive age and associations of aflatoxin contamination with growth retardation among children in Mtwara region, Tanzania. The highest maximum AFB₁ contamination levels from all samples obtained were in maize grain (2351.5 μg/kg). From a total of 217 maize samples collected, aflatoxins were above European Union (EU) and East African Community (EAC) tolerable limits in 76.0% and 64.5% of all samples. Specifically, maize grain had the highest proportion of samples contaminated above tolerable limits (80.3% and 71.1% for EU and EAC limits). Groundnut had 54.0% and 37.9% of samples above EU and EAC maximum tolerable limits. The lowest proportion of contaminated samples on the other hand was for bambara nut (37.5% and 29.2% for EU and EAC limits, respectively). Aflatoxin exposure in our surveyed population was much higher than previous observations made in Tanzania and also higher than those observed in Western countries such as Australia and the USA. Among children, AFB₁ concentration was associated with lower weight for height z scores and weight for age z scores in the univariate model (p < 0.05). In summary, these results indicate the seriousness of aflatoxin contamination in foods commonly consumed in the vulnerable population assessed. Strategies both from the health, trade, and nutrition sectors should therefore be designed and implemented to address aflatoxin and mycotoxin contamination in diets.

Large genome-wide association (GWA) studies of European ancestry individuals have identified multiple genetic variants influencing iron status. Studies on the generalizability of these associations to African ancestry populations have been limited. These studies are important given interethnic differences in iron status and the disproportionate burden of iron deficiency among African ancestry populations. We tested the associations of 20 previously identified iron status-associated single nucleotide polymorphisms (SNPs) in 628 Kenyans, 609 Tanzanians, 608 South Africans and 228 African Americans. In each study, we examined the associations present between 20 SNPs with ferritin and haemoglobin, adjusting for age, sex and CRP levels. In the meta analysis including all 4 African ancestry cohorts, we replicated previously reported associations with lowered haemoglobin concentrations for rs2413450 (β = -0.19, P = 0.02) and rs4820268 (β = -0.16, P = 0.04) in TMPRSS6. An association with increased ferritin concentrations was also confirmed for rs1867504 in TF (β = 1.04, P = <0.0001) in the meta analysis including the African cohorts only. In all meta analyses, we only replicated 4 of the 20 single nucleotide polymorphisms reported to be associated with iron status in large GWA studies of European ancestry individuals. While there is now evidence for the associations of a number of genetic variants with iron status in both European and African ancestry populations, the considerable lack of concordance highlights the importance of continued ancestry-specific studies to elucidate the genetic underpinnings of iron status in ethnically diverse populations.

Despite the severity of food insecurity in Afghanistan, little is known about the factors contributing to household food insecurity (HFI) under the Taliban regime. Therefore, this paper investigated the social determinants of severe HFI in rural areas of Afghanistan. We used the fifth-round survey of 6019 rural households from 25 provinces, collected between July and August 2022 by the Food and Agriculture Organization. We used binary logistic regression to examine the association between household characteristics and HFI. The majority of household heads were male (97.8%) with no education (62.8%). The findings showed that female-headed households had significantly higher odds of severe HFI. Household heads with any level of formal education had significantly reduced odds of severe HFI, while the odds of severe HFI was not different among those with religious/informal household-head education compared to those with no education. Likewise, engagement in any type of agricultural activity decreased the odds of severe HFI. Additionally, household income per member was negatively, while household size was positively associated with severe HFI. In summary, interventions to alleviate HFI among rural households should prioritize income-generating opportunities and skills targeting households with female heads, low levels of household-head education, larger size, no agricultural activities, and low income.

Background: It is unknown whether single nucleotide polymorphisms (SNPs), associated with iron status in European and Asian populations, have the same