Vitamin D - From Essentiality to Functionality

2012 ◽  
Vol 82 (5) ◽  
pp. 321-326 ◽  
Author(s):  
Heike Bischoff-Ferrari

Vitamin D is essential in bone and muscle health. Severe deficiency (25-hydroxyvitamin D serum levels < 25 nmol/l) can result in rickets and osteomalacia, fractures, myopathy and falls. All recent recommendations on vitamin D agree that children and adults should reach a target 25-hydroxyvitamin D range of at least 50 nmol/l (threshold for normal vitamin D status) and 50 % of the population may be below that threshold. A vitamin D intake of 600 to 800 IU per day as recommended today will prevent about 97 % of children and adults from vitamin D deficiency. Notably, a higher 25-hydroxyvitamin D threshold of more than 60 nmol/l is needed for optimal functionality, fall and fracture in adults age 65 and older.

2015 ◽  
Vol 4 ◽  
Author(s):  
Michiel G. J. Balvers ◽  
Elske M. Brouwer-Brolsma ◽  
Silvia Endenburg ◽  
Lisette C. P. G. M. de Groot ◽  
Frans J. Kok ◽  
...  

AbstractVitamin D is a fat-soluble hormone that traditionally has been linked to bone health. Recently, its involvement has been extended to other (extra-skeletal) disease areas, such as cancer, CVD, energy metabolism and autoimmune diseases. Vitamin D deficiency is a worldwide problem, and several recommendation-setting bodies have published guidelines for adequate vitamin D intake and status. However, recommendations from, for example, the Health Council of the Netherlands do not provide advice on how to treat vitamin D deficiency, a condition that is often encountered in the clinic. In addition, these recommendations provide guidelines for the maintenance of ‘minimum levels’, and do not advise on ‘optimum levels’ of vitamin D intake/status to further improve health. The NutriProfiel project, a collaboration between the Gelderse Vallei Hospital (Ede, the Netherlands) and the Division of Human Nutrition of Wageningen University (Wageningen, the Netherlands), was initiated to formulate a protocol for the treatment of vitamin deficiency and for the maintenance of optimal vitamin D status. To discuss the controversies around treatment of deficiency and optimal vitamin D status and intakes, a workshop meeting was organised with clinicians, scientists and dietitians. In addition, a literature review was conducted to collect recent information on optimal intake of vitamins, their optimal circulating concentrations, and effective dosing regimens to treat deficiency. This information has been translated into the NutriProfiel advice, which is outlined in this article.


2012 ◽  
Vol 16 (3) ◽  
pp. 544-548 ◽  
Author(s):  
Raed M Kanan ◽  
Yousef M Al Saleh ◽  
Hana M Fakhoury ◽  
Maysoon Adham ◽  
Saleh Aljaser ◽  
...  

AbstractObjectiveThe aim of the present study was to investigate vitamin D status among female out-patients in Saudi Arabia during the summer and winter seasons.DesignData were retrospectively collected using medical record abstraction.SettingA multidisciplinary hospital in Riyadh between January and December 2009.SubjectsSaudi females (age ≥19 years;n1556) attending out-patient clinics for various complaints comprised the studied population. The population was subdivided into two groups depending on the date of their visit where blood samples were collected: summer (n659) and winter groups (n897). The summer group was further subdivided into premenopausal (age 19–49 years;n425) and postmenopausal subgroups (age ≥50 years;n234). Similarly, the winter group was subdivided into premenopausal (n543) and postmenopausal subgroups (n354). Serum levels of 25-hydroxyvitamin D (25(OH)D) were measured using HPLC.ResultsThe prevalence of vitamin D deficiency (25(OH)D <50 nmol/l) was high in both premenopausal and postmenopausal groups (80 % and 68 %, respectively) during the summer, as well as during the winter (85 % and 76 %, respectively).ConclusionsA high prevalence of vitamin D deficiency among Saudi female out-patients was observed throughout the year despite the routine supplementation with 10–20 μg vitamin D3for postmenopausal women. Clinicians should seriously consider determining the vitamin D status of Saudi females routinely and prescribing them proper supplementation.


