Baseline Levels of Vitamin D in a Healthy Population from a Region with High Solar Irradiation

The use of vitamin D (VitD) supplements has become widespread in the last decade due not only to the dissociation between the blood levels recommended as “optimal” and those shown by the healthy population but also to its presumed beneficial effects on multiple disorders. This work evaluated the levels of 25-hydroxyvitamin D (25(OH)D) in a healthy population of European origin living in a region with high solar irradiation. In serum samples from a population-based study conducted in the Canary Islands, levels of 25(OH)D were analyzed. In 876 individuals who had no history of kidney or malabsorption disorders and, who had not been treated with calcium and/or VitD supplementation, the median 25(OH)D level was 26.3 (5th; 95th percentile, 14.3; 45.8) ng/mL. Notably, 65.4% of the population had 25(OH)D blood levels below 30 ng/mL, 23.4% below 20 ng/mL and 6.4% below 15 ng/mL. Based on the lack of evidence supporting causality between 25(OH)D levels below what is recommended as optimal (≥20 ng/mL, or even ≥30 ng/mL) and major skeletal and non-skeletal diseases, and in light of the distribution of the concentration of this vitamin in healthy adults living under optimal conditions of solar irradiation, it seems reasonable to consider 25(OH)D levels below 20 ng/mL and close to 15 ng/mL as adequate for the general population.

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COVID-19 Disease Severity and Death in Relation to Vitamin D Status among SARS-CoV-2-Positive UAE Residents

Nutrients ◽

10.3390/nu13051714 ◽

2021 ◽

Vol 13 (5) ◽

pp. 1714

Author(s):

Habiba AlSafar ◽

William B. Grant ◽

Rafiq Hijazi ◽

Maimunah Uddin ◽

Nawal Alkaabi ◽

...

Keyword(s):

Vitamin D ◽

United Arab Emirates ◽

Blood Levels ◽

Vitamin D Status ◽

Hospital Visit ◽

Serum Samples ◽

Hydroxyvitamin D ◽

Increased Risk ◽

Multiethnic Population ◽

25 Hydroxyvitamin D

Insufficient blood levels of the neurohormone vitamin D are associated with increased risk of COVID-19 severity and mortality. Despite the global rollout of vaccinations and promising preliminary results, the focus remains on additional preventive measures to manage COVID-19. Results conflict on vitamin D’s plausible role in preventing and treating COVID-19. We examined the relation between vitamin D status and COVID-19 severity and mortality among the multiethnic population of the United Arab Emirates. Our observational study used data for 522 participants who tested positive for SARS-CoV-2 at one of the main hospitals in Abu Dhabi and Dubai. Only 464 of those patients were included for data analysis. Demographic and clinical data were retrospectively analyzed. Serum samples immediately drawn at the first hospital visit were used to measure serum 25-hydroxyvitamin D [25(OH)D] concentrations through automated electrochemiluminescence. Levels < 12 ng/mL were significantly associated with higher risk of severe COVID-19 infection and of death. Age was the only other independent risk factor, whereas comorbidities and smoking did not contribute to the outcomes upon adjustment. Sex of patients was not an important predictor for severity or death. Our study is the first conducted in the UAE to measure 25(OH)D levels in SARS-CoV-2-positive patients and confirm the association of levels < 12 ng/mL with COVID-19 severity and mortality.

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Plasma 25-Hydroxyvitamin D Levels and Fracture Risk in a Community-Based Cohort of Elderly Men in Sweden

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jc.2009-2699 ◽

2010 ◽

Vol 95 (6) ◽

pp. 2637-2645 ◽

Cited By ~ 63

Author(s):

Håkan Melhus ◽

Greta Snellman ◽

Rolf Gedeborg ◽

Liisa Byberg ◽

Lars Berglund ◽

...

