A Cross-Sectional Study of the Associations between Biomarkers of Vitamin D, Iron Status, and Hemoglobin in South African Women of Reproductive Age: the Healthy Life Trajectories Initiative, South Africa

• Published in: Current developments in nutrition 2023-05, Vol.7 (5), p.100072, Article 100072
• Main Authors: Soepnel, Larske M., Mabetha, Khuthala, Draper, Catherine E., Silubonde, Takana Mary, Smuts, Cornelius M., Pettifor, John M., Norris, Shane A.
• Format: Article
• Language: English
• Subjects: anemia; fat mass index; hemoglobin; iron deficiency; Original Research; vitamin D; women of reproductive age
• ISSN: 2475-2991; 2475-2991
• DOI: 10.1016/j.cdnut.2023.100072

Vitamin D deficiency and anemia impact the health of women of reproductive age. Evidence suggests an inverse relationship between serum vitamin D (25-hydroxyvitamin D [25(OH)D]) and anemia/iron deficiency, but less is known about these associations in women of reproductive age, in particular in a setting with a combined burden of micronutrient deficiency, food insecurity, and obesity. We aimed to assess the associations between 25(OH)D and biomarkers of iron and anemia in a cohort of women of reproductive age from Soweto, South Africa. The prevalence of vitamin D deficiency was also assessed. In this cross-sectional substudy of the Healthy Life Trajectories Initiative (HeLTI) South Africa pilot trial, 25(OH)D, iron markers (ferritin and soluble transferrin receptor [sTFR]), and altitude-adjusted hemoglobin (Hb) were measured in 493 women aged 18 to 25 years. Associations between iron deficiency/anemia and vitamin D status were evaluated using multivariable logistic regression, adjusting for confounders including fat mass index (FMI). Structural equation modeling (SEM) was performed to evaluate direct and indirect pathways between 25(OH)D, iron and anemia markers, and covariates. Of 493 participants, 136 (27.6%) had vitamin D insufficiency (25(OH)D ≥12–20 ng/mL), whereas 28 (5.6%) had vitamin D deficiency (