1
|
Neville JJ, Palmieri T, Young AR. Physical Determinants of Vitamin D Photosynthesis: A Review. JBMR Plus 2021; 5:e10460. [PMID: 33553995 PMCID: PMC7839826 DOI: 10.1002/jbm4.10460] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 12/16/2020] [Accepted: 12/17/2020] [Indexed: 12/18/2022] Open
Abstract
Vitamin D synthesis by exposure of skin to solar ultraviolet radiation (UVR) provides the majority of this hormone that is essential for bone development and maintenance but may be important for many other health outcomes. This process, which is the only well-established benefit of solar UVR exposure, depends on many factors including genetics, age, health, and behavior. However, the most important factor is the quantity and quality of UVR reaching the skin. Vitamin D synthesis specifically requires ultraviolet B (UVB) radiation that is the minority component (<5%) of solar UVR. This waveband is also the most important for the adverse effects of solar exposure. The most obvious of which is sunburn (erythema), but UVB is also the main cause of DNA damage to the skin that is a prerequisite for most skin cancers. UVB at the Earth's surface depends on many physical and temporal factors such as latitude, altitude, season, and weather. Personal, cultural, and behavioral factors are also important. These include skin melanin, clothing, body surface area exposed, holiday habits, and sunscreen use. There is considerable disagreement in the literature about the role of some of these factors, possibly because some studies have been done by researchers with little understanding of photobiology. It can be argued that vitamin D supplementation obviates the need for solar exposure, but many studies have shown little benefit from this approach for a wide range of health outcomes. There is also increasing evidence that such exposure offers health benefits independently of vitamin D: the most important of which is blood-pressure reduction. In any case, public health advice must optimize risk versus benefit for solar exposure. It is fortunate that the individual UVB doses necessary for maintaining optimal vitamin D status are lower than those for sunburn, irrespective of skin melanin. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Jonathan J Neville
- St John's Institute of Dermatology, School of Basic & Medical Biosciences King's College London London United Kingdom
| | - Tommaso Palmieri
- St John's Institute of Dermatology, School of Basic & Medical Biosciences King's College London London United Kingdom
| | - Antony R Young
- St John's Institute of Dermatology, School of Basic & Medical Biosciences King's College London London United Kingdom
| |
Collapse
|
2
|
Teymoori-Rad M, Marashi SM. Vitamin D and Covid-19: From potential therapeutic effects to unanswered questions. Rev Med Virol 2020; 31:e2159. [PMID: 32856339 DOI: 10.1002/rmv.2159] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 08/06/2020] [Accepted: 08/08/2020] [Indexed: 12/12/2022]
Abstract
Evidence suggests that vitamin D supplementation could potentially be effective either in treatment or prevention of coronavirus disease 2019 (Covid-19). Indeed, several studies and trials have begun to investigate the impact of vitamin D supplementation on patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In this review, we focus on the potential mechanisms of vitamin D in the pathogenesis of Covid-19. We consider whether deficiency of vitamin D may be one of the underlying biological factors that could explain the excess mortality seen among non-Caucasians. We also raise several important questions which need to be addressed to provide a clear picture of the extent to which vitamin D supplementation may benefit patients with Covid-19, particularly those with underlying risk factors.
Collapse
Affiliation(s)
- Majid Teymoori-Rad
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Sayed Mahdi Marashi
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| |
Collapse
|
3
|
Pacifico L, Osborn JF, Bonci E, Pierimarchi P, Chiesa C. Association between Vitamin D Levels and Nonalcoholic Fatty Liver Disease: Potential Confounding Variables. Mini Rev Med Chem 2019; 19:310-332. [PMID: 30360708 DOI: 10.2174/1389557518666181025153712] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/16/2017] [Accepted: 08/25/2017] [Indexed: 02/06/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD), historically considered to be the hepatic component of the metabolic syndrome, is a spectrum of fat-associated liver conditions, in the absence of secondary causes, that may progress to nonalcoholic steatohepatitis (NASH), fibrosis, and cirrhosis. Disease progression is closely associated with body weight or fatness, dyslipidemia, insulin resistance, oxidative stress, and inflammation. Recently, vitamin D deficiency has been linked to the pathogenesis and severity of NAFLD because of vitamin D "pleiotropic" functions, with roles in immune modulation, cell differentiation and proliferation, and regulation of inflammation. Indeed, several studies have reported an association between vitamin D and NAFLD/NASH. However, other studies have failed to find an association. Therefore, we sought to critically review the current evidence on the association between vitamin D deficiency and NAFLD/NASH, and to analyze and discuss some key variables that may interfere with this evaluation, such as host-, environment-, and heritability-related factors regulating vitamin D synthesis and metabolism; definitions of deficient or optimal vitamin D status with respect to skeletal and nonskeletal outcomes including NAFLD/NASH; methods of measuring 25(OH)D; and methods of diagnosing NAFLD as well as quantifying adiposity, the cardinal link between vitamin D deficiency and NAFLD.