Keyword(s):

Vitamin D ◽

Uv Light ◽

Winter Season ◽

Community Dwelling ◽

Reference Level ◽

Blood Levels ◽

Elderly Men ◽

Hydroxyvitamin D ◽

Increased Risk ◽

25 Hydroxyvitamin D

Abstract Context: Blood levels of 25-hydroxyvitamin D [25(OH)D] is the generally accepted indicator of vitamin D status, but no universal reference level has been reached. Objective: The objective of the study was to determine the threshold at which low plasma 25(OH)D levels are associated with fractures in elderly men and clarify the importance of low levels on total fracture burden. Design and Participants: In the Uppsala Longitudinal Study of Adult Men, a population-based cohort (mean age, 71 yr, n = 1194), we examined the relationship between 25(OH)D and risk for fracture. Plasma 25(OH)D levels were measured with high-pressure liquid chromatography-mass spectrometry. Setting: The study was conducted in the municipality of Uppsala in Sweden, a country with a high fracture incidence. Main Outcome Measure: Time to fracture was measured. Results: During follow-up (median 11 yr), 309 of the participants (26%) sustained a fracture. 25(OH)D levels below 40 nmol/liter, which corresponded to the fifth percentile of 25(OH)D, were associated with a modestly increased risk for fracture, multivariable-adjusted hazard ratio 1.65 (95% confidence interval 1.09–2.49). No risk difference was detected above this level. Approximately 3% of the fractures were attributable to low 25(OH)D levels in this population. Conclusions: Vitamin D insufficiency is not a major cause of fractures in community-dwelling elderly men in Sweden. Despite the fact that cutaneous synthesis of previtamin D during the winter season is undetectable at this northern latitude of 60°, only one in 20 had 25(OH)D levels below 40 nmol/liter, the threshold at which the risk for fracture started to increase. Genetic adaptations to limited UV light may be an explanation for our findings.

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Relationship Between Level of Serum 25-Hydroxyvitamin D and Risk of Squamous Cell Carcinoma in an Iranian Population

Dermatology Practical & Conceptual ◽

10.5826/dpc.0904a06 ◽

2019 ◽

pp. 278-282

Author(s):

Mahboobeh-Sadat Hosseini ◽

Fereshteh Salarvand ◽

Amir Houshang Ehsani ◽

Pedram Noormohammadpour ◽

Shadi Azizzadeh ◽

...

Keyword(s):

Vitamin D ◽

Squamous Cell Carcinoma ◽

Cell Carcinoma ◽

Squamous Cell ◽

Outdoor Environment ◽

Hydroxyvitamin D ◽

Vitamin D Levels ◽

History Of ◽

25 Hydroxyvitamin D ◽

The Relationship

Background: The relationship between vitamin D and skin squamous cell carcinoma (SCC) is not well defined. Objective: To investigate the relationship between vitamin D levels and the incidence of skin SCC for the first time in Iran. Methods and Study Design: In this case-control study, 126 subjects were enrolled (63 in each group) out of referents to Razi Skin Hospital in Tehran in 2014. The risk factors for cancer gathered by self-reported questionnaires and blood samples were obtained to measure the level of 25-hydroxyvitamin D. Multivariate logistic regression was used to neutralize the effect of confounding factors. Results: Cases of SCC were more likely to be in men, older than 49 years and working in an outdoor environment, and with longtime exposure to sunlight and a personal history of skin cancers. Family history of skin cancer and of cigarette smoking were not significantly related to SCC. In the SCC and control groups, 69.8% and 31.7%, respectively, had sufficient levels of vitamin D (P < 0.001). Mean level of 25-hydroxyvitamin D was 40.99 ng/mL in the SCC group and 26.34 ng/mL in the control group (P < 0.05). In the unadjusted model, the level of vitamin D as a continuous variable was positively related to SCC risk. In the adjusted model, vitamin D did not independently predict the likelihood of SCC. Conclusion: Vitamin D level and SCC risk are directly related, although not in an independent fashion. Indeed, this relation is severely confounded by exposure to sunlight, which was evidenced by an increased vitamin D level in the people working outside and the higher prevalence of SCC in the same population.

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High frequency of deficient consumption and low blood levels of 25-hydroxyvitamin D in HIV-1-infected adults from São Paulo city, Brazil

Scientific Reports ◽

10.1038/srep12990 ◽

2015 ◽

Vol 5 (1) ◽

Cited By ~ 5

Author(s):

Stephanie Hael Sales ◽

Sandra Maria Matta ◽

Daniela Cardeal da Silva ◽

Tatiane Assone ◽

Luiz Augusto M. Fonseca ◽

...

