Biochemical Assessment of Folate, VitaminB12 & Thalassemia Gene Prevalence
in Women of Reproductive Age (National Nutrition Survey2011)

Background

Women of reproductive age (1549years) are a pivotal population for publichealth nutrition strategies. Adequate folate and vitaminB12 status reduces the risk of neuraltube defects (NTDs) and other adverse pregnancy outcomes, while carrier status for and thalassemia influences the risk of severe hemoglobinopathies in offspring. The National Nutrition Survey (NNS) 2011 was the first largescale, nationally representative effort to simultaneously assess dietary intake, biochemical markers, and genetic risk factors for these nutrients and disorders.

Objectives of the 2011 Assessment

• Estimate the prevalence of folate deficiency, vitaminB12 deficiency, and borderline status among women aged 1549years.
• Determine the carrier frequencies of and thalassemia genes in the same group.
• Identify sociodemographic and dietary determinants of low status.
• Provide evidence for policymaking on fortification, supplementation, and genetic counseling.

Methodology

The NNS 2011 used a multistage, stratified sampling design covering urban and rural districts. A total of 6,842 women provided blood samples and completed a foodfrequency questionnaire (FFQ). Laboratory analyses were performed in a central certified lab.

Biochemical Measurements

• Serum folate: Measured by chemiluminescent immunoassay. Deficiency defined as < 4ngmL, borderline 46ngmL.
• Serum vitaminB12: Chemiluminescent assay. Deficiency < 200pgmL, borderline 200300pgmL.
• Redcell folate: Used as a longerterm indicator; deficiency < 140ng10RBC.

Genetic Testing

DNA extracted from whole blood was screened for the most common deletions and point mutations using multiplex PCR and reverse dotblot hybridisation. The target mutations were:

• thalassemia: deletion, deletion, and the SEA deletion.
• thalassemia: IVSI5 (G>C), IVSI1 (G>A), and codon41/42 (CTTT).

Data Analysis

Weighted prevalence estimates were calculated to reflect the national population. Logistic regression identified independent predictors of deficiency or carrier status, adjusting for age, education, urban/rural residence, and dietary intake.

Key Findings

Folate Status

Deficiency was highest among women aged 1519years (18%) and those with <8years of formal education (21%). Rural residents had a 1.6fold higher odds of deficiency compared with urban women (OR=1.62; 95%CI1.381.90).

VitaminB12 Status

Low B12 was strongly linked to vegetarian diets (OR=2.3) and low socioeconomic status. Women from the northern provinces showed the highest deficiency rates (14%).

Thalassemia Gene Carriers

The SEA deletion accounted for 68% of thalassemia alleles, while IVSI5 (G>C) was the predominant thalassemia mutation (45%). Carrier frequency peaked in women aged 3034years, reflecting cumulative exposure to regional genetic pools.

Combined NutrientGenetic Risk

Approximately 8% of women were both folatedeficient (or borderline) and carriers of a thalassemia gene, a subgroup that could benefit from targeted preconception counselling and higherdose folic acid supplementation (4mg/day) to reduce NTD risk.

Discussion

The 2011 NNS highlights that, despite overall improvements in nutritional status, significant subpopulations of women of reproductive age remain vulnerable to folate and vitaminB12 deficiencies. The prevalence of folate deficiency (12%) exceeds the World Health Organizations target of <10% for countries undertaking mandatory fortification, suggesting that the voluntary fortification programme in place at the time was insufficient.

VitaminB12 deficiency, while lower than folate deficiency, still affects nearly one in ten women. The strong association with vegetarian diets underscores the need for culturally appropriate education and possibly fortified plantbased foods.

Thalassemia carrier rates are comparable with those reported in neighbouring countries, confirming the publichealth relevance of carrier screening programmes. The observed coexistence of nutrient deficiency and carrier status raises concerns because maternal folate deficiency can exacerbate the risk of severe anemia in fetuses with thalassemiaaffected genotypes.

Policy Implications

• Mandatory folic acid fortification: Introduce a 300gper100g wheatflour fortification standard, coupled with monitoring of plasma folate trends.
• Targeted supplementation: Provide 400g600g daily folic acid tablets to women planning pregnancy, and 5g vitaminB12 for those with low dietary intake.
• Genetic counselling: Expand premarital and preconception carrier screening, especially in highprevalence regions (eastern and southern provinces).
• Nutrition education: Develop communitybased programmes that promote consumption of B12rich foods (e.g., fortified soy, dairy) and folaterich vegetables.

Research Gaps

Further longitudinal studies are needed to assess the impact of fortified foods introduced after 2011 on folate status and NTD incidence. In addition, investigations into the interaction between B12 status and homocysteine levels among thalassemia carriers could clarify the cardiovascular risk profile of this group.

Conclusion

The National Nutrition Survey 2011 provides a comprehensive snapshot of micronutrient deficiencies and thalassemia gene prevalence among women of reproductive age. While the majority of women have adequate folate and vitaminB12 levels, a substantial minority remain at risk, especially in rural, loweducation, and vegetarian subpopulations. Simultaneously, over onethird of women carry or thalassemia genes, creating a layered publichealth challenge.

Addressing these issues requires coordinated strategies: mandatory folic acid fortification, targeted supplementation, expanded carrier screening, and culturally sensitive nutrition education. Implementing these measures will help reduce the incidence of NTDs, improve maternalfetal health, and ultimately contribute to healthier future generations.