Collapse
Affiliation(s)
- Lucia Pacifico
- Policlinico Umberto I Hospital, Sapienza University of Rome, Viale Regina Elena, 324 00161-Rome, Italy
| | - John F Osborn
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Viale Regina Elena, 324 00161- Rome, Italy
| | - Enea Bonci
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena, 324 00161- Rome, Italy
| | - Pasquale Pierimarchi
- Institute of Translational Pharmacology, National Research Council, Via Fosso del Cavaliere, 100 00133- Rome, Italy
| | - Claudio Chiesa
- Institute of Translational Pharmacology, National Research Council, Via Fosso del Cavaliere, 100 00133- Rome, Italy
| |
Collapse
|
4
|
Tayie F, Wu C. Large Bone not Necessarily High Bone Mineral Density: Evidence from a National Survey. Calcif Tissue Int 2019; 104:145-151. [PMID: 30244339 DOI: 10.1007/s00223-018-0479-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Accepted: 09/19/2018] [Indexed: 11/27/2022]
Abstract
There is scarcity of population-level data on the bone areal size (BA) that produces the highest bone mineral density (BMD), and how BA relates to BMD among racial groups. We use population-level data to estimate the BA that coincide with the highest BMD among racial groups in the United States. A total of 7425 participants, age 18-75 years, whose BA and BMD were measured in the United States National Health and Nutrition Examination Survey (NHANES) 2009-2014, were assessed in this study. Multiple regression models were used to estimate race-specific relationships between BA and BMD. The critical BA that associates with the highest (peak) BMD among racial groups adjusted for confounders was estimated. Results showed a curvilinear relationship between BA and BMD at the population level such that BMD increases with BA at lower values and then decreases after a peak value. Races combined, BA of about 45 cm2 seems to correspond to a peak femur BMD in this sample. The peak BMD was different among racial groups. The BA at which BMD peaks was lower among blacks and Mexicans compared to whites. We conclude that femur BMD increases up to a critical femur BA and then decreases thereafter. Persons with femur BA at or close to the critical value may tend to have higher than average BMD.
Collapse
Affiliation(s)
- Francis Tayie
- Southeast Missouri State University, Cape Girardeau, USA.
| | - Chen Wu
- Southeast Missouri State University, Cape Girardeau, USA
| |
Collapse
|
5
|
Datta P, Philipsen PA, Olsen P, Petersen B, Andersen JD, Morling N, Wulf HC. Pigment genes not skin pigmentation affect UVB-induced vitamin D. Photochem Photobiol Sci 2019; 18:448-458. [DOI: 10.1039/c8pp00320c] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The long-term UVB induced serum 25(OH)D increase was influenced by pigment gene polymorphisms rather than measured facultative skin pigmentation.
Collapse
Affiliation(s)
- Pameli Datta
- Department of Dermatology D92
- Copenhagen University Hospital
- Bispebjerg Hospital
- 2400 Copenhagen
- Denmark
| | - Peter Alshede Philipsen
- Department of Dermatology D92
- Copenhagen University Hospital
- Bispebjerg Hospital
- 2400 Copenhagen
- Denmark
| | - Peter Olsen
- Department of Dermatology D92
- Copenhagen University Hospital
- Bispebjerg Hospital
- 2400 Copenhagen
- Denmark
| | - Bibi Petersen
- Department of Dermatology D92
- Copenhagen University Hospital
- Bispebjerg Hospital
- 2400 Copenhagen
- Denmark
| | - Jeppe Dyrberg Andersen
- Section of Forensic Genetics
- Department of Forensic Medicine
- Faculty of Health and Medical Sciences
- University of Copenhagen
- 2100 Copenhagen
| | - Niels Morling
- Section of Forensic Genetics
- Department of Forensic Medicine
- Faculty of Health and Medical Sciences
- University of Copenhagen
- 2100 Copenhagen
| | - Hans Christian Wulf
- Department of Dermatology D92
- Copenhagen University Hospital
- Bispebjerg Hospital
- 2400 Copenhagen
- Denmark
| |
Collapse
|
6
|
Waziri B, Duarte R, Dickens C, Dix Peek T, George J, Rekhviashvili V, Paget G, Naicker S. Racial Variations in the Markers of Mineral Bone Disorders in CKD Patients in South Africa. Kidney Int Rep 2017; 3:583-591. [PMID: 29854965 PMCID: PMC5976813 DOI: 10.1016/j.ekir.2017.12.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 11/13/2017] [Accepted: 12/06/2017] [Indexed: 01/14/2023] Open
Abstract
Introduction Several studies showed that serum intact parathyroid hormone (PTH), phosphate, and vitamin D levels differ across races. These comparative studies were largely carried out between Caucasians and black Americans. However, little is known of the existence of these associations in an African population with chronic kidney disease (CKD). Methods This cross-sectional multicenter study involved 293 CKD patients from 3 renal units in Johannesburg, South Africa. Results The 293 CKD patients (208 blacks, 85 whites) had an overall mean age of 51.1 ± 13.6 years, and black patients were significantly younger than the white patients (48.4 ± 13.6 years vs. 57.1 ± 15.5 years; P < 0.001). Compared with whites, blacks had higher median intact PTH (498 [range: 37–1084] pg/ml vs. 274 [range: 131–595] pg/ml; P = 0.03), alkaline phosphatase (122 [range: 89–192] U/L vs. 103 [range: 74–144] U/L; p = 0.03), and mean 25 OH vitamin D3 (26.8 ± 12.7 ng/ml vs. 22.7 ± 12.2 ng/ml, P = 0.01) levels, whereas their median fibroblast growth factor (FGF) level was 23 (100 [range: 34–639] pg/ml vs. 233 [range: 80–1370] pg/ml; P = 0.002), and their mean serum phosphate (1.3 ± 0.5 vs. 1.5 ± 0.5; P = 0.001) levels were significantly lower. In multivariable analyses, black race was independently associated with increased log PTH (β = 0.488, P = 0.01) and decreased log FGF-23 (β = −0.636, P = 0.02). Similarly, blacks had a 3.08 times higher likelihood (95% confidence interval: 1.51–6.30; P = 0.002) of developing severe hyperparathyroidism than whites. Conclusion This study highlighted the existence of racial differences in the circulating markers of mineral bone disorders in an African CKD population.
