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Vitamin D is one of the fat‐soluble vitamins. Its function in the body is to promote the absorption of calcium from the intestine and deposition of calcium in developing bone. If the young child does not have sufficient vitamin D he develops rickets. Vitamin D can be obtained in two ways, from the food, or by the action of the ultraviolet rays of the sunlight on a fatty substance, 7 dehydrocholesterol, in the deeper layers of the skin. There is at present no method for making a quantitative assessment of the amount of vitamin D obtained in this way, but it is believed to be the natural and most important means by which the body acquires its vitamin D. However, if a person does not expose his body to the sunlight, either because he (or more likely she) covers it up when she goes out, or stays indoors, or lives in northern parts of the world where there is no sunlight for many months of the year, there can be no conversion of 7 dehydrocholesterol to vitamin D. Even as far south as Scotland in the winter there is virtually no ultraviolet light. Vitamin D can be stored in the liver and body fat, so that a sunny summer may allow a store to be built up which can be drawn upon in the winter. However, whenever sunlight and particularly ultraviolet light does not reach exposed parts of the skin dietary sources of vitamin D become of major importance. The richest dietary sources of vitamin D are fatty fish such as herrings, kippers, pilchards and mackerel, but few people eat enough of these fish for them to be an important day to day provider of the vitamin. Most of our dietary vitamin D comes from margarine which is fortified with the vitamin, and eggs. Egg yolk contains about 5 micrograms of vitamin D per 100 grams, fortified margarine 8 micrograms and herrings, bloaters and kippers 25 micrograms per 100 grams.

Adipose tissue accumulation by trapping vitamin D and reducing its level may cause serious side effects. The purpose of this study is to determine the effects of vitamin D supplementation on dehydroepiandrosterone (DHEA), paraoxonase 1 (PON 1), insulin, free fatty acid (FFA), apolipoprotein-AI (Apo-AI) and apolipoprotein B (Apo-B) concentration in obese and overweight participants under low-calorie diet (LCD) program.

Healthy overweight and obese individuals (n = 70) with vitamin D deficiency were randomly assigned into 2 groups to receive either vitamin D supplements (an oral 2,000 IU vitamin D supplement) or placebo for 8 weeks.

All the participants were given an LCD program during the intervention. Vitamin D supplementation led to a significant increase in the levels of 25(OH)D (vitamin D vs placebo groups: 36.6 ± 9.8 vs 19.9 ± 3.5 ng/mL, p < 0.001), PON 1 levels (vitamin D vs placebo groups: 80 ± 25 vs 58 ± 23.2 ng/mL, p = 0.001), DHEA concentration (vitamin D vs placebo groups: 2.3 ± 0.7 vs 1.5 ± 0.6 ng/mL, p < 0.001) and Apo-AI levels (vitamin D vs placebo groups 3.7 ± 0.5 vs 3 ± 0.5 mg/dL, p < 0.001). Besides, intake of vitamin D supplements led to a significant decrease in FFA (vitamin D vs placebo groups: 3.1 ± 0.75 vs 3.5 ± 0.5 ng/mL, p = 0.001). After adjusting the analyses based on baseline levels, age and baseline body mass index measures, significant changes were observed in the insulin levels (0.03 ± 0.06 vs −1.7 ± 0.6 µIU/ml, p = 0.04). But the authors did not find any significant difference in the concentration of Apo-B between groups (vitamin D vs placebo groups: 71.5 ± 35.5 vs 66.6 ± 28.5 mg/dL, p = 0.05).

Overall vitamin D supplementation for eight weeks among vitamin D-deficient obese and overweight participants had beneficial effects on serum DHEA PON 1 FFA insulin and Apo- AI while it did not affect the Apo-B concentration.

Obesity is a major risk factor for chronic renal fibrosis and kidneys’ structural and inflammatory impairments. This study aims to examine the possible therapeutic effects of vitamin D supplementation against renal inflammatory and kidney’s structural fibrosis and degeneration.

