The inverse association between serum 25-hydroxyvitamin D and mortality may be modified by vitamin A status and use of vitamin A supplements

Association between fat-soluble vitamins and metabolic syndromes in US adults: a cross-section study from NHANES database

BACKGROUND

Previous studies have shown significant associations between individual fat-soluble vitamins (FSVs) and metabolic syndromes (MetS). However, evidence on the multiple FSVs co-exposure and MetS odds is limited. Given that individuals are typically exposed to different levels of FSVs simultaneously, and FSVs can interact with each other. It's necessary to explore the association between multiple FSVs co-exposure and MetS odds. This study aims to address this gap in general U.S. adults aged ≥ 20 years.

METHODS

We conducted a cross-sectional study utilizing data from the National Health and Nutrition Examination Surveys (NHANESs) 2003-2006 and 2017-2018. Three FSV, including vitamin A (VA), vitamin E (VE), and vitamin D (VD), and MetS diagnosed according to the ATP III guidelines were selected as exposure and outcome, respectively. Multivariable-adjusted logistic model was used to explore the associations of individual FSV exposure with MetS odds and MetS components. Restricted cubic splines were performed to explore the dose-response relationships among them. The quantile g-computation method was adopted to explore the associations of multiple FSVs co-exposure with MetS odds and MetS components.

RESULTS

The presented study included a total of 13,975 individuals, with 2400 (17.17%) were diagnosed with MetS. After adjusting for various confounders, a positive linear pattern was observed for serum VA and VE and MetS associations. Serum VD was found to be negatively associated with MetS in a linear dose-response way. For each component of MetS, higher serum VA and VE were associated with higher triglyceride and high-density lipoprotein; higher serum VD was negatively associated with triglyceride, blood pressure, and fasting plasma glucose. MetS odds increased by 15% and 13%, respectively, in response to one quartile increase in FSVs co-exposure index (qgcomp) in the conditional model (OR = 1.15, 95%CI: 1.06, 1.24) and the marginal structural model (OR = 1.13, 95%CI: 1.06, 1.20). Besides, co-exposure to VA, VE, and VD was positively associated with triglyceride, high-density lipoprotein, and blood pressure levels.

CONCLUSION

Findings in the present study revealed that high serum VA and VE levels were associated with elevated MetS odds, while serum VD was inversely associated with MetS odds. FSVs co-exposure was positively associated with MetS odds.

Dysregulated serum concentrations of fat-soluble vitamins in dogs with chronic enteropathy

BACKGROUND

In inflammatory bowel disease (IBD) of humans, nutrient malabsorption can result in fat-soluble vitamin deficiency, especially of vitamin D. In veterinary species, decreased concentrations of vitamin D are relatively common in dogs with chronic enteropathy (CE), but data on the status of other fat-soluble vitamins (FSVs) is lacking.

OBJECTIVES

Determine the serum concentrations of retinol, vitamin D, and α-tocopherol in dogs with CE compared with healthy dogs and compare clinical, clinicopathologic variables between CE and healthy dogs to detect associations with decreased FSVs concentrations.

ANIMALS

Eighteen client-owned dogs with CE and 33 healthy dogs.

METHODS

Serum 25-hydroxyvitamin D (25[OH]D), serum retinol and α-tocopherol concentrations were compared between groups. Correlations and multiple regression modeling were used to examine the relationship between serum 25(OH)D, retinol, and α-tocopherol concentrations and clinical and clinicopathological variables.

RESULTS

Dogs with low serum albumin concentrations were more likely to have lower 25(OH)D concentrations than dogs with normal serum albumin concentration. Dogs with CE had higher serum concentrations of retinol, and variable α-tocopherol concentrations. The cause of these dysregulated vitamin concentrations is unclear and requires further study.

CONCLUSION AND CLINICAL IMPORTANCE

Dogs with severe forms of CE should be monitored for decreased concentrations of 25(OH)D. Additional studies are needed to evaluate the clinical relevance and the possible benefit of vitamin D supplementation in these patients.

Predictors of 25-hydroxyvitamin D concentrations during pregnancy: A longitudinal analysis in the Brazilian Amazon

OBJECTIVES

To determine predictors of 25-hydroxyvitamin D₃ (25(OH)D₃) concentrations (25^th, 50^th, and 75^th percentiles) in the third trimester of pregnancy.