Collapse
Affiliation(s)
- Bala Waziri
- Department of Internal Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Raquel Duarte
- Department of Internal Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Caroline Dickens
- Department of Internal Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Therese Dix Peek
- Department of Internal Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Jaya George
- Department of Chemical Pathology, National Health Laboratory Services, University of the Witwatersrand, Johannesburg, South Africa
| | - Vakhtang Rekhviashvili
- Renal Unit, Donald Gordon Medical Center, University of the Witwatersrand, Johannesburg, South Africa
| | - Graham Paget
- Department of Internal Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Saraladevi Naicker
- Department of Internal Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| |
Collapse
|
7
|
Al-Daghri NM, Al-Saleh Y, Khan N, Sabico S, Aljohani N, Alfawaz H, Alsulaimani M, Al-Othman AM, Alokail MS. Sun exposure, skin color and vitamin D status in Arab children and adults. J Steroid Biochem Mol Biol 2016; 164:235-238. [PMID: 27182012 DOI: 10.1016/j.jsbmb.2016.05.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 05/04/2016] [Accepted: 05/12/2016] [Indexed: 12/19/2022]
Abstract
Accumulating evidence suggests an increased prevalence of vitamin D deficiency in the Middle East and North African countries. Sunlight has long been recognized as a major provider of vitamin D and lighter skin color has been associated with better vitamin D status. In this context, we aimed to determine whether 25-hydroxyvitamin D[25-(OH)D] concentrations are related to skin color, sun exposure and gender among healthy Saudi children and adults. A total of 808 Saudi children (age=14.6±0.04years) and 561 (age=31.4±0.3years) adults of both genders were included in this study. Levels of sun exposure and skin color were determined using a standard questionnaire. Anthropometry and plasma 25-(OH)D concentrations were analyzed. On the basis of duration of sun exposure (<20min vs. >20min), a significantly lower concentration of 25-(OH)D (40.9±1.2 vs. 35.5±1.8nmol/l; p<0.019) was demonstrated in dark-skinned boys with exposure time less than 20min than those exposed longer than 20min. We were unable to show an effect of sunlight exposure or skin color on vitamin D status of children or adults, except in dark-skinned boys who had lower 25(OH)D concentrations associated with limited sun exposure.
Collapse
Affiliation(s)
- Nasser M Al-Daghri
- Prince Mutaib Chair for Biomarkers of Osteoporosis, King Saud University, Saudi Arabia; Biomarkers Research Program, Biochemistry Department, College of Science, King Saud University, Saudi Arabia.
| | - Yousef Al-Saleh
- Prince Mutaib Chair for Biomarkers of Osteoporosis, King Saud University, Saudi Arabia; King Abdulaziz Medical City, College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Riyadh 11426, Saudi Arabia
| | - Nasiruddin Khan
- Prince Mutaib Chair for Biomarkers of Osteoporosis, King Saud University, Saudi Arabia; Biomarkers Research Program, Biochemistry Department, College of Science, King Saud University, Saudi Arabia
| | - Shaun Sabico
- Prince Mutaib Chair for Biomarkers of Osteoporosis, King Saud University, Saudi Arabia; Biomarkers Research Program, Biochemistry Department, College of Science, King Saud University, Saudi Arabia
| | - Naji Aljohani
- Specialized Diabetes and Endocrine Center, King Fahad Medical City, Faculty of Medicine, King Saud Bin Abdulaziz University for Health Science (KSAU-HS), Riyadh, Saudi Arabia
| | - Hanan Alfawaz
- Prince Mutaib Chair for Biomarkers of Osteoporosis, King Saud University, Saudi Arabia; College of Food Science & Agriculture, Dept. of Food Science & Nutrition, King Saud University, Riyadh, Saudi Arabia
| | - Maha Alsulaimani
- Biochemistry Department, College of Science, King Saud University, Saudi Arabia
| | - Abdulaziz M Al-Othman
- Prince Mutaib Chair for Biomarkers of Osteoporosis, King Saud University, Saudi Arabia; College of Applied Medical Sciences, King Saud University, Saudi Arabia
| | - Majed S Alokail
- Prince Mutaib Chair for Biomarkers of Osteoporosis, King Saud University, Saudi Arabia; Biomarkers Research Program, Biochemistry Department, College of Science, King Saud University, Saudi Arabia
| |
Collapse
|
8
|
Elias PM, Williams ML. Basis for the gain and subsequent dilution of epidermal pigmentation during human evolution: The barrier and metabolic conservation hypotheses revisited. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2016; 161:189-207. [PMID: 27324932 DOI: 10.1002/ajpa.23030] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 05/27/2016] [Accepted: 05/29/2016] [Indexed: 12/25/2022]
Abstract
The evolution of human skin pigmentation must address both the initial evolution of intense epidermal pigmentation in hominins, and its subsequent dilution in modern humans. While many authorities believe that epidermal pigmentation evolved to protect against either ultraviolet B (UV-B) irradiation-induced mutagenesis or folic acid photolysis, we hypothesize that pigmentation augmented the epidermal barriers by shifting the UV-B dose-response curve from toxic to beneficial. Whereas erythemogenic UV-B doses produce apoptosis and cell death, suberythemogenic doses benefit permeability and antimicrobial function. Heavily melanized melanocytes acidify the outer epidermis and emit paracrine signals that augment barrier competence. Modern humans, residing in the cooler, wetter climes of south-central Europe and Asia, initially retained substantial pigmentation. While their outdoor lifestyles still permitted sufficient cutaneous vitamin D3 (VD3) synthesis, their marginal nutritional status, coupled with cold-induced caloric needs, selected for moderate pigment reductions that diverted limited nutritional resources towards more urgent priorities (=metabolic conservation). The further pigment-dilution that evolved as humans reached north-central Europe (i.e., northern France, Germany), likely facilitated cutaneous VD3 synthesis, while also supporting ongoing, nutritional requirements. But at still higher European latitudes where little UV-B breaches the atmosphere (i.e., present-day UK, Scandinavia, Baltic States), pigment dilution alone could not suffice. There, other nonpigment-related mutations evolved to facilitate VD3 production; for example, in the epidermal protein, filaggrin, resulting in reduced levels of its distal metabolite, trans-urocanic acid, a potent UV-B chromophore. Thus, changes in human pigmentation reflect a complex interplay between latitude, climate, diet, lifestyle, and shifting metabolic priorities.
