Relationship between intake and plasma concentrations of vitamin B12 and folate in 873 adults with a physically active lifestyle: a cross-sectional study

A Framework to Guide Defining an Upper Threshold of Crystalline Vitamin B12 in Foods and Food Supplements

PURPOSE OF REVIEW

To define an intake threshold of vitamin B12 from food supplements that is sufficient to maintain normal body functions, but it does not cause pharmacological effects.

RECENT FINDINGS

We used studies on the amount of B12 absorbed following oral B12 application and non-comparative case-series studies to synthesize evidence on pharmacological effects of oral B12 (between < 10 µg and 3000 µg) in people with manifested deficiency. There is a dose-dependent intestinal absorption of B12 and in the same time effects on body metabolism and functions. Food supplements providing ≤ 20 µg B12 daily are unlikely to cause pharmacological effects, while 50 µg might correct abnormal biochemical markers in some deficient patients. Foods for special medical purposes for people who cannot absorb B12 may contain 100 µg to 150 µg B12. This dose may ensure 1-4 µg of the vitamin reaching the circulation on a daily basis independent of intrinsic factor. Dosages ≥ 200 µg/d should be considered as drugs that can correct anemia, metabolic markers and clinical symptoms. The content of vitamin B12 in food supplements should not exceed 20 µg. In addition, people with deficiency should receive appropriate medical treatment with high dose B12.

R. S, Bhat MA, Kar S, Mahanta BN, Mathew JL, Nair S, Singh CM, Singh K, Thekkumkara Surendran A. Association of dietary intake with micronutrient deficiency in Indian school children: a cross-sectional study

Adequate nutrition is necessary during childhood and early adolescence for adequate growth and development. Hence, the objective of the study was to assess the association between dietary intake and blood levels of minerals (calcium, iron, zinc, and selenium) and vitamins (folate, vitamin B12, vitamin A, and vitamin D) in urban school going children aged 6-16 years in India, in a multicentric cross-sectional study. Participants were enrolled from randomly selected schools in ten cities. Three-day food intake data was collected using a 24-h dietary recall method. The intake was dichotomised into adequate and inadequate. Blood samples were collected to assess levels of micronutrients. From April 2019 to February 2020, 2428 participants (50⋅2 % females) were recruited from 60 schools. Inadequate intake for calcium was in 93⋅4 % (246⋅5 ± 149⋅4 mg), iron 86⋅5 % (7⋅6 ± 3⋅0 mg), zinc 84⋅0 % (3⋅9 ± 2⋅4 mg), selenium 30⋅2 % (11⋅3 ± 9⋅7 mcg), folate 73⋅8 % (93⋅6 ± 55⋅4 mcg), vitamin B12 94⋅4 % (0⋅2 ± 0⋅4 mcg), vitamin A 96⋅0 % (101⋅7 ± 94⋅1 mcg), and vitamin D 100⋅0 % (0⋅4 ± 0⋅6 mcg). Controlling for sex and socioeconomic status, the odds of biochemical deficiency with inadequate intake for iron [AOR = 1⋅37 (95 % CI 1⋅07-1⋅76)], zinc [AOR = 5⋅14 (95 % CI 2⋅24-11⋅78)], selenium [AOR = 3⋅63 (95 % CI 2⋅70-4⋅89)], folate [AOR = 1⋅59 (95 % CI 1⋅25-2⋅03)], and vitamin B12 [AOR = 1⋅62 (95 %CI 1⋅07-2⋅45)]. Since there is a significant association between the inadequate intake and biochemical deficiencies of iron, zinc, selenium, folate, and vitamin B12, regular surveillance for adequacy of micronutrient intake must be undertaken to identify children at risk of deficiency, for timely intervention.

Relationship between high dose intake of vitamin B12 and glaucoma: Evidence from NHANES 2005-2008 among United States adults

Objective

Glaucoma has currently become the second leading cause of blindness in the world. Serum vitamin B12 level has been found to be involved in the development and progression of glaucoma. We performed the present study to confirm this association.

Methods

This cross-sectional study included 594 participants aged 40 years and older in the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2008. Retinal imaging was performed using the Ophthalmic Digital Imaging system (Retinography) to assess the retina for the presence of features of glaucomatous lesions. Logistic regression models were used to assess the association between dietary vitamin intake and glaucoma.

Results

After screening, 594 subjects were finally included. Among all vitamin intakes, we observed significant differences between the two groups for vitamin B12 intake (5.93 vs. 4.77 mg, p = 0.033). According to the logistic regression results, the intake of vitamin B12 was significantly positively associated with glaucoma (model 1: OR = 1.078, 95% CI = 1.019-1.141; model 2: OR = 1.092, 95% CI = 1.031-1.158; model 3: OR = 1.092, 95% CI = 1.029-1.158). After performing a quantile regression, we observed a significant positive association between vitamin B12 intake and incident glaucoma in the fourth quartile (model 1: OR = 1.133, 95% CI = 1.060-1.210; model 2: OR = 1.141, 95% CI = 1.072-1.215; model 3: OR = 1.146, 95% CI = 1.071-1.226).

