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Article
Publication date: 1 March 1979

Elsie M. Widdowson

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…

Abstract

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.

Details

Nutrition & Food Science, vol. 79 no. 3
Type: Research Article
ISSN: 0034-6659

Article
Publication date: 23 March 2022

Muneeb Ahmad Malik, Yasmeena Jan, Afrozul Haq, Jasmeet Kaur and Bibhu Prasad Panda

The purpose of this study was to optimize the parameters for enhancing the vitamin D2 formation in three edible mushroom varieties, namely, shiitake mushroom (Lentinula

Abstract

Purpose

The purpose of this study was to optimize the parameters for enhancing the vitamin D2 formation in three edible mushroom varieties, namely, shiitake mushroom (Lentinula edodes), white button mushroom (Agaricus bisporus) and oyster mushroom (Pleurotus ostreatus) using ultraviolet (UV) irradiation.

Design/methodology/approach

Freshly harvested mushrooms were irradiated with UV-B and UV-C lamps. Further, mushrooms were treated with UV-B at a distance ranging between 10 and 50 cm from the UV light source, for 15–150 min, to maximize the conversion of ergosterol to vitamin D2. Analysis of vitamin D2 content in mushrooms before and after UV exposure was done by high pressure liquid chromatography (HPLC).

Findings

HPLC results showed a significant (p < 0.001) increase in vitamin D2 levels of shiitake (17.3 ± 0.35 µg/g), button (24.9 ± 0.71 µg/g) and oyster (19.1 ± 0.35 µg/g) mushrooms, irradiated with UV-B at a distance of 20–30 cm for 120 min. Further, stability studies revealed that vitamin D2 levels in UV-B-irradiated mushrooms gradually increased for 48 and 72 h of storage at room and refrigeration temperatures, respectively. During cooking operations, 62%–93% of vitamin D2 was retained in UV-B-irradiated mushrooms.

Originality/value

This study describes the most effective parameters such as ideal wavelength, mushrooms size, duration of exposure and distance from UV sources for maximum vitamin D2 formation in edible mushrooms using UV irradiation. Further, assessment of vitamin D2 stability in UV exposed mushrooms during storage period and cooking operations has been carried out. In addition, this study also provides a comparison of the vitamin D2 levels of the three widely cultivated and consumed mushroom varieties treated simultaneously under similar UV exposure conditions.

Details

Nutrition & Food Science, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0034-6659

Keywords

Article
Publication date: 24 October 2021

Honglin Dong, Viktorija Asmolovaite, Nareen Marseal and Maryam Mearbon

Vitamin D deficiency is prevalent worldwide. This paper aims to investigate the vitamin D status and dietary intake in young university students.

Abstract

Purpose

Vitamin D deficiency is prevalent worldwide. This paper aims to investigate the vitamin D status and dietary intake in young university students.

Design/methodology/approach

Forty-one healthy students aged 18–29 years from Coventry University UK were recruited during January-February 2019, including white Caucasians (n = 18), African-Caribbeans (n = 14) and Asians (n = 9). Plasma 25(OH)D concentrations were measured and dietary vitamin D intake was determined. Chi-square and simple linear regression were used to analyse the data.

Findings

The plasma 25(OH)D concentrations were (36.0 ± 22.2) nmol/L in all subjects, (46.5 ± 25.3) nmol/L in white Caucasians, (22.6 ± 7.4) nmol/L in African-Caribbeans and (37.4 ± 21.7 nmol/L) in Asians. The majority (85.7%) of African-Caribbeans were vitamin D deficient compared with 22.2% of white Caucasians and 33.3% of Asians (p = 0.001). Overweight/obese subjects showed a significant higher proportion of vitamin D deficiency (65%) than normal weight subjects (28.6%) (p = 0.04). The average dietary vitamin D intake in all subjects was (4.6 ± 3.9) µg/day. Only 12.1% of the subjects met the recommended dietary vitamin D intake of 10 µg/day. Dietary vitamin D intake (p = 0.04) and ethnicity (p = 0.01) were significant predictors of 25(OH)D levels and accounted for 13% and 18.5% of 25(OH)D variance, respectively.

Research limitations/implications

This small-scale study showed an alarmingly high prevalence of vitamin D deficiency among subjects from African-Caribbean origin during wintertime. Education programs and campaigns are urgently needed to fight the vitamin D deficiency in this population.

Originality/value

The targeted population were in a critical period of transition from adolescence toward adulthood involving in changes in behaviours and nutrition.

