B12 Levels Research Articles

Effects of Vitamin B 12 Supplementation on Cognitive Function in Survivors of Hemorrhagic Stroke

Background: Hemorrhagic stroke often leads to significant cognitive deficits in survivors. Vitamin B12 plays a crucial role in neurological functions, suggesting its potential in cognitive recovery post-stroke. This retrospective cohort study explored the impact of Vitamin B12 supplementation on cognitive function in hemorrhagic stroke survivors, a subject that holds substantial importance in stroke rehabilitation and patient care. Objective: The primary objective was to evaluate the effectiveness of Vitamin B12 supplementation in improving cognitive function, as measured by MMSE and MoCA scores, in adults who have recently survived a hemorrhagic stroke. Methods: The study included 75 adults diagnosed with hemorrhagic stroke within the last six months. Participants were administered a daily oral dose of 1000 mcg of Vitamin B12 for three months. Cognitive function was assessed using the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) at the start and end of the supplementation period. Additionally, Vitamin B12 levels were measured at baseline and after three months to gauge the physiological uptake of the supplement. Results: The study observed significant improvements in cognitive function, with the MMSE score increasing by an average of 2.2 (p=0.0463) and the MoCA score by 5.8 (p=0.0410). There was also a notable average increase of 400 pg/mL in Vitamin B12 levels (p<0.05). The supplementation was generally well-tolerated, with only 8% of participants reporting minor adverse effects, a rate not statistically significant (p>0.05). Conclusion: The study provides preliminary evidence that Vitamin B12 supplementation may positively impact cognitive function in survivors of hemorrhagic stroke. However, due to the study's limitations, further extensive research is necessary to corroborate these findings and to deepen our understanding of the role of Vitamin B12 in post-stroke cognitive recovery.

Micronutrient Status in Pregnant Women after Metabolic Bariatric Surgery in the United Arab Emirates: A Prospective Study.

Metabolic bariatric surgery (MBS) helps reduce comorbidities, such as hypertension and gestational diabetes, and is more effective than diet management for women with obesity-related health issues. Vitamin B12, vitamin D, and iron play important roles in ensuring the health of a neonate. However, pregnancies occurring after MBS may face complications related to micronutrient deficiencies, particularly of vitamins B12 and D and iron. This study aimed to investigate the vitamin B12, vitamin D, ferritin, and iron status of pregnant women who underwent MBS compared with women without MBS history. The study included 217 pregnant women (105 with a history of MBS and 112 without a history of MBS) who visited a major maternity hospital in Abu Dhabi, United Arab Emirates (UAE) between July 2021 and November 2022. The maternal vitamin B12, vitamin D, iron, and ferritin levels were measured twice, initially during the first or second trimester and subsequently during the third trimester. The iron was measured once during the pregnancy. Vitamin B12 deficiency was higher among pregnant women with MBS history compared to non-bariatric pregnant women (24.4% vs. 3.9%, p < 0.001). Women with a history of MBS had a higher prevalence of vitamin D deficiency (62.3% vs. 37.7%, p < 0.002). Linear regression analysis indicated that vitamin B12 levels decreased by 55 pg/mL in women with a history of MBS and by 4.6 pg/mL with a unit increase in body mass index (kg/m2). Furthermore, vitamin D levels in women with a history of MBS decreased by 4.9 ng/mL during pregnancy. Metabolic bariatric surgery is associated with vitamin B12, vitamin D, and iron deficiencies during pregnancy.

Evaluation of Neurodevelopmental Screening Test Scores in Children with Vitamin B12 Deficiency.