Collapse
Affiliation(s)
- Peter M Elias
- Department of Veterans Affairs Medical Center, Dermatology Service, University of California San Francisco, California. .,Department of Dermatology, Dermatology Service, University of California San Francisco, California.
| | - Mary L Williams
- Department of Dermatology, University of California, San Francisco, California.,Department of Pediatrics, University of California, San Francisco, California
| |
Collapse
|
9
|
Lee DE, Trowbridge RM, Ayoub NT, Agrawal DK. High-mobility Group Box Protein-1, Matrix Metalloproteinases, and Vitamin D in Keloids and Hypertrophic Scars. PLASTIC AND RECONSTRUCTIVE SURGERY-GLOBAL OPEN 2015; 3:e425. [PMID: 26180726 PMCID: PMC4494495 DOI: 10.1097/gox.0000000000000391] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 04/23/2015] [Indexed: 01/16/2023]
Abstract
Keloids and hypertrophic scars represent excessive wound healing involving high production of collagen by skin fibroblasts. This review focuses on the role of high-mobility group box protein-1 (HMGB-1), matrix metalloproteinases (MMPs), and vitamin D in these conditions. Although the role of HMGB-1 in keloids and hypertrophic scars is unclear, the effect of HMGB-1 on fibroblasts suggests a profibrotic role and a potential contribution to excessive scarring. MMPs contribute extensively to wound healing and characteristically degrade the extracellular matrix. MMP-1 is decreased in keloids and hypertrophic scars. However, other MMPs, including MMP-2, have been found to be increased and are thought to possibly contribute to keloid expansion through peripheral extracellular matrix catabolism. Many novel therapeutic approaches to keloids and hypertrophic scars target MMPs and aim to increase their levels and catabolic activity. The higher prevalence of keloids in darker skin types may partially be due to a tendency for lower vitamin D levels. The physiologically active form of vitamin D, 1,25(OH)2D3, inhibits the proliferation of keloid fibroblasts, and correlations between vitamin D receptor polymorphisms, such as the TaqI CC genotype, and keloid formation have been reported. Additionally, vitamin D may exert an antifibrotic effect partially mediated by MMPs. Here, we critically discuss whether keloid and hypertrophic scar formation could be predicted based on vitamin D status and vitamin D receptor polymorphisms. Specifically, the findings identified HMGB-1, MMPs, and vitamin D as potential avenues for further clinical investigation and potentially novel therapeutic approaches to prevent the development of keloids and hypertrophic scars.
Collapse
Affiliation(s)
- Dylan E. Lee
- From the Center for Clinical and Translational Science, Creighton University School of Medicine, Omaha, Neb.; Brigham and Women’s Hospital, Boston, Mass.; and Westfield Plastic Surgery Center, Omaha, Neb
| | - Ryan M. Trowbridge
- From the Center for Clinical and Translational Science, Creighton University School of Medicine, Omaha, Neb.; Brigham and Women’s Hospital, Boston, Mass.; and Westfield Plastic Surgery Center, Omaha, Neb
| | - Nagi T. Ayoub
- From the Center for Clinical and Translational Science, Creighton University School of Medicine, Omaha, Neb.; Brigham and Women’s Hospital, Boston, Mass.; and Westfield Plastic Surgery Center, Omaha, Neb
| | - Devendra K. Agrawal
- From the Center for Clinical and Translational Science, Creighton University School of Medicine, Omaha, Neb.; Brigham and Women’s Hospital, Boston, Mass.; and Westfield Plastic Surgery Center, Omaha, Neb
| |
Collapse
|
10
|
Franchi B, Piazza M, Sandri M, Tenero L, Comberiati P, Boner AL, Capristo C. 25-hydroxyvitamin D serum level in children of different ethnicity living in Italy. Eur J Pediatr 2015; 174:749-57. [PMID: 25398616 DOI: 10.1007/s00431-014-2451-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 10/18/2014] [Accepted: 10/23/2014] [Indexed: 12/26/2022]
Abstract
UNLABELLED Several factors including ethnicity are known to influence 25(OH)D levels. The purpose of our study was to assess 25(OH)D levels among 1374 pediatric subjects of different ethnicity and to determine the prevalence of vitamin D deficiency and insufficiency among different ethnic groups. The prevalence of 25(OH)D ≤ 20 ng/ml was 44.2, 65.2, 69.2, 54.0, and 44.8 % among Caucasians, Africans, North Africans, Indians, and others, respectively (P < 0.001). The median of 25(OH)D was 21.0 ng/ml (IQR = 14.0-29.6 ng/ml) for the cohort. Season of blood sampling, age, ethnicity, gestational age, birth weight, and z-score BMI were associated with 25(OH)D levels. Caucasians had higher median 25(OH)D levels than sub-Saharan Africans (P < 0.001), North Africans (P < 0.001), and Indians (P < 0.001). There were no significant differences in the median 25(OH)D levels between ethnic groups among infants, whereas for children older than 1 year we found significant differences in 25(OH)D levels in the different ethnic groups, compared to Caucasians. CONCLUSION Ethnicity was correlated with 25(OH)D levels among children older than 1 year. We found a high prevalence of vitamin D deficiency and insufficiency after the first year of life, and this was more remarkable in non-Caucasian children.