2020 ◽  
Vol 41 (3) ◽  
pp. 103-126
Author(s):  
Indra Ramasamy

Vitamin D is essential for bone health and is known to be involved in immunomodulation and cell proliferation. Vitamin D status remains a significant health issue worldwide. However, there has been no clear consensus on vitamin D deficiency and its measurement in serum, and clinical practice of vitamin D deficiency treatment remains inconsistent. The major circulating metabolite of vitamin D, 25-hydroxyvitamin D (25(OH)D), is widely used as a biomarker of vitamin D status. Other metabolic pathways are recognised as important to vitamin D function and measurement of other metabolites may become important in the future. The utility of free 25(OH)D rather than total 25(OH)D needs further assessment. Data used to estimate the vitamin D intake required to achieve a serum 25(OH)D concentration were drawn from individual studies which reported dose-response data. The studies differ in their choice of subjects, dose of vitamin D, frequency of dosing regimen and methods used for the measurement of 25(OH)D concentration. Baseline 25(OH)D, body mass index, ethnicity, type of vitamin D (D2 or D3) and genetics affect the response of serum 25(OH)D to vitamin D supplementation. The diversity of opinions that exist on this topic are reflected in the guidelines. Government and scientific societies have published their recommendations for vitamin D intake which vary from 400–1000 IU/d (10–25 µg/d) for an average adult. It was not possible to establish a range of serum 25(OH)D concentrations associated with selected non-musculoskeletal health outcomes. To recommend treatment targets, future studies need to be on infants, children, pregnant and lactating women.


2018 ◽  
Vol 40 (4) ◽  
pp. 1109-1151 ◽  
Author(s):  
Roger Bouillon ◽  
Claudio Marcocci ◽  
Geert Carmeliet ◽  
Daniel Bikle ◽  
John H White ◽  
...  

AbstractThe etiology of endemic rickets was discovered a century ago. Vitamin D is the precursor of 25-hydroxyvitamin D and other metabolites, including 1,25(OH)2D, the ligand for the vitamin D receptor (VDR). The effects of the vitamin D endocrine system on bone and its growth plate are primarily indirect and mediated by its effect on intestinal calcium transport and serum calcium and phosphate homeostasis. Rickets and osteomalacia can be prevented by daily supplements of 400 IU of vitamin D. Vitamin D deficiency (serum 25-hydroxyvitamin D <50 nmol/L) accelerates bone turnover, bone loss, and osteoporotic fractures. These risks can be reduced by 800 IU of vitamin D together with an appropriate calcium intake, given to institutionalized or vitamin D–deficient elderly subjects. VDR and vitamin D metabolic enzymes are widely expressed. Numerous genetic, molecular, cellular, and animal studies strongly suggest that vitamin D signaling has many extraskeletal effects. These include regulation of cell proliferation, immune and muscle function, skin differentiation, and reproduction, as well as vascular and metabolic properties. From observational studies in human subjects, poor vitamin D status is associated with nearly all diseases predicted by these extraskeletal actions. Results of randomized controlled trials and Mendelian randomization studies are supportive of vitamin D supplementation in reducing the incidence of some diseases, but, globally, conclusions are mixed. These findings point to a need for continued ongoing and future basic and clinical studies to better define whether vitamin D status can be optimized to improve many aspects of human health. Vitamin D deficiency enhances the risk of osteoporotic fractures and is associated with many diseases. We review what is established and what is plausible regarding the health effects of vitamin D.


2014 ◽  
Vol 18 (2) ◽  
pp. 208-217 ◽  
Author(s):  
Adda Bjarnadottir ◽  
Asa Gudrun Kristjansdottir ◽  
Hannes Hrafnkelsson ◽  
Erlingur Johannsson ◽  
Kristjan Thor Magnusson ◽  
...  

AbstractObjectiveThe aim was to investigate autumn vitamin D intake and status in 7-year-old Icelanders, fitting BMI and cardiorespiratory fitness as predictors.DesignThree-day food records and fasting blood samples were collected evenly from September to November, and cardiorespiratory fitness was measured with an ergometer bike. Food and nutrient intakes were calculated, and serum 25-hydroxyvitamin D (s-25(OH)D) and serum parathyroid hormone were analysed. Suboptimal vitamin D status was defined s-25(OH)D <50 nmol/l, and deficient status as s-25(OH)D <25 nmol/l.SettingSchool-based study in Reykjavik, Iceland in 2006.SubjectsOf the 7-year-olds studied (n 265), 165 returned valid intake information (62 %), 158 gave blood samples (60 %) and 120 gave both (45 %).ResultsRecommended vitamin D intake (10 μg/d) was reached by 22·4 % of the children and 65·2 % had s-25(OH)D <50 nmol/l. Median s-25(OH)D was higher for children taking vitamin D supplements (49·2 nmol/l v. 43·2 nmol/l, respectively; P < 0·0 0 1). Median s-25(OH)D was lower in November (36·7 nmol/l) than in September (59·9 nmol/l; P < 0·001). The regression model showed that week of autumn accounted for 18·9 % of the variance in s-25(OH)D (P < 0·001), vitamin D intake 5·2 % (P < 0·004) and cardiorespiratory fitness 4·6 % (P < 0·005).ConclusionsA minority of children followed the vitamin D recommendations and 65 % had suboptimal vitamin D status during the autumn. Week of autumn was more strongly associated with vitamin D status than diet or cardiorespiratory fitness, which associated with vitamin D status to a similar extent. These results demonstrate the importance of sunlight exposure during summer to prevent suboptimal vitamin D status in young schoolchildren during autumn in northern countries. An increased effort is needed for enabling adherence to the vitamin D recommendations and increasing outdoor activities for sunlight exposure.