Vitamin B12 deficiency can lead to hematological findings, neurological symptoms, and neurodevelopmental delay. The aim of this study was to investigate the impact of vitamin B12 deficiency on the neurodevelopment of children. This study included 89 children aged between 6 and 24 months without any complaints; 44 of these were evaluated in the study group (serum vitamin B12 <300 pg/mL) and 45 in the control group (serum vitamin B12 ≥300 pg/mL). Denver Developmental Screening Test II (DDST-II) and the Social Communication Area Screening Test (SCAST) were evaluated in each participant. The mean vitamin B12 level in the study group was 206.11 ± 9.1 pg/mL, and in the control group, it was 540.65 ± 24.1 pg/mL. When DDST-II results were analyzed, the rate of getting suspicious and abnormal results in the study group was significantly higher compared with the control group (p = 0.001). The rate of the "risky" SCAST results of the cases was found to be statistically significantly higher in the study group than in the control group (p = 0.003). Vitamin B12 values of patients with suspicious or abnormal DDST-II results and with risky SCAST results were found to be statistically significantly lower than those with normal neurodevelopmental screening tests results (p = 0.001 and p = 0.001, respectively). Vitamin B12 deficiency can lead to neurodevelopmental delay in children, even in the absence of neurological and hematological symptoms or complaints, which highlights the importance of early detection and intervention of vitamin B12 deficiency.

The effect of Folic Acid, B12, D, and E Vitamins and Melatonin levels in the follicular fluid taken by the Intracytoplasmic Sperm Injection method on pregnancy.

It has been demonstrated that the composition of the follicular fluid and many internal/external factors affect success in subfertile couples undergoing intracytoplasmic sperm injection (ICSI). We examined the effect of folic acid, B12, D, and E vitamins and melatonin values in follicular fluid on pregnancy in women with low, normal, and high ovarian reserves who underwent ICSI. Our study was conducted at Samsun Medical Park Hospital between January 2021 and February 2022. Follicular fluid induction samples were taken from 96 infertile women with low, normal, and high ovarian reserve, and ICSI was applied. Folic acid, B12, D, and E vitamins and melatonin levels were measured in follicular fluid samples by ELISA method. Statistical analyzes were done with SPSS, and ROC curve analyses were used. Nine people with poor reserve, 19 people with normal reserve and 14 people with high reserve became pregnant. Folic acid, Vitamin-D, B12, E and melatonin levels were lower in those with poor ovarian reserve than in those with normal and high ovarian reserve (p<0.05). According to the pregnancy test, the probability of pregnancy was 43,783 times higher with high levels of folic acid, while it was 8,096 times higher for vitamin D. While vitamin B12 levels were 31,474 times more likely to be pregnancies, vitamin E levels were 35,227 times higher. For melatonin, the values showed that the probability of pregnancy increased by 11,564 times. High antioxidants may increase the likelihood of conception in infertile women undergoing ICSI. Therefore, couples who will be treated should be advised to increase these markers, especially melatonin in the follicular fluid.

Long-term late effects in older gastric cancer survivors: Survival analysis using Cox hazard regression model by retrospective electronic health records

PurposeBecause the population of older gastric cancer survivors (GCSs) is growing, understanding the long-term late effects experienced by these GCSs and their impact on survival outcomes is crucial for optimizing survivorship care. This study aims to identify and characterize these effects and investigate their association with survival outcomes.MethodsA retrospective analysis of electronic health records was conducted on 9,539 GCSs diagnosed between 2011 and 2017. The GCSs were divided into two age groups (< 65 and ≥ 65 years) and the long-term late effects were categorized by age using Cox proportional hazard models. The impact of clinical factors and age-specific late effects on survival was evaluated in the older GCSs.ResultsAmong the total GCSs, 37.6% were over and 62.4% were under 65 years of age. Significant differences between the age groups were observed in the cumulative hazard ratios (HRs) for iron and vitamin B12 levels and prognostic nutritional index (PNI) scores. In older GCSs, abnormal iron levels (HR 1.98, 95% CI 1.16–3.41, p = .013) and poor PNI scores (HR 1.59, 95% CI 1.03–2.47, p = .038) were associated with poorer survival outcomes. Additionally, being female was identified as a risk factor for lower survival rates (if male, HR 0.42, 95% CI 0.18–0.98, p = .045).ConclusionThis study highlights the typical long-term late effects experienced by older GCSs. By tailoring survivorship care to address nutritional-, age-, and gender-related factors, the overall survival and quality of life of older GCSs can be improved.

