Association of seasonality and serum albumin concentration with vitamin D deficiency in subjects with chronic hepatitis C infection living in a sunny country

The Variability of Vitamin D Concentrations in Short Children with Short Stature from Central Poland-The Effects of Insolation, Supplementation, and COVID-19 Pandemic Isolation

The aim of the study was to investigate the effects of seasonal variability of insolation, the implementation of new recommendations for vitamin D supplementation (2018), and the SARS-CoV-2 pandemic lockdown (2020) on 25(OH)D concentrations in children from central Poland. The retrospective analysis of variability of 25(OH)D concentrations during the last 8 years was performed in a group of 1440 children with short stature, aged 3.0-18.0 years. Significant differences in 25(OH)D concentrations were found between the periods from mid-2014 to mid-2018, from mid-2018 to mid-2020, and from mid-2020 to mid-2022 (medians: 22.9, 26.0, and 29.9 ng/mL, respectively). Time series models created on the grounds of data from 6 years of the pre-pandemic period and used for prediction for the pandemic period explained over 80% of the seasonal variability of 25(OH)D concentrations, with overprediction for the first year of the pandemic and underprediction for the second year. A significant increase in 25(OH)D concentrations was observed both after the introduction of new vitamin D supplementation guidelines and during the SARS-CoV-2 pandemic; however, the scale of vitamin D deficiency and insufficiency was still too high. Time series models are useful in analyzing the impact of health policy interventions and pandemic restrictions on the seasonal variability of vitamin D concentrations.

Variability in response to vitamin D supplementation according to vitamin D metabolism related gene polymorphisms in healthy adults

OBJECTIVE

The aim of this study was to determine the influence of polymorphisms in some key gene actors of the vitamin D (vitD) metabolic pathway on supplementation efficacy.

METHODS

In total, 245 healthy participants were recruited from occupational medicine service in Sahloul University Hospital with vitD deficiency [25(OH)D ≤ 30 ng/ml]. After giving an informed consent, all participants were asked to complete a generalized questionnaire and to follow a detailed personalized supplementation protocol. Genetic study was performed by PCR-RFLP for 15 single nucleotide polymorphisms (SNPs) belonging to DBP, CYP2R1, CYP27B14, CYP24A1 and VDR genes. Statistical study was carried out with SPSS23.0.

RESULTS

Among the studied SNPs, non-response was significantly associated with variant alleles of rs4588 (OR* = 11.51; p < 0.001), rs10766197 (OR* = 6.92; p = 0.008) and rs12794714 (OR* = 5.09; p = 0.004). These three SNPs contributed in 18.8% in response variability with rs4588 being the most influential (10.3%). There was a significant linear negative correlation between baseline 25(OH)D and post supplementation 25(OH)D concentration (r = -0.437; p < 0.001) as well as a linear negative association between the increase in 25(OH)D concentration and GRS (GRS: genetic risk score = the sum of risk alleles) (r = -0.149; p = 0.033).

CONCLUSIONS

DBP-rs4588, CYP2R1-rs10766197 and rs12794714 variants are associated with variations in serum 25(OH)D concentrations and efficacy of response to vitD supplementation in Tunisian adults. Taking into account these variations can help to better adapt vitD intake to ensure a higher response to supplementation.

Plasma 25-hydroxyvitamin D levels, quality of life, inflammation and depression in older adults: Are they related?

BACKGROUND AND OBJECTIVES

This study aimed to determine whether there is an association between inflammation and depression taking into account the effect of several confounders, but specially plasma 25-hydroxyvitamin D (25[OH]D) levels.

MATERIAL AND METHODS

A cross-sectional study was conducted on adults (n = 346) aged 60 years or older recruited from primary healthcare centres. Depression was assessed by the Geriatric Depression Scale (GDS), while plasma 25(OH)D and inflammatory cytokines were measured following routine biochemical laboratory protocols.

RESULTS

Subjects were divided into two subgroups according to their depression status, and matched in their baseline conditions using random forest-based propensity scores. Both groups were rather similar in regard to most variables, apart from quality of life (p < 0.001) and plasma levels of IL-6 (p = 0.03). The overall prevalence of vitamin D deficiency was 36.3% (95% Confidence Interval [95% CI], 30.2%-42.5%), without a significant difference between depression groups (p = 0.2). A significant association was observed between GDS score and plasma IL-6 levels only among those with SF-6D score between 0.26 and 0.50 (p = 0.001).

CONCLUSIONS

The association between inflammation and depression is more likely to be due to a moderation influence of quality of life rather than plasma 25(OH)D levels. However, further studies are needed to ascertain the effect of a poor quality of life leading to chronic inflammation and poor health upon longer periods of follow-up.