Vitamin D

Previous meta-analyses reported inconsistent results on the effect of vitamin D on depression because of different baseline concentrations of 25-hydroxyvitamin D [25(OH)D], highlighting the need for a more accurate subgroup analysis of previously published findings. The goal of the present study was to evaluate the effect of vitamin D supplementation on depression in adults.

A systematic search in numerous databases including PubMed, Embase, and Web of Science was performed. Randomized-controlled trials comparing the effect of vitamin D on depression in adults were selected.

Eighteen studies met the inclusion criteria in the retrieved citations. The meta-analysis showed that vitamin D supplementation had a significant effect on overall reduction in depression symptom scores (SMD = −0.15, 95 % CI [−0.26, −0.04]). Sub-group analysis showed that vitamin D supplementation significantly reduced depressive symptom scores in patients with serum 25(OH)D levels higher than 50 nmol/L (SMD = −0.38, 95 % CI [−0.68, −0.08]).

Vitamin D supplementation has a benefit on improving depressive symptoms in adults with primary depression and 25(OH)D levels higher than 50 nmol/L but has no effect on improving depressive symptoms in adults with primary depression and 25(OH)D levels lower than 50 nmol/L. Relatively high levels of 25(OH)D maybe required for alleviating depression.

The randomized studies included in this study were designed and completed at different times and countries, the variability in duration and dose of vitamin D supplementation may have introduced significant heterogeneity and have militated against observation of the effects of vitamin D supplementation on depression.

We discuss, with a biocultural perspective, the connection between living condition related to the Great Peasants’ Revolt and health status of the nonadult population from the 16th century North-eastern Italy, with a particular focus on those caused by micronutrients C and D. We analysed forty-one skeletons of nonadults in primary deposition with macroscopic examination coupled with a literature review aimed at providing a differential diagnosis. Eleven nonadults present probable cases of rickets, twelve show evidence that seems to be related to scurvy, while ten individuals feature a pattern consistent with a co-occurrence condition. Finally, eight subjects have no pathological changes or evidence, and that may be considered strictly related to C or D deficiency.

This study provides a significant example of pathological lesion on nonadults coming from the same area and framed in a limited chronological period. In addition, the sample is distinguished by the number of subjects and the good preservation of their bone tissue. Finally, the work is of primary importance as the Italian panorama lacks exhaustive paleopathological publications.

We conducted a meta-analysis to review the effects of vitamin D supplementation during pregnancy on neonatal 25-hydroxyvitamin D (25(OH)D) and calcium concentrations. Randomized controlled trials that supplemented subjects with vitamin D₂ or D₃ during pregnancy and reported cord blood 25(OH)D or calcium concentrations were included. A random-effect model was used to pool the data. Subgroup analyses were performed to explore the sources of heterogeneity. We searched PubMed, Web of Science, and Cochrane Library for relevant publications. Among 1768 publications identified by our search strategy, 13 studies met our inclusion criteria. Cord blood 25(OH)D concentration was significantly increased by maternal vitamin D supplementation (mean difference, 22.48 nmol/L; 95% confidence interval, 15.90-29.06 nmol/L) with high heterogeneity (I² = 98.8%, P < .0001). No effects on cord blood calcium concentration was reported (mean difference, 0.05 mmol/L; 95% confidence interval, −0.04-0.13 mmol/L). Supplementation regimens and the different control groups may be the major sources of heterogeneity. Vitamin D supplementation during pregnancy can improve cord blood 25(OH)D concentration in women with low 25(OH)D concentration, but does not affect cord blood calcium concentration. Future researches are needed to evaluate the effect of maternal vitamin D supplementation in women with a normal 25(OH)D concentration and explore the combined effects of vitamin D, calcium, and multivitamins.

Associations between documented sun-exposure, exercise patterns and fish and supplement intake and 25-hydroxyvitamin D (25OHD) and parathyroid hormone (PTH) were investigated in a random household survey of Macau residents (aged 18–93). Blood samples (566) taken in summer were analyzed for 25OHD and PTH.

In this Chinese population, 55% were deficient (25OHD  < 50 nmol/L: median (interquartile range) = 47.7 (24.2) nmol/L). Vitamin D deficiency was greatest in those aged <50 years: median (interquartile range) = 43.3 (18.2) nmol/L, females: median (interquartile range) = 45.5 (19.4) nmol/L and those with higher educational qualifications: median (interquartile range) = 43.1 (18.7) nmol/L.