SUBJECTS/METHODS

Data on sociodemographic, obstetric, lifestyle and pregnancy characteristics, including serum 25(OH)D₃ and retinol, were collected among 448 pregnant women who participated in the Maternal and Child Health and Nutrition in Acre, Brazil (MINA-Brazil Study) in Cruzeiro do Sul, Brazilian Amazon (latitude 7°S). Simultaneous-quantile regression was fitted to prospectively assess predictors at the 25^th, 50^th and 75^th percentiles of 25(OH)D₃ concentrations.

RESULTS

In the third trimester, 25(OH)D₃ <50 nmol/L was observed in 26% of pregnant women. Exposure to the Amazonian dry season during follow-up and vitamin D status ≥75 nmol/L in the second trimester of pregnancy were positively associated with 25(OH)D₃ concentrations in the third trimester. Pregnant women who were the main providers of family income presented lower 25(OH)D₃ concentrations (50^th and 75^th percentiles: -15 nmol/L, 95%CI -24; -3, p = 0.02, and -22 nmol/L, 95%CI -36; -7, p = 0.004, respectively), as well as those with sustained vitamin A insufficiency (25^th and 50^th percentiles: -27 nmol/L, 95%CI -40; -15, p < 0.001, and -17 nmol/L, 95%CI -33; -1, p = 0.04, respectively). Sun protection practices had a smaller negative impact on 25(OH)D₃, restricted to participants whose concentrations were at the 25^th percentile of the distribution.

CONCLUSIONS

Seasonality and vitamin A status were important predictors of 25(OH)D₃ concentrations in the third trimester. Adequate exposure to sunlight and dietary sources of vitamin A within safe intake levels may help ensuring a good nutritional status of vitamin D during pregnancy.

Multiple vitamin co-exposure and mortality risk: A prospective study

BACKGROUND & AIMS

Existing epidemiological studies explored the associations of circulating vitamins and mortality focusing on individual vitamin effects, and controversial findings were obtained. The joint effects of multiple vitamin co-exposure are worth studying. The study aimed to elucidate the associations of circulating vitamins and the joint effects of these vitamins' co-exposure with all-cause and cause-specific mortality risks.

METHODS

We prospectively evaluated the associations of the concentrations of six kinds of vitamins (A, D, E, C, B12 and B9) in serum with risks for all-cause and cause-specific mortalities among U.S. adults. Mortality status and cause of death were determined by NHANES-linked public available files dated up to 31 December 2015. An unsupervised K-means clustering method was used to cluster the participants into several vitamin co-exposure patterns. The Cox proportional hazards model was used for statistical analysis.

RESULTS

A total of 1404 deaths occurred during a median of 10.9 years follow-up among 8295 participants. In multivariable adjustment, increasing levels of vitamin D were associated with reduced all-cause and cause-specific mortality risks. A J-shaped nonlinear exposure-response relationship was observed between all studied vitamins (except for vitamin D) and all-cause mortality risk. Four co-exposure patterns were generated based on the studied vitamins, as follows: low-level exposure (cluster 1), vitamin A/D exposure (cluster 2), water-soluble vitamin exposure (cluster 3) and high-level exposure (cluster 4). Compared with those in cluster 1, participants in cluster 2 had lower all-cause and cancer mortality risks, with hazard ratios (95% confidence intervals [CIs]) of 0.67 (0.53, 0.85) and 0.45 (0.29, 0.71), respectively.

CONCLUSIONS

The findings in this study indicated that high circulating vitamin D levels were associated with reduced mortality risk among U.S. adults. Vitamin co-exposure at moderate levels appropriately contributed to low all-cause and cancer mortality risks. Our findings provided a novel perspective for exploring the joint health effects of multivitamin co-exposure. Future investigations are needed to further unravel the underlying mechanisms of possible vitamin interactions.

Basal Vitamin D Status and Supplement Dose Are Primary Contributors to Maternal 25-Hydroxyvitamin D Response to Prenatal and Postpartum Cholecalciferol Supplementation

BACKGROUND

Variability in the 25-hydroxyvitamin D [25(OH)D] response to prenatal and postpartum vitamin D supplementation is an important consideration for establishing vitamin D deficiency prevention regimens.

OBJECTIVES

We aimed to examine interindividual variation in maternal and infant 25(OH)D following maternal vitamin D supplementation.

METHODS

In a randomized trial of maternal vitamin D supplementation (Maternal Vitamin D for Infant Growth Trial), healthy pregnant women (n = 1300) received a prenatal cholecalciferol (vitamin D-3) dose of 0, 4200, 16,800, or 28,000 IU/wk from 17 to 24 wk of gestation followed by placebo to 6 mo postpartum. A fifth group received 28,000 IU cholecalciferol/wk both prenatally and postpartum. In a subset of participants, associations of 25(OH)D with hypothesized explanatory factors were estimated in women at delivery (n = 655) and 6 mo postpartum (n = 566), and in their infants at birth (n = 502) and 6 mo of age (n = 215). Base models included initial 25(OH)D and supplemental vitamin D dose. Multivariable models were extended to include other individual characteristics and specimen-related factors. The model coefficient of determination (R2) was used to express the percentage of total variance explained.