Unveiling the Spectrum of Megaloblastic Anemia: Insights from a Multifaceted Study at Abbas Institute of Medical Sciences, Muzaffarabad

Background: This study aimed to determine the frequency of Megaloblastic Anemia cases presenting in the outpatient department (OPD) and wards of AIMS Hospital in Muzaffarabad, AJ&amp;K. Methods: Conducted at the Pathology department of Abbas Institute of Medical Sciences from May 2022 to October 2022, this case-control study analyzed 125 cases from OPD and wards. Patient interviews, venous blood sample collection, and complete blood picture (CP) analysis, including peripheral film (PF) tests and Vitamin B12 and folates levels reports, were conducted using a Hematology analyzer. Statistical analysis using SPSS version 25.0 was employed. Results: Statistical analysis revealed a mean age of 3.656, with females having a higher frequency of Megaloblastic Anemia, especially during childbearing age. Males had a higher frequency in children and the elderly. The residential distribution showed a balance of village and city dwellers, whereas the patient category breakdown showed a higher frequency in the young age group. Conclusion: The study highlighted Megaloblastic Anemia's serious public health significance, its causes, and the observed trends in the study population. Surgical interventions, particularly abdominal surgeries, were identified as potential contributors. Analyses of peripheral smears revealed varying degrees of anemia severity, with most cases being moderate. The study concluded that Megaloblastic Anemia is more common in females, especially during childbearing age, and in males, especially in children and the elderly. These findings highlight the importance of targeted interventions and nutritional education programs in addressing the specific demographic trends observed in this study population.

Association between vitamin B12 levels and cognitive impairment in older adults

Association between vitamin B12 levels and cognitive impairment in older adults

Low vitamin B12 blood levels in sickle cell disease: Data from a large cohort study in Tanzania.

Sickle cell disease (SCD) is associated with high rates of undernutrition and stunting. Undernutrition in combination with chronic haemolysis may lead to deficiencies in micronutrients necessary for erythropoiesis. Here we examined selected levels of ferritin, vitamins B2 , B6 , B9 and B12 , and vitamin C that were measured in blood samples from 820 SCD patients from Tanzania with no history of hospital admission, infections or painful episodes in the previous 30 days. We studied children (0-8 years), early adolescents (9-14 years), late adolescents (15-17 years) and adults (≥18 years). Severely low levels of vitamin B12 were observed across the four age groups. Despite the lowered vitamin B12 concentrations, total homocysteine concentrations were normal across both genders in all age groups. We found no significant gender-related differences between the other measured micronutrients. In this large SCD population, spanning the whole life cycle, a low level of vitamin B12 was consistently found across both genders and all age groups. Given the pivotal role of vitamin B12 in cellular metabolism, particularly in erythropoiesis, more studies are required to unravel how to better detect clinically relevant vitamin B12 deficiency among SCD patients, and thus to identify more precisely those who need supplementation of vitamin B12 .

Relationship between hysterectomy and global DNA methylation levels in peripheral blood: an exploratory follow-up study

ObjectiveThe present study aims to understand the relationship between hysterectomy and peripheral blood leukocyte (PBL) global DNA methylation independently and in light of selected biochemicals (vitamin B12, folate, homocysteine). Material and methodsFor the present population-based follow-up study, a total of 616 women aged 30–70 years were recruited from Haryana, India. Recruited participants underwent a baseline assessment, which included the determination of menopausal and hysterectomy status and estimation of vitamin B12, folate, homocysteine, and PBL global DNA methylation (5mC) levels. The 5mC levels were analyzed using ELISA-based colorimetric technique. Participants with no history of hysterectomy were followed up after 8 years, and their current menopausal and hysterectomy statuses were determined. ResultThe median PBL 5mC level of the group with hysterectomy was found to be significantly lower than that of those without hysterectomy in the baseline assessment (PBL 5mC = 0.47 vs. 0.74, respectively; p-value = 0.016). However, there was no significant difference in baseline median PBL 5mC levels between women who eventually underwent hysterectomy and those who did not. When stratified for biochemical levels, the trend of PBL global DNA hypomethylation in the hysterectomy group, compared to the no-hysterectomy group, was statistically significant only within the normal folate group. ConclusionThis study suggests a potential association between hysterectomy (or related factors) and global DNA hypomethylation. Further research is warranted to validate the findings of the present study and to advance the existing knowledge regarding the epigenetic implications of hysterectomy.

