bims-vitmet Biomed News
on Vitamin metabolism
Issue of 2025–09–21
ten papers selected by
Onurkan Karabulut, Berkeley City College



  1. Am Fam Physician. 2025 Sep;112(3): 294-300
      Vitamin B12 deficiency occurs in approximately 2% to 3% of adults in the United States. Risk factors include malabsorptive processes, limited dietary intake of vitamin B12, use of certain medications (eg, metformin, proton pump inhibitors), and older age. Symptoms vary based on the severity of vitamin B12 deficiency but may include fatigue, brain fog, depression, peripheral neuropathy, and ataxia. Although universal screening is not recommended, testing should be considered in patients with at least one risk factor for and one clinical feature of vitamin B12 deficiency. Initial testing includes total serum vitamin B12 level, which is diagnostic for deficiency if less than 180 pg/mL. Borderline levels (180-350 pg/mL) warrant a methylmalonic acid measurement, which is diagnostic for vitamin B12 deficiency if elevated. Patients without a clear cause of deficiency should undergo further testing for atrophic gastritis with a Helicobacter pylori test and evaluation for autoantibodies associated with autoimmune gastritis. Oral vitamin B12 supplementation can be used in most patients and is noninferior to intramuscular supplementation. Intramuscular administration should be considered in patients with severe deficiency or neurologic manifestations. Vitamin B12 levels that are persistently elevated (greater than 1,000 pg/mL on two measurements) have been associated with solid tumors, hematologic malignancy, and increased risk of cardiovascular death.
  2. HIV Med. 2025 Sep 20.
       OBJECTIVES: Despite effective antiretroviral therapy (ART), chronic liver diseases remain a leading cause of morbidity and mortality among people with HIV, with metabolic dysfunction-associated steatotic liver disease (MASLD) now the predominant etiology. Vitamin D deficiency is also highly prevalent in this population. We synthesize current evidence on the interplay between HIV, liver disease, and vitamin D deficiency, and highlight implications for risk stratification and therapeutic research in this population.
    METHODS: A targeted PubMed search was conducted using terms for HIV, liver disease, fibrosis, and vitamin D, supplemented by reference screening. We prioritized peer-reviewed studies and guidelines addressing liver disease epidemiology and mechanisms in people with HIV, vitamin D biology, and associations between vitamin D status and hepatic injury. Comparative data from non-HIV populations were also reviewed.
    RESULTS: People with HIV face a high burden for chronic liver diseases due to MASLD, viral hepatitis coinfections, and hepatotoxic exposures such as alcohol and ART. Pathogenesis involve persistent immune activation, hepatic stellate cell activation, and systemic inflammation. Vitamin D deficiency is frequent in people with HIV and, in non-HIV populations, correlates with higher prevalence of MASLD and fibrosis. Emerging evidence suggests plausible links through immune modulation, oxidative stress, and fibrogenesis, though causality remains unproven.
    CONCLUSIONS: The intersection of HIV, MASLD, and vitamin D deficiency is biologically plausible and clinically relevant yet underexplored. Longitudinal studies with standardized MASLD phenotyping and vitamin D assessment are warranted. Meanwhile, integrating metabolic risk assessment with vitamin D evaluation may support more holistic liver care in people with HIV, while interventional trials should clarify whether vitamin D optimization improves hepatic and extrahepatic outcomes.
    Keywords:  antiretroviral therapy; immune activation; liver fibrosis; metabolic dysfunction‐associated steatotic liver disease; viral hepatitis
    DOI:  https://doi.org/10.1111/hiv.70117
  3. Am J Hum Biol. 2025 Sep;37(9): e70143
       OBJECTIVES: Folate and vitamin B12 are essential micronutrients involved in one-carbon metabolism. Deficiencies in these nutrients can elevate homocysteine levels, a recognized risk factor for hypertension. This study investigates the prevalence of folate and vitamin B12 deficiencies, hyperhomocysteinemia, and their association with hypertension in a North Indian population.
    METHODS: This cross-sectional study analyzed data from 1398 adult participants aged 30-75 years from rural Punjab, India. Biochemical parameters, including folate, vitamin B12, and homocysteine levels, were assessed using the Chemiluminescence Immunoassay technique. Hypertension was defined as SBP ≥ 140 mmHg and DBP ≥ 90 mmHg or the use of antihypertensive medication.
    RESULTS: The findings revealed a sizable prevalence of folate (26.4%) and vitamin B12 (30.7%) deficiencies, along with a high prevalence of hyperhomocysteinemia (64.8%). Homocysteine levels showed an inverse relationship with folate and vitamin B12 levels, though this association was evident only up to a specific threshold. Further, hyperhomocysteinemia was associated with prehypertension and hypertension, and low folate with prehypertension. Paradoxically, a positive correlation was observed between folate levels and blood pressure.
