Determinants of Folate and Vitamin B₁₂ Deficiencies in Women of Reproductive Age: Insights from the National Nutrition Survey of Pakistan 2018

Background: Anemia is a severe public health issue, particularly among women of reproductive age (WRA) in low-and middle-income countries. Pakistan National Nutrition Survey (NNS) 2011 showed a high prevalence of B12 and folate deficiency in WRA, necessitating further investigation in follow-up surveys. Methods: Using a stratified multi-stage sampling technique, we conducted a secondary analysis of the National Nutrition Survey (NNS) 2018–2019. Blood samples were collected from 31,828 WRA (15–49 years old), and a subsample was examined for folate (n=12662) and B12 deficiencies (n=4442). B12 and folate levels were measured using Electrochemiluminescence immunoassay and a CDC-approved microbiologic assay, respectively. The association of factors was analyzed using logistic regression. Results: 44.7% and 20.2% WRA had folate and B12 deficiency, respectively. Provincial distribution was associated with folate deficiency i.e., Sindh OR=1.140 (95% CI 1.018, 1.285), Baluchistan OR = 1.237 (95% CI 1.052, 1.453), Islamabad OR = 1.524 (95% CI 1.109, 2.092). In comparison, B12 deficiency was prevalent in Islamabad, OR = 1.673 (95% CI 1.122, 2.497), Gilgit Baltistan, OR = 2.472 (95% CI 1.197, 5.106), and the tribal districts of KPK, OR = 1.584 (95% CI 0.977, 2.570). Rural residence OR=1.407 (95% CI 1.125, 1.760), being obese OR=1.649 (95% CI 1.282, 2.122), and being overweight OR=1.560 (95% CI 1.262, 1.928) were also associated with B12 deficiency. Conclusion: Study revealed that nearly half of women were affected by folate deficiency and one in five by B12 deficiency. The findings highlight significant regional disparities and stronger vulnerability among women in rural areas and those with higher body mass indices. These results emphasize the need for targeted nutritional interventions, improved dietary diversity, and public health strategies.