title: Iodine status and associations with feeding practices and psychomotor milestone development in six-month-old South African infants.
abstract: Iodine is important for normal growth and psychomotor development. While infants below 6 months of age receive iodine from breast milk or fortified infant formula, the introduction of complementary foods poses a serious risk for deteriorating iodine status. This cross-sectional analysis assessed the iodine status of six-month-old South African infants and explored its associations with feeding practices and psychomotor milestone development. Iodine concentrations were measured in infant (n = 386) and maternal (n = 371) urine (urinary iodine concentration [UIC]), and in breast milk (n = 257 [breast milk iodine concentrations]). Feeding practices and psychomotor milestone development were assessed in all infants. The median (25th-75th percentile) UIC in infants was 345 (213-596) μg/L and was significantly lower in stunted (302 [195-504] μg/L) than non-stunted (366 [225-641] μg/L) infants. Only 6.7% of infants were deficient. Maternal UIC (128 [81-216] μg/L; rs= 0.218, p < 0.001) and breast milk iodine concentrations (170 [110-270] μg/kg; rs= 0.447, p < 0.0001) were associated with infant UIC. Most infants (72%) were breastfed and tended to have higher UIC than non-breastfed infants (p = 0.074). Almost all infants (95%) consumed semi-solid or solid foods, with commercial infant cereals (60%) and jarred infant foods (20%) being the most common solid foods first introduced. Infants who reported to consume commercial infant cereals ≥4 days weekly had significantly higher UIC (372 [225-637] μg/L) than those reported to consume commercial infant cereals seldom or never (308 [200-517] μg/L; p = 0.023). No associations between infant UIC and psychomotor developmental scores were observed. Our results suggest that iodine intake in the studied six-month-old infants was adequate. Iodine in breast milk and commercial infant cereals potentially contributed to this adequate intake.
authors.affiliation: Centre of Excellence for Nutrition, North-West University, Potchefstroom, South Africa.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Osei
authors.affiliation: Centre of Excellence for Nutrition, North-West University, Potchefstroom, South Africa.
authors.forename: Jeannine
authors.initials: J
authors.lastname: Baumgartner
authors.affiliation: Centre of Excellence for Nutrition, North-West University, Potchefstroom, South Africa.
authors.forename: Marinel
authors.initials: M
authors.lastname: Rothman
authors.affiliation: Centre of Excellence for Nutrition, North-West University, Potchefstroom, South Africa.
authors.forename: Tonderayi M
authors.initials: TM
authors.lastname: Matsungo
authors.affiliation: Poverty, Health & Nutrition Division, International Food Policy Research Institute, Washington, District of Columbia, USA.
authors.forename: Namukolo
authors.initials: N
authors.lastname: Covic
authors.affiliation: Non-Communicable Disease Research Unit, South African Medical Research Council, Cape Town, South Africa.
authors.forename: Mieke
authors.initials: M
authors.lastname: Faber
authors.affiliation: Centre of Excellence for Nutrition, North-West University, Potchefstroom, South Africa.
authors.forename: Cornelius M
authors.initials: CM
authors.lastname: Smuts
mesh_terms: D001942:Breast Feeding; D003430:Cross-Sectional Studies; D005247:Feeding Behavior; D005260:Female; D006130:Growth Disorders / Q000453:epidemiology / Q000652:urine; D006801:Humans; D007223:Infant; D041943:Infant Formula / Q000737:chemistry; D007455:Iodine / Q000008:administration & dosage / Q000172:deficiency / Q000652:urine*; D008297:Male; D008895:Milk, Human / Q000737:chemistry; D009752:Nutritional Status; D015995:Prevalence; D011597:Psychomotor Performance / Q000187:drug effects*; D018401:Sample Size; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage; D013019:South Africa / Q000453:epidemiology
chemical_list: D017673:Sodium Chloride, Dietary; C034024:iodized salt; D007455:Iodine
keywords: commercial infant cereals; complementary feeding practices; iodine status; psychomotor milestone development; weaning infants