Collapse
Affiliation(s)
- Bruna Franchi
- Department of Life and Reproduction Sciences, Pediatrics Section, University of Verona, Policlinico G.B. Rossi, Piazzale L.A. Scuro 10, Verona, 37134, Italy,
| | | | | | | | | | | | | |
Collapse
|
11
|
Xiang F, Lucas R, de Gruijl F, Norval M. A systematic review of the influence of skin pigmentation on changes in the concentrations of vitamin D and 25-hydroxyvitamin D in plasma/serum following experimental UV irradiation. Photochem Photobiol Sci 2015; 14:2138-46. [DOI: 10.1039/c5pp00168d] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Does skin colour influence the production of vitamin D metabolites following UV irradiation? The paper reviews the studies addressing this important question and discusses possible reasons for the contradictory results.
Collapse
Affiliation(s)
- Fan Xiang
- National Centre for Epidemiology and Population Health
- The Australian National University
- Canberra
- Australia
| | - Robyn Lucas
- National Centre for Epidemiology and Population Health
- The Australian National University
- Canberra
- Australia
| | - Frank de Gruijl
- Department of Dermatology
- Leiden University Medical Centre
- NL-2300 RC Leiden
- Netherlands
| | - Mary Norval
- Biomedical Sciences
- University of Edinburgh Medical School
- Edinburgh
- UK
| |
Collapse
|
12
|
Kearns MD, Tangpricha V. The role of vitamin D in tuberculosis. JOURNAL OF CLINICAL AND TRANSLATIONAL ENDOCRINOLOGY 2014; 1:167-169. [PMID: 29159097 PMCID: PMC5684962 DOI: 10.1016/j.jcte.2014.08.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Malcolm D Kearns
- Division of Endocrinology, Metabolism and Lipids, Emory University School of Medicine, Atlanta, GA, USA
| | - Vin Tangpricha
- Division of Endocrinology, Metabolism and Lipids, Emory University School of Medicine, Atlanta, GA, USA
| |
Collapse
|
13
|
Abstract
The prevalence of osteoporosis and the incidence of age-related fragility fracture vary by ethnicity. There is greater than 10-fold variation in fracture probabilities between countries across the world. Mineral and bone metabolism are intimately interlinked, and both are known to exhibit patterns of daily variation, known as the diurnal rhythm (DR). Ethnic differences are described for Ca and P metabolism. The importance of these differences is described in detail between select ethnic groups, within the USA between African-Americans and White-Americans, between the Gambia and the UK and between China and the UK. Dietary Ca intake is higher in White-Americans compared with African-Americans, and is higher in White-British compared with Gambian and Chinese adults. Differences are observed also for plasma 25-hydroxy vitamin D, related to lifestyle differences, skin pigmentation and skin exposure to UVB-containing sunshine. Higher plasma 1,25-dihydroxy vitamin D and parathyroid hormone are observed in African-American compared with White-American adults. Plasma parathyroid hormone is also higher in Gambian adults and, in winter, in Chinese compared with White-British adults. There may be ethnic differences in the bone resorptive effects of parathyroid hormone, with a relative skeletal resistance to parathyroid hormone observed in some, but not all ethnic groups. Renal mineral excretion is also influenced by ethnicity; urinary Ca (uCa) and urinary P (uP) excretions are lower in African-Americans compared with White-Americans, and in Gambians compared with their White-British counterparts. Little is known about ethnic differences in the DR of Ca and P metabolism, but differences may be expected due to known differences in lifestyle factors, such as dietary intake and sleep/wake pattern. The ethnic-specific DR of Ca and P metabolism may influence the net balance of Ca and P conservation and bone remodelling. These ethnic differences in Ca, P and the bone metabolism may be important factors in the variation in skeletal health.