Incidental detection of raised serum levels of vitamin B12 and its association with neoplasms

Background and objectivesElevated serum levels of vitamin B12 have been associated with oncohematological diseases. However, the relevance of its incidental detection in subjects without a previous diagnosis of cancer is unknown. The aim of this study was to evaluate the relationship between incidental hypercobalaminemia (vitamin B12 > 1000 pg/mL) and the diagnosis of a tumor process in patients without a diagnosis and to establish the risk factors. Material and methodsRetrospective observational study of a cohort of patients with hypercobalaminemia. The incidence of neoplasms was compared with a cohort of patients with vitamin B12 levels <1000 pg/mL. ResultsVitamin B12 determinations of 4800 subjects were selected. Of them, 345 (7.1%) had levels >1000 pg/mL. 68 (28.4%) were excluded due to exogenous administration, 12 (5%) due to insufficient data and 15 (3%) due to having an active neoplasia, selecting 250 patients, with a median follow-up of 22 (IQR 12–39) months. Structural liver disease was detected in 59 (23.6%). 18.2% (44 patients) had solid organ cancer and 17 (7.1%) had malignant hemopathy. The average time from the detection of hypercobalaminemia to the diagnosis of cancer was about 10 months. The median until the diagnosis of neoplasia was higher in the high vitamin B12 group (13 vs. 51 months p < 0.001). Hypercobalaminemia (HR 11.8; 95% CI 2.8–49.6; p = 0.001) and smoking (HR 4.0; 95% CI, 2.15–7.59; p < 0.001) were independent predictors of neoplasia in the multivariate analysis. ConclusionsIncidental detection of serum vitamin B12 levels >1000 pg/mL is high in the population. The diagnosis of solid organ and hematological neoplasia is frequent during the following year of follow-up, with hypercobalaminemia and smoking being predictors of a higher risk of cancer.

Vitamin B12 deficiency in sickle cell patients at the Bamako sickle cell research and control center: About two cases

Vitamin B12 deficiency, also known as hypocobalamemia refers to low blood levels of vitamin B12. The authors report two cases of vitamin B12 deficiency in two sickle cell patients followed at the Bamako sickle cell research center. The objective of this work is to describe this pathology in sickle cell patients and to provide a treatment plan. Keywords: sickle cell anemia, vitamin B12 deficiency, center for reseach and fight against sickle cell disease

Two cases of vitamin B12 deficiency in patients with beta-thalassemia trait: lessons in diagnosis

BackgroundCoexisting pathologies is not a new phenomenon and can cause diagnostic difficulties when they overshadow one another. They may alter the cytomorphology of cells and the machine readings to an extent that the actual diagnosis is missed. One such scenario is created by coexisting megaloblastic anemia and beta-thalassemia trait where the RBC indices and the hemoglobin chromatogram findings conform to neither of the two. Case presentationWe present two cases of anemia presenting with normocytic normochromic indices, increased red cell distribution width (RDW), elevated HbA2 levels and moderately high HbF levels in both of them and an additional low HbA1c in case 2. Upon evaluation of peripheral smear and biochemical tests, a non-immune hemolytic component was also identified with deficient Vit B12 levels in case 1 and highly elevated levels post-supplementation in case 2. ConclusionsTaking together the peripheral smear, erythrogram, chromatogram and biochemical findings, it was deduced that the alterations were caused by coexisting beta-thalassemia trait and megaloblastic anemia. Vit B12 deficiency was the cause behind hemolysis owing to intramedullary destruction of abnormal precursors. Upon supplementation in case 2, the immediate reticulocyte response was the reason behind spuriously low HbA1c.