Forty male Wistar rats were divided into two groups for 16 weeks: normal diet (ND) and high-fat diet (HFD); then, each group was subdivided into two groups including ND, ND + vitamin D and HFD, HFD + vitamin D. Vitamin D supplementation was done for five weeks at 500 IU/kg dosage. Renal tissue concentrations of tumor necrosis factor (TNF)-α, interleukin 6, interleukin 1 beta, monocyte chemoattractant protein (MCP)-1 and transforming growth factor-beta (TGF-β), serum values of lipids, markers of glucose homeostasis and urea, creatinine and uric acid and renal tissue histological and structural changes were determined.

HFD feeding caused remarkable histological and structural changes including higher TNF-α, MCP-1 and TGF-β concentrations in renal tissues of rats, whereas vitamin D has potent anti-inflammatory effects (P = 0.036, 0.047 and 0.02, respectively). Vitamin D administration also reduced urea and uric acid concentrations (P = 0.023 and 0.049, respectively). Moreover, vitamin D reduced glomerulomegaly, reduced lipid accumulation and limited dilated Bowman’s space in rats and improved glycemic status by increasing insulin (P = 0.04) and reducing insulin resistance (P = 0.006).

The current study has some limitations. It was better to measure the level of inflammatory cytokines’ expression in the kidney tissues. Additionally, the measurement of baseline values of inflammatory cytokines was not possible because of the possibility of animals’ drop-out.

According to the study findings, vitamin D treatment in the current report showed a significant therapeutic role in reducing inflammation, improving glycemic and lipid abnormalities and structural and histological modifications in renal tissues of rats. These findings have a great value because after confirming in a human model, vitamin D can be suggested as a potential therapeutic tool in clinical practice.

After being confirmed by other animal or human researches, the results of the current work could have great social implications by reducing the prevalence of obesity-related renal complications and highlighting the beneficial roles of vitamin D.

To the best of the authors’ knowledge, this is the first study to investigate the histological and inflammatory changes in the kidneys and metabolic parameters in the HFD induced rats and also clarified the therapeutic roles of vitamin D in ameliorating the inflammatory, histological, metabolic and functional changes in the kidneys of obese rats.

As natural dietary sources of vitamin D are not consumed in sufficient quantities, fortified foods could play a role in maintaining vitamin D sufficiency. With public consultation, an integral part of designing acceptable fortification strategies, the purpose of this paper is to understand public awareness and perception of vitamin D fortified foods.

A mixed-methods approach was taken with two focus groups and 109 surveys conducted using a non-probability sample from North-East England. Thematic analysis of focus group data identified six themes, with factor and cluster analysis identifying seven factors and four clusters, respectively, which highlighted differences in vitamin D knowledge and fortified food perceptions.

Despite identifying sunlight as the main vitamin D source (91 per cent), participants were less aware of the main dietary source (33 per cent), and few could state fortified products (51 per cent). Although attitudes towards fortification were generally favourable (63 per cent agreeing that selected products should be fortified), nearly half (43 per cent) were unsure if more products should be made available. Results suggest that more natural products to complement existing market offerings would be most preferred. Factor and cluster analysis results identified awareness of health benefits and/or dietary sources as essential to have favourable attitudes towards fortified products.

This research adds to the limited literature regarding consumer attitudes towards fortified foods. It highlights a need to improve public awareness and labelling of fortified products to potentially increase fortified food consumption.

Vitamin D deficiency is a well-recognised public health problem within the UK, with specific population groups more vulnerable to deficiency. Two pilot studies were used to explore awareness of vitamin D deficiency and attitudes towards food fortification.

A survey of 120 participants from five at-risk groups (South Asians, Blacks, Middle Eastern, Far Eastern and Caucasian older adults over 65 years) plus a group of British Caucasians who do not avoid sun exposure explored awareness of vitamin D, sun exposure knowledge and behaviour and attitudes towards food fortification. The latter group was included to provide a comparison group who were at a reduced risk of deficiency. χ² was used to test associations between categorical variables and the study groups. The second study used three focus groups and two interviews, conducted on young South Asian females and examined knowledge and awareness of vitamin D and vitamin D-fortified foods.