RESULTS

Supplemental vitamin D intake and initial 25(OH)D accounted for the majority of variance in maternal 25(OH)D at delivery and postpartum (R2 = 70% and 79%, respectively). Additional characteristics, including BMI, contributed negligibly to remaining variance (<5% increase in R2). Variance in neonatal 25(OH)D was explained mostly by maternal delivery 25(OH)D and prenatal vitamin D intake (R2 = 82%). Variance in 25(OH)D in later infancy could only partly be explained by numerous biological, sociodemographic, and laboratory-related characteristics, including feeding practices (R2 = 43%).

CONCLUSIONS

Presupplementation 25(OH)D and vitamin D supplemental dose are the major determinants of the response to maternal prenatal vitamin D intake. Vitamin D dosing regimens to prevent maternal and infant vitamin D deficiency should take into consideration the mean 25(OH)D concentration of the target population.

Are plasma 25-hydroxyvitamin D and retinol levels and one-carbon metabolism related to metabolic syndrome in patients with a severe mental disorder?

There is a scarcity of studies assessing the influence of biomarkers in metabolic syndrome in psychiatric patients. Our aim was to correlate serum or plasma levels of 25-hydroxyvitamin D (25-OH-VD), retinol, vitamin B12 (VB12), folate and homocysteine (Hcy), with the metabolic status, in a sample of 289 outpatients with Schizophrenia or Bipolar Disorder. Logistic regression and multiple linear regressions were performed to assess the ability of biomarkers to predict the presence of MetS, the number of risk factors for MetS, and insulin resistance indexes (HOMA and QUICKI). Regarding the association between biomarkers and the QUICKI index, the model explained 6.8% of the variance, with folate and 25-OH-VD levels contributing significantly to the model. The model predicting the number of MetS risk factors was significant and explained 21.7% of the variance, being 25-OH-VD and retinol the statistically significant factors. As for the impact of biomarkers on MetS, the model was statistically significant, being 25-OH-VD and retinol levels the significant factors.  We report for the first time an association between MetS and both low 25-OH-VD and high retinol concentrations. Inflammation-related biomarkers may help identify patients with a high risk of MetS who might benefit from healthy lifestyle counselling and early intervention.

Vitamin D Status and Mortality: A Systematic Review of Observational Studies

Epidemiological evidence suggests that vitamin D deficiency is associated with increased mortality, but it is unclear whether this is explained by reverse causation, and if there are specific causes of death for which vitamin D might be important. We conducted a systematic review of observational studies investigating associations between circulating 25-hydroxyvitamin D (25(OH)D) concentration and all-cause or cause-specific mortality in generally healthy populations. Relevant studies were identified using PubMed and EMBASE searches. After screening 722 unique records and removing those that were ineligible, 84 articles were included in this review. The vast majority of studies reported inverse associations between 25(OH)D concentration and all-cause mortality. This association appeared to be non-linear, with progressively lower mortality with increasing 25(OH)D up to a point, beyond which there was no further decrease. There is moderate evidence that vitamin D status is inversely associated with cancer mortality and death due to respiratory diseases, while for cardiovascular mortality, there is weak evidence of an association in observational studies, which is not supported by the data from intervention or Mendelian randomization studies. The relationship between vitamin D status and other causes of death remains uncertain due to limited data. Larger long-term studies are required to clarify these associations.

The Role of Vitamins in the Pathogenesis of Non-alcoholic Fatty Liver Disease

The incidence of non-alcoholic fatty liver disease (NAFLD) is rising rapidly in parallel with obesity rates. The underlying pathogenesis of NAFLD remains an enigma but is largely influenced by individual lifestyle choices involving diet and exercise. Therefore, studies have highlighted the importance of calorie reduction and macronutrient composition (eg, carbohydrate and fat) in modifying disease outcomes. Micronutrients are also believed to play a role in disease progression. There are now an increasing number of studies linking vitamins with NAFLD, particularly vitamin E, and the supplementation of several different vitamins has been demonstrated as a promising therapeutic option in the treatment of NAFLD. This review provides a broad overview of the potential role of vitamins in NAFLD development and disease management.