Journal of Women Health

ABSTRACT

Background: Vitamin D deficiency during pregnancy represents a critical global health challenge with far-reaching consequences for maternal and fetal health outcomes. Despite India's geographical advantage of receiving abundant sunlight throughout the year, vitamin D deficiency paradoxically remains highly prevalent among pregnant women across various regions, contributing to increased risks of preeclampsia, gestational diabetes mellitus, preterm birth, low birth weight, and long-term developmental complications in offspring. The complex interplay of cultural practices, lifestyle factors, dietary patterns, and physiological variations creates unique challenges in addressing this preventable nutritional deficiency. Limited comprehensive research exists from South Indian populations, particularly from teaching hospitals serving diverse demographic groups, highlighting critical knowledge gaps that must be addressed to develop effective, context-specific interventions and evidence-based public health policies.

Objective: This study aimed to determine the prevalence of vitamin D deficiency among pregnant women attending a tertiary care teaching hospital in North Coastal AP in South India and to comprehensively evaluate associations between vitamin D status and multiple determinants including sociodemographic characteristics (age, education, socioeconomic status, residential location), clinical parameters (gestational age, pre-pregnancy BMI, reproductive history), lifestyle factors (sunlight exposure patterns, clothing practices, dietary habits, physical activity), and compliance with routine supplementation protocols. Additionally, the study sought to identify independent risk factors through multivariate analysis and generate evidence-based recommendations for enhanced screening, prevention, and treatment strategies tailored to regional populations.

Methods: A comprehensive hospital-based cross-sectional study was conducted among 230 carefully selected pregnant women in their third trimester (≥36 weeks gestation) attending the Obstetrics and Gynecology Department at GIMSR Hospital, Visakhapatnam, between October 2022 and March 2024. Participants were recruited through systematic random sampling to ensure representative population coverage. Extensive data collection involved administration of structured, validated questionnaires through trained personnel, capturing detailed information on demographics, lifestyle factors, dietary patterns, supplementation compliance, and clinical parameters. Comprehensive anthropometric measurements were obtained using standardized protocols. Skin pigmentation was assessed using the internationally validated Fitzpatrick Skin Type Classification system. Serum 25-hydroxyvitamin D [25(OH)D] concentrations were measured using high-precision electrochemiluminescence immunoassay (ECLIA) technology with rigorous quality control measures. Vitamin D status was categorized according to Endocrine Society guidelines: deficient (<20 ng/mL), insufficient (20-29 ng/mL), or sufficient (≥30 ng/mL). Statistical analysis employed SPSS version 25.0 with appropriate univariate and multivariate techniques, including chi-square tests for categorical variables, t-tests for continuous variables, and logistic regression for risk factor identification.

Results: The study revealed an alarmingly high prevalence of vitamin D deficiency affecting 76.1% (n=175) of pregnant women, with an additional 21.7% (n=50) demonstrating insufficient levels, leaving only 2.2% (n=5) with adequate vitamin D status. The mean serum 25(OH)D concentration was critically low at 14.23 ± 8.33 ng/mL, with values ranging from 1.1 to 52.0 ng/mL, indicating widespread severe deficiency across the study population. Vitamin D deficiency demonstrated strong statistical associations with limited sunlight exposure patterns (p<0.001, χ²=178.6) and darker skin pigmentation according to Fitzpatrick classification (p<0.001, χ²=41.17). A clear dose-response relationship emerged between weekly sunlight exposure duration and vitamin D status, with women receiving minimal exposure (≤1.5 hours weekly) showing deficiency rates exceeding 95%, while those with optimal exposure (≥3 hours weekly) demonstrated significantly improved status with some achieving sufficiency. Surprisingly, no significant associations were detected with age groups (p=0.27), socioeconomic status classifications (p=0.29), urban versus rural residential location (p=0.32), educational attainment levels (p=0.79), compliance with routine calcium and vitamin D supplementation protocols (p=0.19), gestational age categories (p=0.81), or pre-pregnancy BMI classifications (p=0.98), suggesting that deficiency transcends traditional demographic and socioeconomic boundaries in this population.

Conclusion: This comprehensive investigation demonstrates an extraordinarily high prevalence of vitamin D deficiency among pregnant women in North Coastal AP in South India, representing a critical public health emergency requiring immediate, coordinated intervention strategies. The findings reveal fundamental inadequacies in current prevention and treatment approaches, despite routine supplementation protocols and abundant regional sunlight availability. The predominant associations with modifiable factors (sunlight exposure patterns) and non-modifiable characteristics (skin pigmentation) underscore the urgent need for personalized, evidence-based interventions. Priority actions must include implementation of enhanced supplementation protocols with higher doses tailored to individual risk profiles, development of targeted screening programs for high-risk populations, creation of comprehensive health education initiatives emphasizing optimal sun exposure practices, establishment of dietary counseling programs, and advocacy for food fortification policies adapted to regional dietary patterns. The study's findings have profound implications for maternal and child health policy development, clinical practice guidelines, and public health programming, demanding immediate attention from healthcare providers, policymakers, and public health authorities to address this preventable crisis affecting the vast majority of pregnant women in the region.

Keywords: Vitamin D Deficiency; Pregnancy; Maternal Nutrition; Prevalence; 25-Hydroxyvitamin D; Sunlight Exposure; Skin Pigmentation; North Coastal AP in South India; Supplementation; Prenatal Care; Public Health; Maternal Health; Fetal Development; Nutritional Assessment; Cross-sectional Study; Risk Factors; Health Policy; Prevention Strategies; Clinical Guidelines; Population Health