Analysis of Vitamin D and Vitamin B12 Status during the First Trimester of Pregnancy in a Tertiary Care Centre

Abstract

Vitamin D and vitamin B12 are essential micronutrients with distinct but complementary roles in maternal and fetal health. Vitamin D regulates calcium and phosphate homeostasis, supports fetal skeletal development, and modulates immune function; deficiency during pregnancy has been linked to complications including pre-eclampsia, gestational diabetes, preterm birth and impaired fetal bone mineralization. [1,2] Despite abundant sunlight in many regions of India, multiple studies and reviews have documented a high prevalence of vitamin D insufficiency and deficiency among pregnant women, driven by limited sun exposure, skin pigmentation, cultural clothing practices, urban lifestyles and low dietary intake of vitamin D-rich foods. [3,4,5] Vitamin B12 is a key cofactor in one-carbon metabolism required for DNA synthesis, methylation reactions and neural development. Maternal B12 deficiency is associated with neural tube defects, intrauterine growth restriction and adverse neuro-developmental outcomes in offspring. [6,7] India shows a high burden of maternal B12 deficiency in many cohorts, particularly among vegetarians and low-income populations lacking regular animal-source foods. [8,9] Global and national guidance acknowledges the importance of assessing maternal micronutrient status. The World Health Organization's antenatal care guidance reviews vitamin D supplementation and notes potential benefits for maternal serum status and some pregnancy outcomes while not recommending universal supplementation for all pregnant women without risk stratification.[10] Indian antenatal protocol sand dietary guidelines (ICMR/NIN) emphasize micronutrient support during pregnancy, including calcium with vitamin D in antenatal management where indicated. [11] Given the regional variability and population-specific risk factors, point-prevalence studies of vitamin D and B12 during early pregnancy are valuable to inform screening and supplementation strategies. This study aims to examine the prevalence of vitamin D and vitamin B 12 status during the first trimester among pregnant women attending a tertiary care center in North India, and to explore associations between these two micronutrients and demographic factors.