Association of mild cognitive impairment, dementia and vitamin B12 levels in older adults

AbstractBackgroundVitamin B12 deficiency has been associated with the development of multiple pathologies. However, it is still controversial if the deficiency is associated with cognitive impairment. Objective: To determine the association between cognitive performance and the vitamin B12 levels.MethodCross‐sectional study including 241 adults aged 60 or older, treated as an outpatient at a tertiary care hospital, who had serum levels of vitamin B12. Participans underwent a cognitive assessment and assigned to one of three groups: normal cognition (NC), mild cognitive impairment (MCI), and dementia. Vitamin B12 levels were classified in three categories: sufficiency (&gt;400 pg/ml), subclinical deficiency (201‐400 pg/ml), and absolute deficiency (≤200 pg/ml). Univariate and multivariate linear regression analyzes were used to assess the association between cognitive performance and vitamin B12 levelsResultMean age was 81.4 ± 8.0 years and 68% were women. The prevalence of absolute and subclinical B12 deficiency was 17.8% and 39.8%, respectively. Eigthy participants (33%) had MCI and 70 (29%) dementia. Those with MCI and dementia had lower vitamin B12 levels compaired with NC after adjusting for age, sex and education level (p = 0.019).ConclusionThis study suggests a statistically significant association between global cognitive performance and serum levels of vitamin B12 in older adults

Prevalence of mild cognitive impairment in an urban, community dwelling, elderly population and its association with Serum Vitamin B12 levels in South India.

AbstractBackgroundPrevalence of cognitive disorders is becoming higher in low and middle income societies with increasing lifespan1. Multiple factors contribute to emergence of cognitive disorders including genes, lifestyle, diet and nutrition, co‐morbid metabolic and vascular risk factors 2. There has been only a few studies from India, looking at the prevalence of cognitive impairment in the community. Ageing and dietary preferences pose a higher risk for B12 and Folic acid deficiencies, contributing to cognitive difficulties3. Our study aims to look at the prevalence of cognitive impairment in a community dwelling elderly population and the association of mild cognitive Impairment (MCI) with serum B12 levels.MethodA total of 308 individuals above the age of 60 were screened for medical issues and psychiatric illnesses. Those who fulfilled the intake criteria were evaluated using Subjective Memory Complaint Questionnaire (SMCQ), MOCA, ACE‐R or RUDAS and FAB. Serum B12 levels were evaluated for all the individuals.Result51.8 percent of individuals had normal cognitive function. The prevalence of cognitive impairment was 48.8%. Among these 42.3% of individuals had mild cognitive impairment. There was no significant correlation between MCI and Serum B12 levels in the screened population.ConclusionThere is a high prevalence of cognitive difficulties in the studied population.Dietary deficiency of Vitamin B12 does not appear to be a major factor contributing to the MCI. Alzheimer’s disease, vascular cognitive impairment and lifestyle and metabolic risk factors may need to be considered as contributory factors

Homocysteine, vitamin B12, folic acid levels and its association with Mild Cognitive Impairment in urban and rural dwelling Indians