    CONCLUSIONS: These findings underscore the widespread prevalence of micronutrient deficiencies and hyperhomocysteinemia and their potential association with hypertension. The study also highlights the importance of establishing upper cutoff levels for folate and vitamin B12 to refine dietary and supplementation guidelines. The positive correlation between folate levels and blood pressure suggests potential interference with cellular nutrient uptake in hypertensive individuals, warranting further investigation.
    Keywords:  cardiovascular disease; hyperhomocysteinemia; hypertension; micronutrient
    DOI:  https://doi.org/10.1002/ajhb.70143
  4. J Nutr Metab. 2025 ;2025 3033218
      Background: According to the last national survey in 1998, the prevalence of vitamin A deficiency (VAD) was as high as 61% in the Democratic Republic of the Congo (DRC), leading to the implementation of the vitamin A supplementation (VAS) programme. The available data are outdated and require situation analysis and vitamin A status data. While these data are missing, the relevance of the VAS programme is currently at the centre of debate, and it is important to understand how policymakers and programme planners perceive VAS. This study aims to explore the insights of policymakers and programme planners regarding its relevance and justification. Methods: This study used an exploratory qualitative design. Data were collected using key informant interviews with policymakers and programme planners at the national, provincial and health zone levels, including a total of 25 participants. Data were analysed using thematic analysis. Results: The participants recognised the relevance of VAS in reducing morbidity and mortality, especially in children. However, they identified challenges in communication and delivery mechanisms, such as insufficient supplement supply and a lack of provider motivation. The participants' opinions diverged regarding the justification of the VAS programme. Some participants perceived VAS as an essential strategy due to its benefits, while others advocated for alternative, cost-effective approaches, such as improving vitamin A dietary intake through fortification. Conclusion: Although VAS was considered important, our findings highlight the need to investigate alternative approaches, such as promoting affordable vitamin A-rich foods. There is an urgent need for more objective information regarding vitamin A status in the child population, and further research on VAD is necessary to evaluate the impact of the VAS programme.
    Keywords:  DRC; justification; policymakers; programme planners; qualitative study; relevance; vitamin A supplementation
    DOI:  https://doi.org/10.1155/jnme/3033218
  5. Trop Doct. 2025 Sep 16. 494755251378821
      Vitamin B12 deficiency can manifest in various forms, including skin changes in the form of hyperpigmentation. The hyperpigmentation in vitamin B12 deficiency commonly presents over the hands and feet, but presenting over the face and oral cavity is very rare. Here we describe an interesting case where there was hyperpigmentation in the face and oral cavity which was mimicking Addison's disease, but the actual diagnosis was vitamin B12 deficiency. This case stresses that knowing the uncommon manifestations of common disease is more important than knowing the common manifestations of uncommon disease.
    Keywords:  Asia; community health
    DOI:  https://doi.org/10.1177/00494755251378821
  6. J Alzheimers Dis. 2025 Sep 19. 13872877251379700
      Dementia is a progressive neurodegenerative disorder characterized by cognitive decline that interferes with daily functioning, particularly in the elderly. As one of the leading causes of disability among older adults, dementia remains a significant public health concern. Emerging evidence suggests that certain vitamins may play a crucial role in the prevention and management of cognitive impairment. This review explores the potential impact of key micronutrients specifically water-soluble vitamins such as vitamin C and B-complex (B1, B2, B3, B5, B6, B9, B12), and fat-soluble vitamins A, D, E, and K on dementia pathogenesis and cognitive function. Vitamin B deficiencies have been associated with brain atrophy, an early indicator of cognitive decline, and supplementation has shown promise in enhancing memory and slowing brain shrinkage. Similarly, vitamin C exhibits antioxidative properties that may protect against neurodegeneration. While nutritional support, particularly through micronutrient intake, is increasingly considered a viable strategy for cognitive preservation, findings from epidemiological and clinical studies remain mixed. These inconsistencies highlight the need for further research to determine optimal dosing, efficacy, and long-term impact of vitamin supplementation in dementia prevention. A well-balanced diet rich in essential vitamins may support brain health, but individual variability suggests the importance of personalized nutritional interventions. This review underscores the potential role of vitamins in maintaining cognitive health and calls for continued investigation into their therapeutic utility in delaying or preventing dementia.
    Keywords:  Alzheimer's disease; brain health; dementia; vitamins
    DOI:  https://doi.org/10.1177/13872877251379700
  7. Clin Chim Acta. 2025 Sep 16. pii: S0009-8981(25)00494-2. [Epub ahead of print] 120615
       BACKGROUND: Deficiencies in fat-soluble vitamins (FSVs) have been linked to various systemic disorders. In this study, we introduce a novel and straightforward assay for the analysis of FSVs, suitable for large-scale sample screening while reducing laboratory testing costs.