In the total Macau population, statistically significant (p < 0.01) modifiable associations with lower 25OHD levels were sunlight exposure (β = 0.06), physical activity (PA) (measured as hours(hrs)/day: β = 0.08), sitting (measured as hrs/day β = −0.20), intake of fish (β = 0.08) and calcium (Ca) supplement intake (β = 0.06) [linear regression analysis adjusting for demographic risk factors]. On similar analysis, and after adjustment for 25OHD, the only significant modifiable associations in the total population with PTH were sitting (β = −0.17), Body Mass Index (β = 0.07) and Ca supplement intake (β = −0.06).

In this Macau population less documented sun exposure, fish and Ca supplement intake and exercise were associated with lower 25OHD levels, especially in the younger population, along with the interesting finding that more sitting was associated with both lower 25OHD and high PTH blood levels.

In conclusion, unlike findings from Caucasian populations, younger participants were significantly more vitamin D deficient, in particular highly educated single females. This may indicate the desire of young females to be pale and avoid the sun. There are also big differences in lifestyle between the older generation and the younger, in particular with respect to sun exposure and PA.

This article is part of a Special Issue entitled '17th Vitamin D Workshop'.

Observational studies have linked vitamin D status and infectious disease. This association is supported by the presence of the vitamin D receptor and CYP27B1 in immune cells. This review aims to consolidate data from clinical trials that used vitamin D for the treatment or prevention of infectious disease.

The authors searched the term "(vitamin D OR ergocalciferol OR cholecalciferol OR vitamin D2 OR vitamin D3 OR calcitriol) AND (infection OR tuberculosis OR sepsis OR pneumonia)" with limits preset to manuscripts published in English and with human subjects. They identified controlled trials that measured infectious outcomes (eg, incidence and severity of disease, time to disease resolution or recurrence, measures of clinical improvement, mortality). Studies that used analog, topical or micronutrient formulations of vitamin D, assessed only vitamin D status or lacked a comparison group were excluded. The references from eligible manuscripts and from 2 recent reviews were scanned for additional manuscripts.

One thousand two hundred eighty-four manuscripts were identified with our search terms, with 60 papers still eligible after review of the title and abstract. Full review of these papers, their references and 2 related reviews yielded 38 manuscripts.

Although some prospective studies show positive results regarding vitamin D on infectious disease, several robust studies are negative. Factors such as high variability between studies, the difference in individual responsiveness to vitamin D and study designs that do not primarily investigate infectious outcomes may mask the effects of vitamin D on infections.

This article is part of a Special Issue “Chemosignals and Reproduction”.

Many lizards have diverse glands that produce chemosignals used in intraspecific communication and that can have reproductive consequences. For example, information in chemosignals of male lizards can be used in intrasexual competition to identify and assess the fighting potential or dominance status of rival males either indirectly through territorial scent-marks or during agonistic encounters. Moreover, females of several lizard species “prefer” to establish or spend more time on areas scent-marked by males with compounds signaling a better health or body condition or a higher genetic compatibility, which can have consequences for their mating success and inter-sexual selection processes. We review here recent studies that suggest that the information content of chemosignals of lizards may be reliable because several physiological and endocrine processes would regulate the proportions of chemical compounds available for gland secretions. Because chemosignals are produced by the organism or come from the diet, they should reflect physiological changes, such as different hormonal levels (e.g. testosterone or corticosterone) or different health states (e.g. parasitic infections, immune response), and reflect the quality of the diet of an individual. More importantly, some compounds that may function as chemosignals also have other important functions in the organism (e.g. as antioxidants or regulating the immune system), so there could be trade-offs between allocating these compounds to attending physiological needs or to produce costly sexual “chemical ornaments”. All these factors may contribute to maintain chemosignals as condition-dependent sexual signals, which can inform conspecifics on the characteristics and state of the sender and allow making behavioral decisions with reproductive consequences. To understand the evolution of chemical secretions of lizards as sexual signals and their relevance in reproduction, future studies should examine what information the signals are carrying, the physiological processes that can maintain the reliability of the message and how diverse behavioral responses to chemosignals may influence reproductive success.