Unveiling The Metabolic-Neurophysiological Interplay of Vitamin B₁₂ In Young Adults: A Systematic Review
DOI:
https://doi.org/10.63682/jns.v14i8.7139Keywords:
vitamin B12, Cobalamin, B12 insufficiency, hematological parameters, neurological function, cognitive function, homocysteineAbstract
Vitamin B12 (cobalamin) is a vital micronutrient involved in DNA synthesis, red blood cell formation, and neurological function. Its deficiency, increasingly common among young adult females—particularly those adhering to vegetarian or vegan diets—can result in biochemical imbalances, disrupted nerve function, and cognitive impairments. This review consolidates current findings on the physiological implications of Vitamin B12 deficiency in this demographic. We explore biochemical markers such as homocysteine and methylmalonic acid, the impact on nerve conduction and electrophysiology, and associated neurocognitive deficits. We also assess diagnostic strategies and intervention approaches. With the prevalence of plant-based diets rising, this work underscores the need for targeted screening and early correction strategies to mitigate long-term neurological and systemic consequences.
Downloads
Metrics
References
Ahmad, A., et al. (2021). Prevalence of anemia and its correlation with vitamin B12 levels in menstruating women. Journal of Women's Health, 30(6), 752–760.
Allen, L. H. (2009). Causes of vitamin B12 and folate deficiency. Food and Nutrition Bulletin, 29(2_suppl1), S20–S34.
Allen, L. H. (2010). Bioavailability of vitamin B12. Eur. J. Clin. Nutr., 64(10), 1139–1140.
Allen, L. H., de Benoist, B., Dary, O., & Hurrell, R. (2010). Guidelines on food fortification with micronutrients. World Health Organization.
Baltacı, D., et al. (2013). Association of vitamin B12 with obesity, overweight, insulin resistance and metabolic syndrome, and body fat composition: A primary care-based study. Medicinski Glasnik, 10(2), 203–207.
Bhatia, P., et al. (2012). Subclinical vitamin B12 deficiency in Indian vegetarians: A cause for concern. Indian Journal of Clinical Biochemistry, 27(3), 279–283.
Bryan, J., Calvaresi, E., & Hughes, D. (2002). Short-term folate, vitamin B-12 and vitamin B-6 supplementation and cognitive performance in healthy older men. Nutrition Research, 22(3), 297–298.
Chakraborty, S., et al. (2018). Prevalence of vitamin B12 deficiency in healthy Indian school‐going adolescents from rural and urban localities and its relationship with various anthropometric indices: A cross‐sectional study. Journal of Human Nutrition and Dietetics, 31(1), 106–114.
Clarke, R., et al. (2007). Homocysteine and risk of ischemic heart disease and stroke: A meta-analysis. JAMA, 288(16), 2015–2022.
de Jager, C. A., et al. (2009). Cognitive and clinical outcomes of homocysteine-lowering B-vitamin treatment in mild cognitive impairment: A randomized controlled trial. Int. J. Geriatr. Psychiatry, 24(5), 562–570.
Fedosov, S. N., Brito, A., Miller, J. W., Green, R., & Allen, L. H. (2015). Combined indicator of vitamin B12 status: Modification for missing biomarkers and folate status. Clin. Chem. Lab. Med., 53(8), 1215–1225.
Garcia, M. M., et al. (2018). Vitamin B12 deficiency and depression in young adults: Data from NHANES. J. Affect. Disord., 239, 139–145.
Green, R., & Kinsella, L. J. (1995). Diagnosis of cobalamin deficiency. Neurology, 45(8), 1435–1440.
Hazra, A., et al. (2008). Common variants of FUT2 are associated with plasma vitamin B12 levels. Nat. Genet., 40(10), 1160–1162.
Hazra, A., et al. (2008). Vitamin B12 metabolism in health. Am. Fam. Physician, 77(11), 1473–1480.
Healton, E. B., et al. (1991). Neurologic aspects of cobalamin deficiency. Medicine, 70(4), 229–245.