Keyword(s):

Vitamin D ◽

Sao Paulo ◽

Antiretroviral Drugs ◽

Blood Levels ◽

São Paulo ◽

Hydroxyvitamin D ◽

Increased Risk ◽

Vitamin D Levels ◽

25 Hydroxyvitamin D ◽

Hiv 1

Abstract Micronutrient deficiency is common in patients with HIV/AIDS, usually caused by mal-absorption and/or drug interactions. 25-hydroxyvitamin D is of fundamental importance for the homeostasis of musculoskeletal health. The current study aimed to evaluate the nutritional status of HIV-infected subjects in order to make their nutritional diagnoses, including their vitamin D blood levels and to estimate their consumption of vitamin D. The study included 98 HIV-1-infected subjects, followed at University of São Paulo Medical School - HC-FMUSP. We performed a nutritional evaluation, along with the determination of patients’ serum 25-hydroxyvitamin D and calcium concentration, biochemical analyses and an anthropometric assessment. In the medical interview a 24-hour food recall was used (R24) to estimate daily calorie intake, macronutrients, calcium and vitamin D. A high level of vitamin D deficiency was observed in our patients: 83.4% of them had levels below 30 ng/ml; they also presented an increased risk of cardiovascular disease, along with a high consumption of dietary fat. Factors related to the virus itself and to the use of antiretroviral drugs may have contributed for the low vitamin D levels seen in our HIV-1-infected patients.

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Serum 25-Hydroxyvitamin D and Bone Mineral Density in a Racially and Ethnically Diverse Group of Men

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jc.2007-1217 ◽

2008 ◽

Vol 93 (1) ◽

pp. 40-46 ◽

Cited By ~ 110

Author(s):

Marian T. Hannan ◽

Heather J. Litman ◽

Andre B. Araujo ◽

Christine E. McLennan ◽

Robert R. McLean ◽

...

Keyword(s):

Bone Mineral Density ◽

Vitamin D ◽

Ethnic Group ◽

Bone Mineral ◽

White Men ◽

Population Based ◽

Vitamin D Status ◽

Mineral Density ◽

Hydroxyvitamin D ◽

25 Hydroxyvitamin D

Abstract Context: Although racial and ethnic differences in vitamin D status and bone mineral density (BMD) are recognized, less is known about how differences in vitamin D status impact BMD, especially among men. Objective: Our objective was to examine the relation between serum 25-hydroxyvitamin D [25(OH)D] and BMD by race and ethnic group. Design: We conducted a population-based, observational survey. Participants: Participants included 1114 Black, Hispanic, and White men, 30–79 yr of age. Outcomes: We assessed 25(OH)D by a competitive protein binding assay and BMD by dual-energy x-ray absorptiometry. Results: Mean age ± sd of the 331 Black, 362 Hispanic, and 421 White men was 48 ± 12.8 yr. Mean 25(OH)D was lower among Black (25.0 ± 14.7 ng/ml) and Hispanic (32.9 ± 13.9 ng/ml) men compared with White men (37.4 ± 14.0 ng/ml, P < 0.01). A higher percentage of both Black (44%) and Hispanic (23%) men had levels of 25(OH)D in the lowest quartile, compared with 11% of White men (P < 0.001). After adjusting for age, height, and weight, only White men showed significant positive correlation between 25(OH)D and BMD (range of correlations, 0.00–0.14). Serum 25(OH)D was not associated with BMD in Black or Hispanic men at any bone site. Results were similar when adjusted for age only. Conclusions: Our findings confirm substantial racial and ethnic group differences in BMD and serum 25(OH)D in men. Serum 25(OH)D and BMD are significantly related to one another in White men only. This may have implications for evaluation of bone health and supplementation in men with low levels of 25(OH)D. Further understanding of the biological mechanisms for these differences between race and ethnic groups is needed.