    METHODS: The method, termed sodium-acetonitrile extraction (SoAce), was developed and validated for the quantification of selected FSVs, including Vitamin A (retinol), Vitamin D2 (25-hydroxyvitamin D2), Vitamin D3 (25-hydroxyvitamin D3), Vitamin E (α-tocopherol), and Vitamin K1 (phylloquinone). A saturated sodium chloride solution combined with acetonitrile was employed as the extraction reagent. Mass spectrometric detection was carried out using a triple quadrupole mass spectrometer in positive ion mode via an APCI source. Method validation was conducted in accordance with Chinese regulatory guidelines and the C62-A standard.
    RESULTS: Using the SoAce-liquid chromatography-tandem mass spectrometry (LC-MS/MS) approach, FSVs were successfully separated and quantified within 30 min. The assay demonstrated excellent linearity, with all regression coefficients exceeding 0.996. The lower limit of quantification (LLOQ) was determined as 12.5 ng/mL for Vitamin A, 0.31 ng/mL for Vitamin D2, 1.56 ng/mL for Vitamin D3, 625 ng/mL for Vitamin E, and 0.08 ng/mL for Vitamin K1. Specificity, stability, accuracy, and precision were all evaluated and met the required validation criteria. A comparative analysis against an existing commercial FSV kit using the same instrumentation revealed strong correlation, with coefficients ranging from 0.928 to 0.962.
    CONCLUSIONS: The developed SoAce-LC-MS/MS method fulfills the requirements for rapid and reliable assessment of FSV status in human serum. Further studies are warranted to fully explore the potential applications and clinical utility of this assay.
    Keywords:  Fat-soluble vitamins; LC-MS/MS; Pretreatment; Sodium-acetonitrile method
    DOI:  https://doi.org/10.1016/j.cca.2025.120615
  8. Cureus. 2025 Aug;17(8): e90042
      Vitamin D (VD) is a key mineral providing critical modulation of reduction-oxidation homeostasis within biological systems. VD and the VD receptor coordinate essential cellular activities, including mitochondrial electron transport, respiration, antioxidation, gene regulation, and calcium transportation. Reactive oxygen species (ROS), a natural by-product of cellular metabolism, play a prominent role in the mechanisms of biological antioxidant systems and form the basis of antioxidant therapies. However, ROS may also perpetuate pathological processes when produced in excess secondary to inflammatory pathways. Aging processes within cells rely on this reduction-oxidation homeostasis. Thus, the interaction with VD, its receptor, mitochondria, and oxidative stress forms the basis of nearly every known degenerative pathology, citing examples summarized throughout this review. Recent literature has highlighted the increasingly prominent role of VD deficiency as a unifying factor within the ubiquitous degenerative changes that ultimately progress these conditions discussed, such as metabolic syndrome, brain disease, cardiovascular disease, GI disease, immune dysfunction, musculoskeletal disease, and other age-related disorders. Lastly, the paradox of bacterial survival under lethal oxidative stress conditions is presented to explore the proposed mechanisms of such activity and the consideration of antioxidant therapies in the future.
    Keywords:  antioxidant; deficiency; oxidative stress; pathology; vitamin d
    DOI:  https://doi.org/10.7759/cureus.90042
  9. Curr Med Chem. 2025 Sep 11.
      The strong antioxidant vitamin C has been researched for its potential use in the prevention and treatment of cancer. Scavenging free radicals and lowering oxidative stress, which is essential in carcinogenesis, helps to protect cells. Excessive levels of vitamin C can produce hydrogen peroxide and selectively kill cancer cells in the tumor microenvironment by exerting pro-oxidant effects. Normal cells might be spared, indicating a possible window for treatment. Additionally, vitamin C affects important cellular functions that contribute to the development of tumors, including angiogenesis, inflammation, immune response modulation, and epigenetic regulation. Sensitizing tumor cells or shielding healthy tissue from harm caused by treatment may increase the effectiveness of traditional cancer treatments. Recent clinical investigations have revisited the use of high-dose intravenous vitamin C in both monotherapy and combination regimens. While some trials report improvements in quality of life, reduced chemotherapy side effects, and extended survival in specific cancer types, robust evidence of a consistent anticancer effect remains lacking due to variability in study design, cancer type, dosing protocols, and patient populations. Nonetheless, these studies have renewed interest in understanding the pharmacodynamics and clinical utility of vitamin C in oncology. Vitamin C should be considered an investigational approach rather than a standard component of cancer therapy. This review provides a comprehensive overview of the biochemical properties of Vitamin C, its anticancer mechanisms, experimental evidence, clinical data, controversies, and future directions.
    Keywords:  Vitamin C; antioxidant; cancer; chemotherapeutic agents; cytotoxicity.; reactive oxygen species
    DOI:  https://doi.org/10.2174/0109298673411854250808061949