The role of vitamin D in adipogenesis

Vitamin D, a secosteroid predominately obtained by endogenous production, has in recent years been linked to obesity and its comorbidities. The purpose of this review is to draw conclusions from animal and human studies on the effects of vitamin D on adipogenesis to identify the molecular links between vitamin D and obesity. The information presented herein was obtained from 4 databases (PubMed, CINAHL, Cochrane Library, Scopus) using predefined search terms, as well as research literature and other reviews. The effects of vitamin D on adipogenesis have been researched in several animal models, and the majority of these studies suggest vitamin D plays an inhibitory role in adipogenesis. Studies into vitamin D status and obesity in humans are limited, with the majority being observational epidemiological studies that provide no conclusions on cause and effect or clear links on the molecular mechanisms. The few cell culture and supplementation studies that have investigated adipogenesis in human cells indicate that, in contrast to findings from rodent studies, vitamin D is proadipogenic. There is insufficient evidence to determine whether 1) vitamin D deficiency is associated with a lean or obese phenotype, 2) vitamin D deficiency is a consequence of obesity, or (3) the effects of vitamin D on fat tissue are due to interactions with calcium

A systematic review: vitamin D status and sleeve gastrectomy

Background: Bariatric patients regularly present with insufficient vitamin D status before and after surgery, which requires substantial supplementation to treat. This review aims to assess the effect of sleeve gastrectomy on vitamin D status and the effectiveness of vitamin D supplementation. Methods: This review was conducted in accordance with the Guidelines for Meta-Analyses and Systematic Reviews of Observational Studies. Results: The current guidelines recommend initial vitamin D supplementation of at least 3000 IU/day post-operatively, with no need for follow-up testing after sleeve gastrectomy. Only one study has trialled a dose in line with the recommendations for this patient group. They found that it was effective in improving VitD status. Conclusions: On-going monitoring of vitamin D status is necessary, as the recommended level is not often reached

Vitamin D: Australian dietitian's knowledge and practices

Aim: To survey dietitians on their knowledge and practices regarding vitamin D (VitD) intake, sources, supplementation and effect on disease state

Communicating Health to Young Adults Using Social Media: How, Where, and When?

Communication with young adults about healthy lifestyle behaviours needs to result in improvements in dietary choices to impact the prevalence of diet-related diseases. This paper presents the health beliefs, behaviours, and communication practices in young Australian adults (n = 2019) by their pre-defined psycho-behavioural characteristics: Lifestyle Mavens, Health-Conscious, Aspirational Healthy Eaters, Balanced-All Rounders, Contemplating Another Day, or Blissfully Unconcerned. The Lifestyle Mavens and Health-Conscious groups were more likely to actively seek out health information on social media (p < 0.05). Lifestyle Mavens were the most likely to engage with health and food content on social media, whereas the Blissfully Unconcerned were the least likely to engage (p < 0.05). Lifestyle Mavens are more likely to report creating food and health-related content for social media, whereas Aspirational Healthy Eaters are more likely to report searching for food and health-related content online, but are less likely to share or create content. Contemplating Another Day are more likely to report interactions with commercial content. This paper defines how psycho-behavioural segments communicate about health, where they look for information, how they may prefer to receive health messages, and when they are most receptive to messages. By applying existing robust market segmentation techniques, this paper provides nuanced information that challenges the assumption that online social media health information is preferred by all young adults

Nutrition Meets Social Marketing: Targeting Health Promotion Campaigns to Young Adults Using the Living and Eating for Health Segments

Young adults are a key target age group for lifestyle behaviour change as adoption of healthier behaviours has the potential to impact long term health. This paper arises from a multi-disciplinary research project, Communicating Health, which aims to bridge the gap between nutritionists, media, and social marketing professionals to produce the tools that may be used to improve engagement with young adults and reduce the prevalence of obesity. The aim of this paper is to provide nuanced details of the psycho-behavioral characteristics of each of these Living and Eating for Health Segments (LEHS). The design and validation of the LEHS employed a four-stage mixed methods design underpinned by the Integrated Model of Behaviour Change and incorporating sequential formative, qualitative, and quantitative phases. This paper defines the psycho-behavioural characteristics of six distinct market segments: Lifestyle Mavens, Aspirational Healthy Eaters, Balanced-all Rounders, the Health Conscious, those Contemplating Another Day, and the Blissfully Unconcerned. These psycho-behavioural characteristics are important to understand to help build our capability in designing campaigns that are specifically and purposefully targeting these different market segments of young adults. Social marketing practices can enhance the utility of nutrition and health messages to young adults in order to engage them in adopting positive lifestyle change. Tailoring health promotions to the perceived needs of sub-groups or segments of young adults should lead to increased engagement and uptake of messages and cost-efficient use of health promotion budgets

Association of sun exposure, skin colour and body mass index with vitamin D status in individuals who are morbidly obese

Vitamin D deficiency is a common issue, particularly in obese populations, and is tested by assessing serum 25(OH)D concentrations. This study aimed to identify factors that contribute to the vitamin D status in fifty morbidly obese individuals recruited prior to bariatric surgery. Data collected included serum 25(OH)D concentrations, dietary and supplement intake of vitamin D, sun exposure measures, skin colour via spectrophotometry, and genotype analysis of several single nucleotide polymorphisms in the vitamin D metabolism pathway. Results showed a significant correlation between serum 25(OH)D concentrations and age, and serum 25(OH)D and ITAC score (natural skin colour). Natural skin colour accounted for 13.5% of variation in serum 25(OH)D, with every 10 degrees increase in ITAC score (i.e., lighter skin) leading to a 9 nmol/L decrease in serum 25(OH)D. Multiple linear regression using age, ITAC score, and average UV index in the three months prior to testing, significantly predicted serum 25(OH)D concentrations (R-2 = 29.7%). Single nucleotide polymorphisms for all vitamin D genes tested, showed lower serum 25(OH)D for those with the rare genotype compared to the common genotype; this was most pronounced for fok1 and rs4588, where those with the rare genotype were insufficient (= 50 nmol/L). Assessing vitamin D status in individuals with morbid obesity requires testing of 25(OH)D, but potential risk factors for this population include natural skin colour and age