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Low Plasma 25-Hydroxyvitamin D and Risk of Tobacco-Related Cancer

Clinical Chemistry ◽

10.1373/clinchem.2012.201939 ◽

2013 ◽

Vol 59 (5) ◽

pp. 771-780 ◽

Cited By ~ 65

Author(s):

Shoaib Afzal ◽

Stig E Bojesen ◽

Børge G Nordestgaard

Keyword(s):

Vitamin D ◽

Tobacco Smoke ◽

Population Based ◽

Lower Plasma ◽

Vitamin D Metabolism ◽

Hydroxyvitamin D ◽

Hazard Ratios ◽

25 Hydroxyvitamin D ◽

And Function

BACKGROUND Tobacco smoke chemicals may influence vitamin D metabolism and function, and conversely vitamin D may modify the carcinogenicity of tobacco smoke chemicals. We tested the hypothesis that lower plasma 25-hydroxyvitamin D [25(OH)D] is associated with a higher risk of tobacco-related cancer in the general population. METHODS A prospective population-based cohort of 9791 individuals from the Copenhagen City Heart Study who were free of cancer at baseline was followed from 1981–1983 until December 2008 with 100% complete follow-up. RESULTS During up to 28 years of follow-up, 1081 participants developed a tobacco-related cancer and 1506 developed other cancers. Decreasing 25(OH)D concentrations, subdivided by clinical categories or by seasonally adjusted percentile categories, were associated with increasing cumulative incidence of tobacco-related cancer (log-rank trend P = 2 × 10−6 and P = 5 × 10−9). Multivariable adjusted hazard ratios of tobacco-related cancer were 1.75 (95% CI, 1.33–2.30) for 25(OH)D <5 vs ≥20 ng/mL, and 2.07 (1.63–2.62) for ≤5th vs >66th percentile. Also, multivariable adjusted hazard ratios for a 50% reduction in 25(OH)D were 1.20 (1.13–1.28) for any tobacco-related cancer, 1.19 (95% CI, 1.09–1.31) for lung cancer, 1.44 (1.19–1.73) for head and neck cancer, 1.28 (1.06–1.54) for bladder cancer, 1.34 (1.04–1.73) for kidney cancer, and 0.95 (0.89–1.01) for other cancers. CONCLUSIONS Lower plasma 25(OH)D was associated with higher risk of tobacco-related cancers, but not with risk of other cancers.

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Vitamin D Status in a Rural Italian Population

Reports ◽

10.3390/reports5010001 ◽

2021 ◽

Vol 5 (1) ◽

pp. 1

Author(s):

Ornella Morsilli ◽

Raffaella Guerriero ◽

Luigi Palmieri ◽

Cinzia Lo Noce ◽

Tanja Zeller ◽

...

Keyword(s):

Vitamin D ◽

Critical Role ◽

Central Italy ◽

Hypovitaminosis D ◽

Solar Irradiation ◽

Italian Population ◽

Vitamin D Status ◽

Serum Samples ◽

Younger Women ◽

Hydroxyvitamin D

Vitamin D is known as an antirachitic factor, although it also plays a critical role in several nonskeletal diseases. In our study, we evaluated vitamin D status and sex, age and seasonal association in a general population cohort living in central Italy. Data from 1174 men and 2274 women aged 20–81 were analyzed, and stored serum samples were assayed for 25-hydroxyvitamin D (25(OH)D). Vitamin D was low in both sexes with values significantly lower in women than in men; furthermore, its deficiency was highly correlated with age. The younger men had just sufficient 25(OH)D levels (32.3 ng/mL ± 13.2), which decreased with increasing age. The younger women showed insufficient 25(OH)D levels (24.8 ng/mL ± 11.9) that, as with men, further decreased with increasing age. This study demonstrated that hypovitaminosis D may be a very frequent condition also in a rural central Italian area with remarkable solar irradiation throughout the year. Our data clearly indicated an evident seasonal trend: at the end of the winter, serum 25(OH)D levels of the examined cohort were below the official sufficient value for both adult sexes. Sufficient levels were just reached in summer for men and only at the end of summer for young women.

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Vitamin D in Follicular Fluid Correlates With the Euploid Status of Blastocysts in a Vitamin D Deficient Population

Frontiers in Endocrinology ◽

10.3389/fendo.2020.609524 ◽

2021 ◽

Vol 11 ◽

Author(s):

Ana Arnanz ◽

Neelke De Munck ◽

Ibrahim El Khatib ◽

Aşina Bayram ◽

Andrea Abdala ◽

...