AbstractBackgroundHomocysteine (Hcy) is a sulfur containing amino acid generated in the metabolism of methionine involving co‐factors such as B vitamins and folic acid. Deficiency of these co‐factors have been associated with increased Hcy levels (Hutto, 1997). Relationship between differing levels of plasma Hcy, vitamin B12, folic acid and cognitive impairment is inconclusive.MethodCross sectional analysis was done using the baseline data from two ongoing longitudinal studies such as Tata Longitudinal Study of Ageing (TLSA, N = 984) and Srinivaspura Aging, Neuro Senescence and COGnition (SANSCOG, N = 4404), an urban and rural cohorts (Sundarakumar et al, 2020) respectively. Hcy, vitamin B12, folic acid levels were compared between the subjects of both cohorts. Comparison of these levels between healthy and MCI (Mild Cognitive Impairment) subjects within and across the cohorts were done. CDR (Clinical Dementia Rating) scale was used to classify subjects having normal cognition and MCI, considering score of 0.5 as MCI. Mann‐Whitney U test was used to compare these levels between the groups.ResultHcy, vitamin B12, folic acid levels between the two cohorts showed significant difference, with higher levels of Hcy (median (IQR)) = (17.08 (11) vs 14.63 (10); p &lt;0.001), vitamin B12 (247 (252) vs 220 (143); p &lt;0.001) and folic acid (8.55 (9) vs 5.55(4); p &lt;0.05) in TLSA than SANSCOG. Significant difference seen in Hcy (17.73(11) vs 14.73 (10); p &lt;0.001), vitamin B12 (246 (249) vs 220 (136); p &lt;0.001) and folic acid (8.42 (9) vs 5.53 (4): p &lt;0.001) levels for healthy subjects between cohorts, higher levels were seen in TLSA subjects. Hcy (16.08 (8) vs 14.43 (12); p &lt;0.001) vitamin B12 (305 (341) vs 216 (174); p = 0.03) and folic acid (8.52 (9) vs 5.34 (4): p &lt;0.001) levels were significantly high in TLSA than SANSCOG for MCI subjects. However, these levels were not significantly different between healthy and MCI subjects within cohorts.ConclusionConsistently elevated levels of Hcy was observed in urban cohort. Though elevated level of Hcy was observed with normal vitamin B12 and folic acid, it was not associated with MCI.

The impacts of pharmacological drugs on vitamin B6, B9 and B12 intakes and levels among uk adults: National diet and nutrition survey rolling programme (NDNS) (2008–2017).

The impacts of pharmacological drugs on vitamin B6, B9 and B12 intakes and levels among uk adults: National diet and nutrition survey rolling programme (NDNS) (2008–2017).

Mild Dementia and the FIFA World Cup! A case report

AbstractBackgroundThe use of reminiscence therapy (RT) to prevent abnormal behaviors in patients with moderate dementia has been well‐established. It has many positive effects in the domains of quality of life, cognition, communication and mood. We are presenting a case where RT decreased abnormal behaviors.Method Case: An 83‐year‐old man with moderate dementia immigrated to the US. He lives with his family who provided care. No alcohol, tobacco use or illicit drug use was reported. The patient was evaluated by a geriatrician. The patient scored 12/30 in Montreal Cognitive Assessment indicating moderate cognitive impairment. Laboratory tests were unremarkable except Vitamin B12 level (slightly low 181). He was started on Donepezil and Vitamin B. Since his arrival to the US, the patient intermittently displayed abnormal behaviors including agitation, sleep disturbance and mood changes. Family members utilized his personal stories, hobbies and interests for behavioral interventions. A soccer‐focused RT method was applied. Several Youtube videos containing old matches during the FIFA World Cup were used whenever abnormal behavior was triggered.ResultFamily reports that the patient’s behaviors were relieved and interestingly improved using the soccer‐focused RT.ConclusionThis case report highlights the importance of a thorough evaluation of patients with dementia to include their life story and interests. In this case, behavioral modalities including RT were tried with considerable benefits. Technology‐based tools present a fertile land to explore regarding RT use in patients with moderate dementia.