A lack of knowledge and misconceptions were highlighted by both studies in relation to at-risk factors, including sunlight exposure (p = 0.037), dietary intakes (p = 0.0174) and darker skin pigmentation (p = 0.023), sources of vitamin D and the health benefits associated with optimal consumption. Attitudes to mandatory fortification of some foods varied significantly (p = 0.004) between the groups with acceptance rates for Blacks (68 per cent), those over 65 years (50 per cent), Middle Eastern (67 per cent) and Far Eastern (73 per cent), whereas the control (71 per cent) showed no acceptance, and South Asians gave a mixed response (48 per cent No). Focus group findings highlighted positive views towards fortification, although this was less for mandatory as opposed to voluntary fortification. Both pilot studies highlight the need for more research into this area, to create more effective public health policies.

The research presents novel insights into a topical area where there is limited research.

The purpose of this paper is to access the present situation of the Pakistani population that suffers from vitamin D deficiency.

A review-based study was conducted based on publications from Pakistan between the years 2008 and 2018. The publications were archived from Pub Med and Google Scholar databases. A total of 18 publications were shortlisted, based on the cutoff values of vitamin D sufficiency, insufficiency and deficiency.

As per the data, 38.5 per cent of the participants were males, 48.7 per cent were females and 12.8 per cent of the studies have not mentioned the genders of the participants. The cumulative results show that 58.17 per cent (95 per cent CI: 52.17, 64.16) of the population is vitamin D-deficient and 26.65 per cent (95 per cent CI: 21.63, 31.66) is insufficient in vitamin D. The highest level of vitamin D deficiency was reported from Sindh (62.15 per cent), followed by Khyber Pakhtunkhwa (60.57 per cent), Punjab (51.75 per cent) and the Federal Capital (49.25 per cent). Moreover, Cochran’s Q test indicated considerable heterogeneity (p = >0.001) with regard to Vitamin D deficiency (VDD) prevalence found among samples from the selected studies.

The present analysis suggests that more than half of the Pakistani population suffers from VDD, which, thus, should be considered as an epidemic and treated likewise.

Somalia is an East African nation with a history of civil unrest that produced a significant influx of refugees in the USA in the last 25 years. Between 2000 and 2010, 40 percent of all US Somali refugees settled in Minnesota, which produces new cultural and health challenges for local communities and the state government. One such challenge is vitamin D deficiency, or hypovitaminosis D (Hv-D). Hv-D is developed through insufficient exposure to sunlight and low nutrient intake leading to increased risk for weakness and inflammation, oral health problems, diabetes, cardiovascular and autoimmune diseases and malignancies. The paper aims to discuss these issues.

In this narrative review, demographic, geographic and cultural information about Somali immigration are discussed.

Recent data suggest Somalis living in northern climates (Minnesota, the USA, Helsinki, Finland, Sweden and the UK) experience significant deficiencies in vitamin D. Vitamin D is stimulated by ultraviolet light exposure, a balanced and healthy diet, and dietary supplementation. High unemployment rates affecting access to health information and clinical services, significant cultural differences and climate differences pre-dispose this population to Hv-D. Health education and health promotion programming at the community and state levels in Minnesota should recognize the risk factors associated with Hv-D and the vulnerability of Somali refugees.

Current and future health programming should be re-assessed for adequate attention to vitamin D deficiency and cultural competency associated with the Somali immigrant population.

This paper aims to review the metabolism, epidemiology and treatment of vitamin D and calcium insufficiency as well as its relation to rickets and diabetes type 1 during childhood and adolescence.

The most up‐to‐date and pertinent studies within the literature are included in this narrative review.

Vitamin D deficiency is common in developing countries and exists in both childhood and adult life. The great importance of vitamin D is the moderation of calcium (Ca) and phosphorus (P) homeostasis as well as the absorption of Ca. While insufficiency of vitamin D is a significant contributing factor to the risk of rickets in childhood, it is possible that a more marginal deficiency of vitamin D during life span contributes to osteoporosis as well as potentially to the development of various other chronic diseases such as diabetes type 1.

This paper gives a concise, up‐to‐date overview to nutritionists and dietitians on how vitamin D deficiency may effect rickets and type 1 diabetes.

Purpose of this study is to measure the Vitamin D status of healthy adults and to correlate with their lifestyle and feeding habits. Plasma 25-Hydroxyvitamin D (25(OH)D) is the most common marker of vitamin D status of an individual. Deficiency of vitamin D is defined as the serum level less than 20 ng/mL and insufficiency as 30 ng/mL which can be prevented.