Keyword(s):

Vitamin D ◽

Follicular Fluid ◽

Serum Levels ◽

Human Reproduction ◽

Serum Samples ◽

Preimplantation Genetic Testing ◽

Hydroxyvitamin D ◽

25 Hydroxyvitamin D ◽

Metabolite Measurement ◽

Deficient Group

ContextThe widespread distribution of the Vitamin D (VitD) receptor in reproductive tissues suggests an important role for VitD in human reproduction. The assessment of patient´s VitD is based on the 25-hydroxyvitamin D (25(OH)D) metabolite measurement. However, most of the circulating 25(OH)D is bound to either VitD-binding protein (VDBP) (88%) or albumin (12%) and less than 1% circulates free.ObjectiveTo determine a possible correlation between VitD levels in serum (S) and follicular fluid (FF) and blastocyst ploidy status in patients undergoing infertility treatment.MethodsA prospective observational study was performed including couples planned for preimplantation genetic testing for aneuploidies (PGT-A) from ART Fertility Clinics. Patients were classified according to their 25(OH)D-Serum levels: VitD deficient group <20 ng/ml and insufficient/replete ≥20 ng/ml defined as VitD non-deficient group.ResultsSerum samples and 226 FF from individual follicles were collected for 25(OH)D, bioavailable 25(OH)D, free 25(OH)D, and % free 25(OH)D measurement. 25(OH)D-Serum in VitD deficient and non-deficient were 13.2±4.0 ng/ml vs 32.3±9.2 ng/ml; p<0.001. FF from 40 and 74 biopsied blastocysts was analysed of which 52.5 and 60.8% were euploid (p = 0.428), respectively. In VitD deficient patients, mean 25(OH)D-FF, bioavailable 25(OH)D-FF, and free 25(OH)D-FF were higher in euploid vs aneuploid blastocysts (18.3±6.3 ng/ml vs 13.9±4.8 ng/ml; p = 0.040; 1.5±0.5 ng/ml vs 1.1±0.4 ng/ml; p = 0.015; 0.005±0.002 ng/ml vs 0.003±0.001 ng/ml; p = 0.023, respectively), whilst no differences were found in VitD non-deficient patients (37.9±12.3 ng/ml vs 40.6±13.7 ng/ml; p = 0.380; 3.1±1.1 ng/ml vs 3.3±1.2 ng/ml; p = 0.323; 0.01±0.003 ng/ml vs 0.01±0.004 ng/ml; p = 0.319, respectively).ConclusionVitD non-deficient patients have a significantly higher probability of obtaining a euploid blastocyst compared to VitD deficient patients (OR:33.36, p = 0.002).

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Surveillance evaluation of the standardization of assay values for serum total 25-hydroxyvitamin D concentration in Japan

Annals of Clinical Biochemistry International Journal of Laboratory Medicine ◽

10.1177/0004563218765570 ◽

2018 ◽

Vol 55 (6) ◽

pp. 647-656 ◽

Cited By ~ 2

Author(s):

Hiroshi Ihara ◽

Sachiko Kiuchi ◽

Takayuki Ishige ◽

Motoi Nishimura ◽

Kazuyuki Matsushita ◽

...

Keyword(s):

Vitamin D ◽

Pilot Study ◽

Surveillance Study ◽

Serum Samples ◽

Acceptance Criterion ◽

Average Percentage ◽

Hydroxyvitamin D ◽

Consensus Values ◽

Liquid Chromatography Tandem Mass ◽

25 Hydroxyvitamin D

Background To assess the vitamin D nutritional status, serum total 25-hydroxyvitamin D (25(OH)D) concentration is measured. We used six automated 25(OH)D immunoassays (AIAs) available in Japan and certified by the Vitamin D Standardization Program (VDSP) at the U.S. Center for Disease Control and Prevention to assess the concordance of the assay results. Methods Serum total 25(OH)D concentrations in SRM 972a and 20 serum samples from patients were determined using three liquid chromatography-tandem mass spectrometry (LC-MS/MS) and six AIAs (pilot study), and an additional 110 serum samples were assessed by the six AIAs (surveillance study). The assay bias from the results of LC-MS/MS by Chiba University or consensus values (i.e. average of six AIAs) was estimated using the procedure described in CLSI document EP09-A3. Results LC-MS/MS at Chiba University could completely separate 25(OH)D2, 25(OH)D3 and 3-epi-25(OH)D3, and the observed values including total 25(OH)D in SRM 972a were all within ±1·SD of the assigned values. All AIAs produced results greater than ±3·SD. In the pilot study, four of the six AIAs had an average percentage bias, as estimated by confidence interval (CI), larger than ±5% (acceptance criterion in CLSI); the bias converged from −6.5% to 3.2% after adjustment by LC-MS/MS. In the surveillance study, 25(OH)D concentrations in AIAs all adjusted to LC-MS/MS converged within ±5% from consensus values. However, some AIAs showed negative or positive bias from the consensus values. Conclusions Current AIAs in Japan continue to lack standardization. Manufacturers should implement quality assurance strategies so that their values more closely align to those of standard reference material 972a.