Collapse
Affiliation(s)
- J. Redmond
- Elsie Widdowson Laboratory, Medical Research Council Human Nutrition Research, Cambridge CB1 9NL, UK
| | | | - B. Zhou
- Department of Public health, Shenyang Medical College, 146 Huanghe North Street, Shenyang 110034, People's Republic of China
| | - A. Prentice
- Elsie Widdowson Laboratory, Medical Research Council Human Nutrition Research, Cambridge CB1 9NL, UK
- Medical Research Council Keneba, The Gambia
| | - I. Schoenmakers
- Elsie Widdowson Laboratory, Medical Research Council Human Nutrition Research, Cambridge CB1 9NL, UK
| |
Collapse
|
14
|
Elias PM, Williams ML. Re-appraisal of current theories for the development and loss of epidermal pigmentation in hominins and modern humans. J Hum Evol 2013; 64:687-92. [PMID: 23478159 PMCID: PMC3654079 DOI: 10.1016/j.jhevol.2013.02.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 02/04/2013] [Accepted: 02/05/2013] [Indexed: 12/29/2022]
Affiliation(s)
- Peter M Elias
- Dermatology Service, Department of Veterans Affairs Medical Center, 4150 Clement Street, MS 190, San Francisco, CA 94121, USA.
| | | |
Collapse
|
15
|
Castro LCGD. [The vitamin D endocrine system]. ACTA ACUST UNITED AC 2012; 55:566-75. [PMID: 22218438 DOI: 10.1590/s0004-27302011000800010] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2011] [Accepted: 10/21/2011] [Indexed: 01/18/2023]
Abstract
The vitamin D endocrine system comprises a group of 7-dehydrocholesterol-derived secosteroid molecules, including its active metabolite 1,25-dihydroxy-vitamin D (1,25(OH)(2)D), its precursors and other metabolites, its binding protein (DBP) and nuclear receptor (VDR), as well as cytochrome P450 complex enzymes participating in activation and inactivation pathways of those molecules. The biologic effects of 1,25(OH)(2)D are mediated by VDR, a ligand-activated transcription factor which is a member of the nuclear receptors family, spread in almost all human cells. In addition to its classic role in the regulation of calcium metabolism and bone health, evidence suggests that 1,25(OH)(2)D directly or indirectly modulates about 3% of the human genome, participating in the regulation of chief functions of systemic homeostasis, such as cell growth, differentiation and apoptosis, regulation of immune, cardiovascular and musculoskeletal systems, and insulin metabolism. Given the critical influence of the vitamin D endocrine system in many processes of systemic metabolic equilibrium, the laboratory assays available for the evaluation of this system have to present high accuracy and reproducibility, enabling the establishment of cutoff points that, beyond being consensually accepted, reliably express the vitamin D status of the organism, and the respective clinical-metabolic impacts on the global health of the individual.
Collapse
|
16
|
Vitamin D intake, vitamin D receptor polymorphisms, and breast cancer risk among women living in the southwestern U.S. Breast Cancer Res Treat 2011; 132:683-91. [PMID: 22130867 DOI: 10.1007/s10549-011-1885-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Accepted: 11/12/2011] [Indexed: 10/15/2022]
Abstract
No studies of dietary vitamin D intake and vitamin D receptor (VDR) have been conducted comparing breast risk among Hispanic women and non-Hispanic white (NHW) women. We investigated the association between vitamin D intake and breast cancer in a population-based case-control study of 1,527 NHW and 791 Hispanic breast cancer cases diagnosed in 1999-2004 in Arizona, New Mexico, Utah, and Colorado, and 1,599 NHW and 922 Hispanic age-matched controls. Vitamin D intake was assessed using food frequency questionnaires, and associations with breast cancer were adjusted for age, ethnicity, state, education, body mass index, smoking, age at menarche, age at first birth, parity, hormone exposure, height, and physical activity using logistic regression. BsmI, Poly A and FokI vitamin D receptor (VDR) genotypes were also measured. Dietary vitamin D intake was positively associated with breast cancer (highest vs. lowest quartile (Q (4) vs. Q (1)): odds ratio (OR) = 1.35, 95% confidence interval (CI) = 1.15-1.60; P (trend) = 0.003), whereas vitamin D supplement use was inversely associated with breast cancer (10+ μg/day vs. none: OR = 0.79, 95% CI = 0.65-0.96, P (trend) = 0.01). Similar patterns in risk were observed by ethnicity and menopausal status. Positive associations with dietary vitamin D intake and inverse associations with supplement use were observed for ER+/PR+ and ER-/PR- breast cancers, but not for ER+/PR- disease. BsmI genotype significantly modified the association between dietary vitamin D and breast cancer overall. Future research is needed to better understand potential differences in breast cancer risk by vitamin D source and hormone receptor status.
Collapse
|
17
|
Wilson RT, Roff AN, Dai PJ, Fortugno T, Douds J, Chen G, Grove GL, Nikiforova SO, Barnholtz-Sloan J, Frudakis T, Chinchilli VM, Hartman TJ, Demers LM, Shriver MD, Canfield VA, Cheng KC. Genetic Ancestry, Skin Reflectance and Pigmentation Genotypes in Association with Serum Vitamin D Metabolite Balance. Horm Mol Biol Clin Investig 2011; 7:279-293. [PMID: 23525585 DOI: 10.1515/hmbci.2011.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Lower serum vitamin D (25(OH)D) among individuals with African ancestry is attributed primarily to skin pigmentation. However, the influence of genetic polymorphisms controlling for skin melanin content has not been investigated. Therefore, we investigated differences in non-summer serum vitamin D metabolites according to self-reported race, genetic ancestry, skin reflectance and key pigmentation genes (SLC45A2 and SLC24A5). MATERIALS AND METHODS Healthy individuals reporting at least half African American or half European American heritage were frequency matched to one another on age (+/- 2 years) and sex. 176 autosomal ancestry informative markers were used to estimate genetic ancestry. Melanin index was measured by reflectance spectrometry. Serum vitamin D metabolites (25(OH)D3, 25(OH)D 2 and 24,25(OH)2D3) were determined by high performance liquid chromatography (HPLC) tandem mass spectrometry. Percent 24,25(OH)2D3 was calculated as a percent of the parent metabolite (25(OH)D3). Stepwise and backward selection regression models were used to identify leading covariates. RESULTS Fifty African Americans and 50 European Americans participated in the study. Compared with SLC24A5 111Thr homozygotes, individuals with the SLC24A5 111Thr/Ala and 111Ala/Ala genotypes had respectively lower levels of 25(OH)D3 (23.0 and 23.8 nmol/L lower, p-dominant=0.007), and percent 24,25(OH)2D3 (4.1 and 5.2 percent lower, p-dominant=0.003), controlling for tanning bed use, vitamin D/fish oil supplement intake, race/ethnicity, and genetic ancestry. Results were similar with melanin index adjustment, and were not confounded by glucocorticoid, oral contraceptive, or statin use. CONCLUSIONS The SLC24A5 111Ala allele was associated with lower serum vitamin 25(OH)D3 and lower percent 24,25(OH)2D3, independently from melanin index and West African genetic ancestry.