Details

Nutrition & Food Science , vol. 52 no. 4
Type: Research Article
ISSN: 0034-6659

Keywords

Article
Publication date: 18 November 2021

Jaber Jafarzadeh, Laleh Payahoo, Mohammad Yousefi and Ali Barzegar

This paper aims to depict the mechanistic role of vitamin D on dementia prevention, relief of the severity and the complication of the disease. All papers indexed in…

Abstract

Purpose

This paper aims to depict the mechanistic role of vitamin D on dementia prevention, relief of the severity and the complication of the disease. All papers indexed in scientific databases, including Scopus, Elsevier, PubMed, Embase and Google Scholar between 2000 and 2021 were extracted and discussed. To present the mechanistic role of vitamin D in declining the severity of dementia, keywords including dementia, vitamin D, oxidative stress, inflammation, amyloid beta-Peptides were used.

Design/methodology/approach

Dementia is a prevalent cognitive disorder worldwide, especially in elderly people, which is accompanied by serious disabilities. Besides genetic, biological and lifestyle factors are involved in the incidence of dementia. An unhealthy diet along with micronutrient deficiencies are among modifiable factors. Vitamin D is one of the important micronutrients in brain health. Besides the involvement in gene expression, bone mineralization, apoptosis, inflammation, skeletal maturation, neurotropic action and hemostasis of phosphate and calcium, vitamin D also exerts neuroprotective effects via genomic and non-genomic pathways.

Findings

Vitamin D up-regulates the expression of various genes involved in dementia incidence via various mechanisms. Decreasing oxidative stress and the neuro-inflammatory cytokines levels, regulation of the expression of alternated Proteins including Tau and Amyloid-ß, calcium homeostasis in the central nervous system and also vascular are considered main mechanisms.

Originality/value

Considering the importance of diet in preventing dementia, adherence to a healthy diet that provides essential nutrients to brain function seems to be urgent. Controlling serum levels of vitamin D periodically and providing vitamin D by related sources or supplements, if there is a deficiency, is recommended. Future studies are needed to clarify other related mechanisms.

Details

Nutrition & Food Science , vol. 52 no. 4
Type: Research Article
ISSN: 0034-6659

Keywords

Abstract

Purpose

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.

Design/methodology/approach

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.

Findings

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).

Originality/value

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.

Details

Nutrition & Food Science , vol. 51 no. 5
Type: Research Article
ISSN: 0034-6659

Keywords

Article
Publication date: 17 September 2018

Leah Qubty, Basil Aboul-Enein, Lori Bechard, Joshua Bernstein and Joanna Kruk

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…

Abstract

Purpose

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.

Design/methodology/approach

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

Findings

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.

Originality/value

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.

Details

International Journal of Human Rights in Healthcare, vol. 12 no. 1
Type: Research Article
ISSN: 2056-4902

Keywords

Article
Publication date: 5 May 2020

Amir-Hossein Avestaei, Mahdi Yaghchiyan, Alireza Ali-Hemmati, Mahdieh Abbasalizad Farhangi, Mehran Mesgari-Abbasi and Parviz Shahabi

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…

Abstract

Purpose

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.

Design/methodology/approach

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.

Findings

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).

Research limitations/implications

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.

Practical implications

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.

Social implications

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.

Originality/value

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.

Details

Nutrition & Food Science, vol. 50 no. 6
Type: Research Article
ISSN: 0034-6659

Keywords

Article
Publication date: 24 July 2019

Beth Clark, Tom Hill and Carmen Hubbard

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…

Abstract

Purpose

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.

Design/methodology/approach

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.

Findings

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.

Originality/value

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.

Details

British Food Journal, vol. 121 no. 9
Type: Research Article
ISSN: 0007-070X

Keywords

Article
Publication date: 1 November 2018

Beth Clark, Julie Doyle, Owen Bull, Sophie McClean and Tom Hill

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…

Abstract

Purpose

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.

Design/methodology/approach

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.

Findings

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.

Originality/value

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

Details

Nutrition & Food Science, vol. 49 no. 3
Type: Research Article
ISSN: 0034-6659

Keywords

Article
Publication date: 18 July 2019

Faiza Syed, Malik Shah Zaman Latif, Iftikhar Ahmed, Sadia Bibi, Saif Ullah and Nauman Khalid

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

Abstract

Purpose

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

Design/methodology/approach

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.

Findings

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.

Originality/value

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.

Details

Nutrition & Food Science , vol. 50 no. 1
Type: Research Article
ISSN: 0034-6659

Keywords

1 – 10 of over 3000