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MON-386 Determining Vitamin D Status: Analytical Variability Between Available Assays

Journal of the Endocrine Society ◽

10.1210/jendso/bvaa046.1696 ◽

2020 ◽

Vol 4 (Supplement_1) ◽

Author(s):

Azni Lihawa Abdul Wahab ◽

Hans Gerhard Schneider

Keyword(s):

Vitamin D ◽

Cross Reactivity ◽

Vitamin D Metabolites ◽

Vitamin D Status ◽

Serum Samples ◽

Hydroxyvitamin D ◽

Low Concentrations ◽

Strong Positive Relationship ◽

Liquid Chromatography Tandem Mass ◽

25 Hydroxyvitamin D

Abstract Clinical interest to evaluate serum 25-hydroxyvitamin D[25(OH)D] to assess Vitamin D status in health risks continue to increase exponentially over the last decade. Variability of 25(OH)D measurements remains controversial despite the international initiative Vitamin D Standardization Program (VDSP) to standardise the assays. The aim of the present study was to examine the correlation of 25(OH)D concentrations measured by different assays. We measured 25(OH)D using the new Abbott Alinity and DiaSorin LiaisonXL chemiluminescence immunoassays against the National Institute of Standards and Technology (NIST)-traceable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The immunoassay method were compared with the LC-MS/MS using Passing-Bablok regression and Bland-Altman analysis. Common 25(OH)D cut-point for classification of vitamin D deficiency was used to compare the different assays. 125 adult serum samples were randomly selected and measured 25(OH)D levels ranged between <10 nmol/L to 290 nmol/L as determined by LC-MS/MS. Compared to the LC-MS/MS, both immunoassays demonstrated strong positive relationship based on Passing-Bablok regression analysis. The results were as follows: Abbott Alinity = 0.85x + 1.29nmol/L, 95% CI: -2.39 to 5.03 (r=0.94); DiaSorin LiaisonXL= 0.74x + 2.54nmol/L, 95% CI: -2.53 to 6.18 (r=0.91). Despite apparent good correlation, the overall mean bias was -12.6% for Abbott Alinity and -24.4% for DiaSorin LiaisonXL assays. A higher percentage of patients were classified as vitamin D deficient (25(OH)D <50 nmol/L) using DiaSorin LiaisonXL (53%) followed by Abbott Alinity (49%), when compared with LC-MS/MS (34%). Using 25(OH)D ≥ 50nmol/L as “adequate” determined by LC-MS/MS method, 22% (18/82) and 28% (23/82) of patients were classified as “deficient” when analysed on Abbott Alinity and DiaSorin LiaisonXL respectively. Clinician should be aware of the inter-method variability among different Vitamin D assays despite standardization efforts. These differences could be due to cross-reactivity with 25(OH)D2 and vitamin D metabolites, such as 24,25(OH)2D and epimeric forms. 3-epi-25(OH)D is not separated chromatographically by the LC-MS/MS method used in this study. Therefore, the negative bias observed might be due to interference from the 3-epi-25(OH)D, whereby clinical significance is uncertain. It is present in low concentrations in adult human serum, 1 but seen in significant amounts in neonatal serum.2 It is advisable to monitor serum 25(OH)D level following treatment in the same laboratory. 1. Lensmeyer G, et al. The C-3 epimer of 25-hydroxyvitamin D3 is present in adult serum. JCEM 2012; 97: 163–8. 2. Singh RJ, et al. C-3 epimers can account for a significant portion of total circulating 25-hydroxyvitamin D in infants, complicating accurate measurement and interpretation of vitamin D status. JCEM 2006; 91: 3055-61.

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