Collapse
Affiliation(s)
- Robin Taylor Wilson
- Penn State Hershey College of Medicine, and Penn State Hershey Cancer Institute, The Pennsylvania State University, Hershey, Pennsylvania, U.S.A
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Vélayoudom-Céphise FL, Larifla L, Donnet JP, Maimaitiming S, Deloumeaux J, Blanchet A, Massart C, Munoz-Bellili N, Merle S, Chout R, Bonnet F, Foucan L. Vitamin D deficiency, vitamin D receptor gene polymorphisms and cardiovascular risk factors in Caribbean patients with type 2 diabetes. DIABETES & METABOLISM 2011; 37:540-5. [PMID: 21764620 DOI: 10.1016/j.diabet.2011.05.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Revised: 05/30/2011] [Accepted: 05/31/2011] [Indexed: 10/18/2022]
Abstract
AIM The prevalence of diabetes in the French West Indies is three times higher than in mainland France. We aimed to assess the associations between vitamin D deficiency, vitamin D receptor (VDR) gene polymorphisms and cardiovascular risk factors in Caribbean patients with type 2 diabetes (T2D). METHODS In this cross-sectional study of 277 patients, 25-hydroxyvitamin D was measured by radioimmunoassay. FokI, BsmI, ApaI and TaqI single nucleotide polymorphisms (SNPs) of the VDR gene were genotyped. Analysis of covariance and logistic regression were performed. RESULTS The study included 76 patients of Indian descent and 201 patients of African descent. The prevalence of vitamin D deficiency (<20 ng/mL) was 42.6%. When patients were classified into groups with (G1) and without (G2) vitamin D deficiency, there were no significant differences in age, systolic blood pressure, low-density lipoprotein cholesterol and HbA(1c), although body mass index was significantly higher in G1. Vitamin D deficiency was significantly associated with increased diastolic blood pressure and triglyceride levels, and reduced high-density lipoprotein cholesterol (P<0.05). Prevalence of vitamin D deficiency was decreased in patients carrying the f allele of FokI (OR: 0.52; P=0.02) and the aa genotype of ApaI (OR: 0.46; P=0.05). BsmI and TaqI SNPs were not associated with vitamin D deficiency. CONCLUSION The rate of vitamin D deficiency was high in our T2D patients, and was associated with the VDR gene FokI and ApaI polymorphisms and cardiovascular risk profile. Measurements of vitamin D may help to detect T2D patients with cardiovascular risk, and VDR polymorphisms might explain why vitamin D deficiency is so frequently seen in some T2D patients.
Collapse
Affiliation(s)
- F-L Vélayoudom-Céphise
- Research Group, Clinical Epidemiology and Medicine, University Hospital of Guadeloupe, University of Antilles and Guyane, France
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Springbett P, Buglass S, Young AR. Photoprotection and vitamin D status. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2010; 101:160-8. [PMID: 20444619 DOI: 10.1016/j.jphotobiol.2010.03.006] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Revised: 03/17/2010] [Accepted: 03/18/2010] [Indexed: 01/04/2023]
|
20
|
Björn LO. Vitamin D synthesis may be independent of skin pigmentation only with UV of short wavelength. J Invest Dermatol 2010; 130:2848-50. [PMID: 20861850 DOI: 10.1038/jid.2010.228] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
21
|
Signorello LB, Williams SM, Zheng W, Smith JR, Long J, Cai Q, Hargreaves MK, Hollis BW, Blot WJ. Blood vitamin d levels in relation to genetic estimation of African ancestry. Cancer Epidemiol Biomarkers Prev 2010; 19:2325-31. [PMID: 20647395 DOI: 10.1158/1055-9965.epi-10-0482] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND African-Americans generally have lower circulating levels of 25 hydroxyvitamin D [25(OH)D] than Whites, attributed to skin pigmentation and dietary habits. Little is known about the genetic determinants of 25(OH)D levels nor whether the degree of African ancestry associates with circulating 25(OH)D. METHODS With the use of a panel of 276 ancestry informative genetic markers, we estimated African and European admixture for a sample of 758 African-American and non-Hispanic White Southern Community Cohort Study participants. For African-Americans, cut points of <85%, 85% to 95%, and >or=95% defined low, medium, and high African ancestry, respectively. We estimated the association between African ancestry and 25(OH)D and also explored whether vitamin D exposure (sunlight, diet) had varying effects on 25(OH)D levels dependent on ancestry level. RESULTS The mean serum 25(OH)D levels among Whites and among African-Americans of low, medium, and high African ancestry were 27.2, 19.5, 18.3, and 16.5 ng/mL, respectively. Serum 25(OH)D was estimated to decrease by 1.0 to 1.1 ng/mL per 10% increase in African ancestry. The effect of high vitamin D exposure from sunlight and diet was 46% lower among African-Americans with high African ancestry than among those with low/medium ancestry. CONCLUSIONS We found novel evidence that the level of African ancestry may play a role in clinical vitamin D status. IMPACT This is the first study to describe how 25(OH)D levels vary in relation to genetic estimation of African ancestry. Further study is warranted to replicate these findings and uncover the potential pathways involved.