Conclusions

Therefore, the above results, high-dose intake of vitamin B12 may promote the development of glaucoma.

The association between B vitamins and the risk of COVID-19

The fast spread of the coronavirus disease 2019 (COVID-19) epidemic and its high mortality were quickly noticed by the health community. B vitamins are essential micronutrients for the body with antioxidant, anti-inflammatory and immune-regulating properties. The present study can provide a comprehensive picture of the associations between B vitamins and COVID-19 incidence. This study was undertaken on 9189 adult participants of the Yazd Health Study (YaHS) and Taghzieh Mardom-e-Yazd (TAMIZ) study aged 20 to 69 years. Data on dietary intakes were obtained using a validated FFQ. Multivariable logistic regression analysis was used to evaluate the association between B vitamins and COVID-19. Our findings indicated that participants in the fourth quartile of vitamin B₅ intake compared with the first quartile had a protective effect against COVID-19 (OR: 0·53, 95 % CI 0·28, 0·99, P-trend = 0·02) after adjustment for all possible confounds in model 3. In addition, participants in the third quartile of vitamin B₁₂ intake compared with the first quartile (OR: 0·63, 95 % CI 0·40, 0·98, P-trend = 0·11) had fewer odds of COVID-19 after full adjustments for confounders. Our findings indicated no significant relationship between dietary intake of vitamin B₁, B₂, B₃, B₉ and B-complex and COVID-19. A higher intake of vitamin B₅ could reduce the odds of COVID-19 by 47 %, and a moderate intake of vitamin B₁₂ had a protective effect on COVID-19. Although our study has promising results, stronger clinical studies are needed.

Prevalence of specific micronutrient deficiencies in urban school going children of India aged between 6 and 16 years: study protocol for a multicentric cross-sectional study

INTRODUCTION

Childhood and adolescence are the period of rapid physical and cognitive growth and development, requiring adequate nutrition. Malnutrition in the form of undernutrition or micronutrient deficiency or overweight/obesity affects the health, cognition and educational achievement of this age group. The objective of this study is to assess the prevalence of calcium, iron, zinc, selenium, folate, vitamin A, 25 hydroxy vitamin D and vitamin B12 deficiencies in the serum and haemoglobin, ferritin and lead levels and its association with reported dietary intake and cognitive abilities, in urban school going children aged 6-16 years in 10 cities of India.

METHODS AND ANALYSIS

A multicentric cross-sectional study will be conducted to recruit 2400 participants (240 per site) across India. Participants will be selected using random sampling and will be categorised into age groups of 6-11 years and 12-16 years, with equal distribution. Data on socioeconomic status, anthropometric measures and 3-day dietary intake and cognitive performance will be collected. Blood samples will be collected for biochemical analysis of micronutrients. Findings will estimate the prevalence of micronutrient deficiencies and their association with dietary habits and cognitive functioning.

ETHICS AND DISSEMINATION

Study protocol has been reviewed and approved by institutional ethics committee of all 10 participating sites. Results will be shared and published in a peer-reviewed journal, so that the findings will be helpful for the stakeholders in planning nutritional interventions for targeted groups.

TRIAL REGISTRATION NUMBER

CTRI/2019/02/017783.

Relationship between intake and plasma concentrations of vitamin B12 and folate in 873 adults with a physically active lifestyle: a cross-sectional study

BACKGROUND

Vitamin B12 and folate function as co-factors in pathways used during physical activity. Physical activity may therefore increase vitamin requirements, leading to a risk of deficient plasma concentrations. We aimed to investigate the relationship between intake and plasma concentrations of vitamin B12 and folate in physically active adults, as well as identify other determinants of vitamin B12 and folate plasma concentrations.

METHODS

The study population consisted of 873 adults (528 men and 345 women), aged 19-78 years, who participated in a 4-day walking event. The relationship between intake and plasma concentrations of vitamin B12 and folate was assessed using correlation and linear regression analyses. In addition, potential other determinants (sex, age, body mass index, energy intake and physical activity) of vitamin plasma concentrations were investigated.

RESULTS

Significant positive correlations were observed between intake and plasma concentrations of vitamin B12 [Pearson's correlation coefficient = 0.15; 95% confidence interval (CI) = 0.08-0.21] and folate (Pearson's correlation coefficient = 0.18; 95% CI = 0.12-0.25). In addition to vitamin intake, sex, age and energy intake were also determinants of both vitamin B12 and folate plasma concentrations in multivariable regression models.

CONCLUSIONS

The results suggest a positive association between intake and plasma concentrations for both vitamin B12 and folate in physically active people. By contrast to our hypothesis, physical activity was not a determinant of vitamin B12 and folate plasma concentrations. However, sex, age and energy intake were found to be determinants. Thus, when studying the relationship between intake and plasma concentrations of vitamin B12 or folate, these factors should be taken into account.