Serum Vitamin B12 Level of Children and Its Clinical Relationship with Febrile Seizures

Serum Vitamin B12 Level of Children and Its Clinical Relationship with Febrile Seizures

Alzheimer’s Disease (AD): Vitamin B12 deficiency is associated with lower Mini‐Mental State Exam (MMSE) scores

AbstractBackgroundAlzheimer’s Disease (AD) is the leading cause of dementia in the elderly and several lines of evidence indicate that B12 hypovitaminosis is linked to AD. The biochemical pathways involved in AD that are affected by vitamin B12 are APP processing, Aβ fibrillization, Aβ‐induced oxidative damage as well as tau hyperphosphorylation and tau aggregation.Method103 outpatients with the diagnosis of AD conforming to criteria proposed by NINCDS‐ADRDA (2011), followed‐up at a public university hospital, had their vitamin B12 levels assessed and MMSE scores evaluated.Result91 patients (88,35%) presented vitamin B12 normal range (200 – 800 pg/mL) and 12 patients (11,65%) presented vitamin B12 deficiency (≤ 200 pg/mL). From the normal range group, 13 patients (14,29%) presented severe cognitive impairment (MMSE &lt; 10), 33 patients (36,26%) presented moderate cognitive impairment (MMSE = 10 – 20) and 45 patients (49,45%) presented mild cognitive impairment (MMSE &gt; 20). From the deficiency group, 2 patients (16,8%) presented severe cognitive impairment, 5 patients (41,6%) presented moderate cognitive impairment and 5 patients (41,6%) presented mild cognitive impairment. Both groups, vitamin B12 normal range and deficiency, had on average the same educational level: 2,91 and 3,42 years, respectively.ConclusionIn this sample of patients with AD, B12 hypovitaminosis is associated with lower MMSE scores when compared to vitamin B12 normal range.

Cardiometabolic Effects of Omnivorous vs Vegan Diets in Identical Twins

Increasing evidence suggests that, compared with an omnivorous diet, a vegan diet confers potential cardiovascular benefits from improved diet quality (ie, higher consumption of vegetables, legumes, fruits, whole grains, nuts, and seeds). To compare the effects of a healthy vegan vs healthy omnivorous diet on cardiometabolic measures during an 8-week intervention. This single-center, population-based randomized clinical trial of 22 pairs of twins (N = 44) randomized participants to a vegan or omnivorous diet (1 twin per diet). Participant enrollment began March 28, 2022, and continued through May 5, 2022. The date of final follow-up data collection was July 20, 2022. This 8-week, open-label, parallel, dietary randomized clinical trial compared the health impact of a vegan diet vs an omnivorous diet in identical twins. Primary analysis included all available data. Twin pairs were randomized to follow a healthy vegan diet or a healthy omnivorous diet for 8 weeks. Diet-specific meals were provided via a meal delivery service from baseline through week 4, and from weeks 5 to 8 participants prepared their own diet-appropriate meals and snacks. The primary outcome was difference in low-density lipoprotein cholesterol concentration from baseline to end point (week 8). Secondary outcome measures were changes in cardiometabolic factors (plasma lipids, glucose, and insulin levels and serum trimethylamine N-oxide level), plasma vitamin B12 level, and body weight. Exploratory measures were adherence to study diets, ease or difficulty in following the diets, participant energy levels, and sense of well-being. A total of 22 pairs (N = 44) of twins (34 [77.3%] female; mean [SD] age, 39.6 [12.7] years; mean [SD] body mass index, 25.9 [4.7]) were enrolled in the study. After 8 weeks, compared with twins randomized to an omnivorous diet, the twins randomized to the vegan diet experienced significant mean (SD) decreases in low-density lipoprotein cholesterol concentration (-13.9 [5.8] mg/dL; 95% CI, -25.3 to -2.4 mg/dL), fasting insulin level (-2.9 [1.3] μIU/mL; 95% CI, -5.3 to -0.4 μIU/mL), and body weight (-1.9 [0.7] kg; 95% CI, -3.3 to -0.6 kg). In this randomized clinical trial of the cardiometabolic effects of omnivorous vs vegan diets in identical twins, the healthy vegan diet led to improved cardiometabolic outcomes compared with a healthy omnivorous diet. Clinicians can consider this dietary approach as a healthy alternative for their patients. ClinicalTrials.gov Identifier: NCT05297825.