Vitamin D status of healthy adults (n = 82), both male and females between the age of 18 – 50 years who were attending to the National Transport Authority, Kandy, Sri Lanka from February to March 2016, was measured and correlated with their lifestyle, feeding habits, etc.

The mean total serum D (25(OH)D in this study was 40.15 ± 3.74 nmol/l with the mean value of 42.8 ± 28.8 and 37.5 ± 16.6 for women and men, respectively. The serum calcium levels of both female and male were around 8 mg/dl and the serum total protein was 6.5 and 7 g/dl in women and men, respectively. The serum Vitamin D, calcium and total protein were not statistically significantly different between the sexes. In this study, 84 per cent of the total subjects were normocalcemic, and there was no significant relationship between vitamin D levels and their calcium levels.

This study demonstrates that there was no statistically significant correlation between the serum vitamin D with age, serum calcium or total proteins. The majority of participants who had exposure to the sunlight more than 30 mins/day had sufficient level of vitamin D and less than 30 min/day exposure had deficiency of vitamin D. Daily intake of multivitamin influenced vitamin D status of the study group.

These findings will implicate the importance of cultural, feed and social habits for the nutritional status of an individual.and there are no reported studies on vitamin D status with reference to the variation of life style.

It is very important to investigate the factors affecting to the vitamin D status of a population as such, vitamin D insufficiency or deficiency can be prevented. In Sri Lanka, the population is consisting with many ethnic groups, different ethnic groups may find some nutritional problems according to their main cultural habits.

The objectives of this study are to evaluate the Vitamin D status in a group of healthy adults between 20 and 50 years in both men and women and to find out the correlation of their vitamin D status with their lifestyle and feeding habits, etc.

This paper aims to observe the possible relationship between skin color, sun exposure level, UV protection and food intake and serum levels of 25(OH) D in Japanese older adults.

Elderly (n = 131; 65-93 years old), followed by the Tokyo Metropolitan Institute of Gerontology in the Kusatsu (36°N) received a self-applicable questionnaire about the quantity and quality of the daily sun exposure and behavior to avoid the sun. A color analyzer measured each red (R), green (G) and blue (B) component of skin color, and dietary vitamin D was estimated by food frequency questionnaire. Serum 25(OH) D levels were collected and categorized as sufficiency (>30 ng/mL), insufficiency (between 20 and 30 ng/mL) and deficiency (<20 ng/mL).

High proportion of participants had insufficiency (53 per cent) and deficiency (25 per cent) levels of 25(OH) D. Insufficiency levels were more prevalent in women (57 per cent, p = 0.048) and in participants that use gloves (49 per cent, p = 0.054) and sunscreen on face (76 per cent, p = 0.003) as a sun protection way. Participants with sufficiency levels of 25(OH) D presented lower values of R (p = 0.067), G (p = 0. 007) and B (p = 0.001) of skin color (what is meaning darker skin) and a higher fish intake (12 times per week).

The study is a cross-sectional design and brings a potential for measurement error in the recorded subjective variables. There is a memory bias in self-reported sun exposure and food consumption; however, in the multivariate analysis, it was demonstrated a significant association. Second, although the authors have sought to evaluate a number of variables that could affect the skin’s ability to synthesize vitamin D, there are many other factors that may affect this ability that could not be accounted for. Another limitation was the assessment of self-reported ultraviolet exposure data rather than direct measurement of exposure.

It was also concluded that darker skin color (a surrogate of longer-term sun exposure) participants had a lower prevalence of vitamin D insufficiency in this ethnic homogeneous population. When accessing patients’ skin color, the clinician must account for his or her ethnicity.

Governments should regulate supplementation or food fortification with vitamin D, with special focus in countries with geographical location of insufficient solar radiation for skin synthesis of this vitamin. With this, it becomes a priority that a safe sun exposure ensures the sufficient serum levels of 25 (OH) D without the use of supplements.

This report was the first to analyze skin color components associated to vitamin D levels, finding that blue and green colors were significant. The clinical implication of this find is yet to understand. It was also concluded that darker skin color (a surrogate of longer-term sun exposure) participants had a lower prevalence of vitamin D insufficiency in this ethnic homogeneous population. When accessing patients’ skin color, the clinician must account for his or her ethnicity.