Biochemical assessment of the nutritional status of infants, children and adolescents in South Africa (1997–2022): a systematic review

Abstract

Abstract Objective: To conduct a systematic review of the published peer-reviewed articles on the biochemical assessment of nutritional status of South African infants, children and adolescents in 1997–2022. Design: Online databases (Pubmed, CINAHL, EbscoHost and SAePublications) were used to identify thirty-nine papers. Setting: South Africa, 1997–2022. Participants: Infants, children and adolescents. Results: Vitamin A deficiency prevalence was 35–67 % before 2001 and mostly below 16 % after 2008. Anaemia ranged from 5·4 to 75·0 %, with 36–54 % of infants below 1 year being anaemic. Among 0- to 6-year-olds, iron deficiency (ID) was 7·2–39·4 % in rural and 16–41·9 % in urban areas. Zn deficiency remained high, especially among 0- to 6-year-olds, at 39–48 %. Iodine insufficiency (UIC < 100 µg/l) was between 0 and 28·8 %, with excessive levels in two areas. Vitamin D deficiency was 5 % for 11- to 17-year-olds in one urban study but 33–87 % in under 10-week-old infants. The 2005 national survey reported sufficient folate status among 0- to 6-year-olds, and vitamin B12 deficiency was 0–21 %. Low-grade inflammation was between 5 % and 42 % depending on the biomarker and cut-offs. Conclusions: Vitamin A status may have improved meaningfully during the last 25 years in South Africa to below 16 %, and iodine and folate deficiency appears to be low particularly among 0- to 6-year-olds. However, confirmation is needed by a national survey. Anaemia, Fe and Zn deficiencies still pose severe problems, especially among 0- to 6-year-olds. Sufficient data on vitamin D and B12 status are lacking.

Keywords

• Micronutrient deficiencies
• Inflammation
• South Africa
• Infants
• Children
• Adolescents
• Nutritional status biomarkers