2019 ◽  
Vol 23 (7) ◽  
pp. 1179-1183 ◽  
Author(s):  
Madhava Vijayakumar ◽  
Vijayalakshmi Bhatia ◽  
Biju George

AbstractObjectiveTo study plasma 25-hydroxyvitamin D (25(OH)D) status of children in Kerala, southern India, and its relationship with sociodemographic variables.DesignCross-sectional observational study.SettingTertiary government hospital.ParticipantsChildren (n 296) with trivial acute illness were enrolled. Sun exposure and Ca and vitamin D intakes (7 d dietary recall) were documented. Serum Ca, P, alkaline phosphatase, plasma 25(OH)D and parathyroid hormone (PTH) were measured.ResultsPrevalence of vitamin D deficiency (plasma 25(OH)D <30 nmol/l) was 11·1% (median, interquartile range (IQR): 52·6, 38·4–65·6 nmol/l). Children who ate fish daily had significantly higher plasma 25(OH)D than those who did not (median, IQR: 52·5, 40·8–68·9 v. 49·1, 36·2–60·7 nmol/l; P = 0·02). Those investigated in the months of March–May showed highest 25(OH)D v. those enrolled during other times (median, IQR: 58·7, 45·6–81·4 v. 45·5, 35·6–57·4 nmol/l; P <0·001). Plasma 25(OH)D correlated positively with serum P (r = 0·24, P <0·001) and Ca intake (r = 0·16, P 0·03), negatively with age (r = −0·13, P 0·03) and PTH (r = −0·22, P <0·001.). On linear regression, summer season (March–May), lower age, daily fish intake and higher Ca intake were independently associated with plasma 25(OH)D.ConclusionsPrevalence of vitamin D deficiency is low in Kerala. The natural fish diet of coastal Kerala and the latitude may be protective. Public health policy in India should take account of this geographical diversity.


2017 ◽  
Vol 118 (7) ◽  
pp. 550-558 ◽  
Author(s):  
Yannis Manios ◽  
George Moschonis ◽  
Toine Hulshof ◽  
Anne-Sophie Bourhis ◽  
George L. J. Hull ◽  
...  

AbstractThe current study was aiming to report the prevalence of suboptimal vitamin D status among schoolchildren in Greece and investigate the role of sex, urbanisation and seasonality on vitamin D status. A sample of 2386 schoolchildren (9–13 years old) from four distinct prefectures was examined. The prevalence of 25-hydroxyvitamin D (25(OH)D) concentration <30 and <50 nmol/l (vitamin D deficiency and insufficiency respectively) was 5·2 and 52·5 %, respectively. Girls had a higher prevalence of 25(OH)D<30 (7·2 v. 3·2 %) and 50 nmol/l (57·0 v. 48·0 %) than boys (P<0·001). The highest prevalence rates of 25(OH)D<30 and 50 nmol/l (9·1 and 73·1 %, respectively) were observed during spring (April to June), whereas the lowest (1·5 and 31·9 %, respectively) during autumn (October to December). The prevalence of 25(OH)D<50 nmol/l was higher in urban/semi-urban than rural regions, particularly during spring months (74·6 v. 47·2 %; P<0·001). Female sex, urban/semi-urban region of residence and spring months were found to increase the likelihood of vitamin D deficiency and insufficiency, with the highest OR observed for spring months (7·47; 95 % CI 3·23, 17·3 and 5·14; 95 % CI 3·84, 6·89 for 25(OH)D<30 and 50 nmol/l respectively). In conclusion, despite the southerly latitude, the prevalence of low vitamin D status among primary schoolchildren in Greece is comparable to or exceeds the prevalence reported among children and adolescents on a European level. Sub-populations at highest risk are girls in urban/semi-urban areas during spring months, thus indicating the need for effective initiatives to support adequate vitamin D status in these population groups.


Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 499
Author(s):  
Bruce N. Ames ◽  
William B. Grant ◽  
Walter C. Willett

African Americans have higher incidence of, and mortality from, many health-related problems than European Americans. They also have a 15 to 20-fold higher prevalence of severe vitamin D deficiency. Here we summarize evidence that: (i) this health disparity is partly due to insufficient vitamin D production, caused by melanin in the skin blocking the UVB solar radiation necessary for its synthesis; (ii) the vitamin D insufficiency is exacerbated at high latitudes because of the combination of dark skin color with lower UVB radiation levels; and (iii) the health of individuals with dark skin can be markedly improved by correcting deficiency and achieving an optimal vitamin D status, as could be obtained by supplementation and/or fortification. Moderate-to-strong evidence exists that high 25-hydroxyvitamin D levels and/or vitamin D supplementation reduces risk for many adverse health outcomes including all-cause mortality rate, adverse pregnancy and birth outcomes, cancer, diabetes mellitus, Alzheimer’s disease and dementia, multiple sclerosis, acute respiratory tract infections, COVID-19, asthma exacerbations, rickets, and osteomalacia. We suggest that people with low vitamin D status, which would include most people with dark skin living at high latitudes, along with their health care provider, consider taking vitamin D3 supplements to raise serum 25-hydroxyvitamin D levels to 30 ng/mL (75 nmol/L) or possibly higher.


2020 ◽  
Vol 9 (3) ◽  
pp. 123-130
Author(s):  
Burcu Kayılı ◽  
Muhammet Ali Oruç ◽  
Yasemin Alan ◽  
Murat Alan ◽  
Deniz Can Öztekin

Aim: The aim of this study was to compare vitamin D levels between pregnant women with hyperemesis gravidarum before 12 weeks of gestation and healthy pregnant women at similar ages. Methods: Sixty pregnancies with hyperemesis gravidarum and 60 age compatible healthy pregnancies applied to our facility were included in the study. Demographic characteristics, maternal thyroid function tests and 25-Hydroxyvitamin D levels were evaluated. Student t test was used for the variables with normal distribution and Mann-Whitney U test was used to analyze the variables without normal distribution. Results: Only one pregnant woman had normal vitamin D levels (>30ng/ml), whereas 71 patients had deficiency (10-30 ng/ml), and 48 had severe deficiency (<10 ng/ml). The mean vitamin D level of the total 120 pregnancies was 11.9±5.00 ng/ml (9.92±3.67 ng/ml in case group, 13.88±5.38 ng/ml in control group). The mean value of vitamin D was found to be significantly lower in hyperemesis gravidarum. 45% (n=27) of the pregnant women had vitamin D deficiency, whereas 55% (n=33) of them had severe deficiency. Free T3 and T4 levels were significantly higher than the control group, and thyroid-stimulating hormone level was significantly lower. Conclusion: Vitamin D levels of pregnant women with hyperemesis gravidarum were significantly lower. Vitamin D deficiency should be considered in patients with hyperemesis gravidarum. Keywords: pregnancy, hyperemesis gravidarum, Vitamin D deficiency


2011 ◽  
Vol 38 (9) ◽  
pp. 2000-2004 ◽  
Author(s):  
CHRISTINA F. PELAJO ◽  
JORGE M. LOPEZ-BENITEZ ◽  
LAURIE C. MILLER

Objective.To evaluate the prevalence of vitamin D deficiency, as well as factors associated with serum 25-hydroxyvitamin D [25(OH)D] levels, in children attending a pediatric rheumatology clinic, and to determine whether there was a difference in serum 25(OH)D levels and in vitamin D deficiency between children with autoimmune disorders and nonautoimmune conditions.Methods.Cross-sectional analysis of serum 25(OH)D levels of patients between the ages of 2 and 19 years, seen between November 2008 and October 2009.Results.A total of 254 patients were studied (169 autoimmune disorders, 85 nonautoimmune conditions). The mean age of study patients was 12.3 years; 67% were female and 80% were white. In the autoimmune disorders group, 23% had vitamin D deficiency [serum 25(OH)D < 20 ng/ml], and in the nonautoimmune conditions group 14% were vitamin D deficient. The average level of serum 25(OH)D was 28.6 (± 11) ng/ml (range 2 to 59). Age, ethnicity, body mass index, use of supplements, and season were significantly associated with serum levels of 25(OH)D (all p ≤ 0.02). The OR of patients with autoimmune disorders being vitamin D deficient was 2.3, in relation to patients with nonautoimmune conditions (p = 0.04).Conclusion.Twenty percent of patients attending a pediatric rheumatology clinic were vitamin D deficient. Patients with autoimmune disorders were more likely to be vitamin D deficient than patients with nonautoimmune conditions. Screening of serum 25(OH)D levels should be performed for patients with autoimmune disorders.


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