Hoffbrand, A. V., & Provan, D. (2019). ABC of clinical haematology. BMJ Books.
Hvas, A. M., & Nexo, E. (2006). Holotranscobalamin as early marker of vitamin B12 deficiency. J. Intern. Med., 260(4), 289–298.
Kumar, N., et al. (2015). Vitamin B12 deficiency: An important reversible co-morbidity in neuropsychiatric manifestations. J. Clin. Neurosci., 22(1), 10–15.
Kuzminski, A. M., et al. (1998). Effective treatment of cobalamin deficiency with oral cobalamin. Blood, 92(4), 1191–1198.
Langan, R. C., & Zawistoski, K. J. (2011). Update on vitamin B12 deficiency. Am. Fam. Physician, 83(12), 1425–1430.
Langan, R. C., & Zawistoski, K. J. (2011). Update on vitamin B12 deficiency. Am. Fam. Physician, 83(12), 1425–1430.
Lindenbaum, J., et al. (1988). Neuropsychiatric disorders from B12 deficiency without anemia. N. Engl. J. Med., 318(26), 1720–1728.
Mathur, R., et al. (2001). Effect of vitamin B12 deficiency on reproductive performance in female rats. Nutr. Res., 21(4), 537–544.
Mattson, M. P., & Shea, T. B. (2003). Folate and homocysteine metabolism in neurodegenerative disorders. Trends Neurosci., 26(3), 137–146.
Miller, A. L., et al. (2002). Vitamin B12 and cognition in the elderly: A controlled trial. J. Am. Geriatr. Soc., 50(1), 20–26.
Miller, J. W., et al. (2002). Homocysteine, B12, and memory function. Am. J. Clin. Nutr., 75(3), 494–501.
Nexo, E., et al. (2002). Holotranscobalamin as marker of vitamin B12 homeostasis. Am. J. Clin. Nutr., 75(2), 291–295.
O’Leary, F., & Samman, S. (2010). Vitamin B12 in health and disease. Nutrients, 2(3), 299–316.
Okuda, K., et al. (1994). Methylcobalamin vs. cyanocobalamin in diabetic neuropathy. Clin. Ther., 16(5), 819–830.
O'Leary, F., & Samman, S. (2010). Vitamin B12 in health and disease. Nutrients, 2(3), 299–316.
Refsum, H., et al. (2006). Facts and recommendations on total homocysteine determinations. Clin. Chem., 50(1), 3–32.
Reynolds, E. (2006). Vitamin B12, folate, and the nervous system. Lancet Neurol., 5(11), 949–960.
Scalabrino, G. (2001). Cobalamin in subacute combined degeneration and beyond. Exp. Neurol., 168(2), 302–306.
Sinha, R., et al. (2022). Vitamin B12 deficiency impairs reproductive performance in female rats. Reprod. Toxicol., 105, 1–9.
Stabler, S. P. (2013). Clinical practice: Vitamin B12 deficiency. N. Engl. J. Med., 368(2), 149–160.
Suri, H., Senghor, K. A., Vinodhini, V., Sai, K. T., Charles, J., & Rooban, S. (2024). Comparison of single-point insulin sensitivity estimator (SPISE) index and cognitive performance in vitamin B12-deficient young adults: An analytical cross-sectional study. Journal of Family Medicine and Primary Care.
Tiemeier, H., et al. (2002). Vitamin B12, folate, and homocysteine in depression. Am. J. Psychiatry, 159(12), 2099–2101.
van Gool, W. A., et al. (2003). Homocysteine and dementia: A review. J. Intern. Med., 254(5), 419–429.
Downloads
Published
How to Cite
Issue
Section
License
This work is licensed under a Creative Commons Attribution 4.0 International License.
You are free to:
- Share — copy and redistribute the material in any medium or format
- Adapt — remix, transform, and build upon the material for any purpose, even commercially.
Terms:
- Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
- No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.
