Vitamin D Deficiency and Correlation to Blood Markers in Pregnancy

Written by Jessica Patella, ND. The study concluded that pregnant women with inadequate plasma vitamin D levels, showed lower MCV, MCH, folate levels and vitamin B12 levels compared to those with adequate levels of vitamin D. 

An estimated 17.8% of women globally are deficient (<30 ng/mL) in vitamin D1,2.  This is especially concerning during reproductive years, since the infant relies solely on the maternal blood plasma for vitamin D1,3.  Recent research aimed to study the correlation between maternal plasma vitamin D levels (25-OHD) and maternal blood parameters and fetal anthropometric outcomes1.  Researchers found vitamin D deficiency was correlated with changes in blood markers, especially folate and vitamin B121.

Vitamin D is an essential fat-soluble vitamin that is found in foods but is primarily made by the body through exposure to sunlight1,4.  A lack of exposure to sunlight or use of sun protection can lead to low vitamin D levels1,5.  Vitamin D has been shown in animal studies to regulate inflammation in the placenta thereby reducing the risk of pre-eclampsia1,6.  Vitamin D has also been shown to play a role in fetal brain development and lung maturation1,7.  Deficiency is also associated with reduced hematopoiesis, the formation of new blood cells, which is important in the pregnant women due to increased blood volume during pregnancy1,8.

The research included 103 pregnant women that completed a food frequency questionnaire, which included questions regarding sun exposure.  Patients were then stratified based on their vitamin D plasma levels as either adequate (> or equal to 20 ng/mL; n=59) or inadequate (<20 ng/mL; n=44).  The results were as follows:

  • Pregnant women with inadequate vitamin D levels had higher red blood cell (RBC) counts than those with adequate plasma vitamin D levels (4.3 +/- 0.5 vs 4.1 +/- 0.4 106/uL; p=0.012).
  • The mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) levels were higher in the group with adequate plasma vitamin D than those without (MCV: 90.4 +/- 6.7 vs 86.4 +/- 8.5 fL; p=0.003 and MCH: 29.6 +/- 2.7 vs 28.1 +/- 3.3 pg; p=0.008).
  • Plasma folate and vitamin B12 levels were significantly higher in the group with adequate vitamin D levels than those without (folate: 15.6 +/- 5.9 vs 12.6 +/- 5.9 ng/mL; p=0.006 and B12: 352 +/- 147 vs 289 +/- 174 pg/mL; p=0.001).
  • The frequency of fish consumption was the only food that showed significant difference between plasma vitamin D levels (p=0.008).
  • There was no significant difference between the groups in the baby’s birth height, weight or head circumference at delivery.

In conclusion, pregnant women with inadequate plasma vitamin D levels, showed lower MCV, MCH, folate levels and vitamin B12 levels compared to those with adequate levels of vitamin D.  A limitation of the study was the small sample size.  Future research should consider optimal vitamin D intake in pregnant women to maintain adequate vitamin D levels1.

Source: Hou, Yi Cheng, Jing Hui Wu, Lu Lu Zhao, Yin Guang Zhang, and Chyi Huey Bai. “The Correlation Between Plasma Vitamin D and Blood Parameters in Prenatal Women.” Nutrients 17, no. 16 (2025): 2710.

© 2025 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/ licenses/by/4.0/).

Click here to read the full text study.

Posted October 17, 2025.

Jessica Patella, ND, is a naturopathic physician specializing in nutrition and homeopathic medicine and offers a holistic approach to health.  She earned her ND from Sonoran University (formerly Southwest College of Naturopathic Medicine in Tempe, AZ).  Dr. Patella has been involved in research since high school, when she presented her research at University of Florida on Group B Strep in pregnant women. While earning a bachelors in exercise physiology at Florida State University, her honors research was examining lifestyle effects on glucose levels in women. Dr. Patella was also a research assistant while in naturopathic medical school and has been writing for the Natural Health Research Institute since she graduated from Sonoran University in 2009. Dr. Patella currently teaches a variety of classes all related to human health.

References:

  1. Hou YC, Wu JH, Zhao LL, Zhang YG, Bai CH. The Correlation Between Plasma Vitamin D and Blood Parameters in Prenatal Women. Nutrients. Aug 21 2025;17(16)doi:10.3390/nu17162710
  2. Cui A, Zhang T, Xiao P, Fan Z, Wang H, Zhuang Y. Global and regional prevalence of vitamin D deficiency in population-based studies from 2000 to 2022: A pooled analysis of 7.9 million participants. Front Nutr. 2023;10:1070808. doi:10.3389/fnut.2023.1070808
  3. De-Regil LM, Palacios C, Lombardo LK, Peña-Rosas JP. Vitamin D supplementation for women during pregnancy. Cochrane Database Syst Rev. Jan 14 2016;(1):Cd008873. doi:10.1002/14651858.CD008873.pub3
  4. Tobias DK, Luttmann-Gibson H, Mora S, et al. Association of Body Weight With Response to Vitamin D Supplementation and Metabolism. JAMA Netw Open. Jan 3 2023;6(1):e2250681. doi:10.1001/jamanetworkopen.2022.50681
  5. Health Promotion Administration TMoHaW. Nutrition and Health Survey in Taiwan (8th Version) Nutrition and Health Survey in Taiwan (NAHSIT). 2020.
  6. Liu NQ, Larner DP, Yao Q, et al. Vitamin D-deficiency and sex-specific dysregulation of placental inflammation. J Steroid Biochem Mol Biol. Mar 2018;177:223–230. doi:10.1016/j.jsbmb.2017.06.012
  7. Wagner CL, Hollis BW. The Implications of Vitamin D Status During Pregnancy on Mother and her Developing Child. Front Endocrinol (Lausanne). 2018;9:500. doi:10.3389/fendo.2018.00500
  8. Olmuşçelik O, Sevindik Ö G. Correlation between serum vitamin D level and dichotomous distribution of hematological parameters in a cohort of 12709 patients. Turk J Med Sci. Dec 17 2020;50(8):1941–1950. doi:10.3906/sag-2008-124

 

Comments (0)

Leave a Reply

Back To Top