Collapse
Affiliation(s)
- Lisa B Signorello
- 1International Epidemiology Institute, Rockville, Maryland 20850, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Robins AH. The evolution of light skin color: role of vitamin D disputed. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2009; 139:447-50. [PMID: 19425095 DOI: 10.1002/ajpa.21077] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Ashley H Robins
- Department of Medicine, Division of Pharmacology, University of Cape Town Medical School, Observatory, South Africa 7925.
| |
Collapse
|
23
|
Bogh MKB, Schmedes AV, Philipsen PA, Thieden E, Wulf HC. Vitamin D production after UVB exposure depends on baseline vitamin D and total cholesterol but not on skin pigmentation. J Invest Dermatol 2009; 130:546-53. [PMID: 19812604 DOI: 10.1038/jid.2009.323] [Citation(s) in RCA: 157] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
UVB radiation increases serum vitamin D level expressed as 25-hydroxyvitamin-D(3) (25(OH)D), but the influence of skin pigmentation, baseline 25(OH)D level, and total cholesterol has not been well characterized. To determine the importance of skin pigmentation, baseline 25(OH)D level, and total cholesterol on 25(OH)D production after UVB exposure, 182 persons were screened for 25(OH)D level. A total of 50 participants with a wide range in baseline 25(OH)D levels were selected to define the importance of baseline 25(OH)D level. Of these, 28 non-sun worshippers with limited past sun exposure were used to investigate the influence of skin pigmentation and baseline total cholesterol. The participants had 24% of their skin exposed to UVB (3 standard erythema doses) four times every second or third day. Skin pigmentation and 25(OH)D levels were measured before and after the irradiations. Total cholesterol was measured at baseline. The increase in 25(OH)D level after UVB exposure was negatively correlated with baseline 25(OH)D level (P<0.001) and positively correlated with baseline total cholesterol level (P=0.005), but no significant correlations were found with constitutive or facultative skin pigmentation. In addition, we paired a dark-skinned group with a fair-skinned group according to baseline 25(OH)D levels and found no differences in 25(OH)D increase after identical UVB exposure.
Collapse
Affiliation(s)
- Morten K B Bogh
- Department of Dermatology, Copenhagen University Hospital, Bispebjerg, Copenhagen NV Vejle, Denmark.
| | | | | | | | | |
Collapse
|
24
|
Abstract
PURPOSE OF REVIEW To understand the basis for current recommendations for vitamin D supplementation in childhood and the differences between the recommendations published by major expert committees, using the Medline engine of the US National Library of Medicine and the National Institutes of Health. RECENT FINDINGS Recent recommendations published by major national expert committees are essentially based on expert opinion (a relatively low level of evidence). Randomized controlled trials are very few, and there are no systematic reviews or meta-analyses on the topic. Most trials have examined the question of whether a specific daily vitamin D dose is capable or not to prevent rickets (by studying surrogate markers of rickets). There are no trials that have systematically attempted to determine the upper limit of daily vitamin D dose beyond which its toxic effects may appear. Whether or not outcomes such as osteoporosis (or low bone mass) and specific types of cancer may be prevented by 'generous' vitamin D supplementation is unclear and mostly based on indirect epidemiologic data not clearly substantiated by randomized controlled trials SUMMARY The dose of daily vitamin D supplements needed to prevent rickets is probably much lower than that recommended by most expert committees. Whether higher doses of daily vitamin D supplements may or may not prevent other poor outcomes such as adult osteoporosis or specific types of cancer is not yet known.
Collapse
Affiliation(s)
- Francis B Mimouni
- Department of Pediatrics, Shaare Zedek Medical Center, Jerusalem, Israel.
| | | |
Collapse
|
25
|
Abstract
Africa is heterogeneous in latitude, geography, climate, food availability, religious and cultural practices, and skin pigmentation. It is expected, therefore, that prevalence of vitamin D deficiency varies widely, in line with influences on skin exposure to UVB sunshine. Furthermore, low calcium intakes and heavy burden of infectious disease common in many countries may increase vitamin D utilization and turnover. Studies of plasma 25OHD concentration indicate a spectrum from clinical deficiency to values at the high end of the physiological range; however, data are limited. Representative studies of status in different countries, using comparable analytical techniques, and of relationships between vitamin D status and risk of infectious and chronic diseases relevant to the African context are needed. Public health measures to secure vitamin D adequacy cannot encompass the whole continent and need to be developed locally.
Collapse
|
26
|
Reis JP, Michos ED, von Mühlen D, Miller ER. Differences in vitamin D status as a possible contributor to the racial disparity in peripheral arterial disease. Am J Clin Nutr 2008; 88:1469-77. [PMID: 19064505 DOI: 10.3945/ajcn.2008.26447] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Racial differences in cardiovascular risk factors do not fully explain the higher prevalence of lower-extremity peripheral arterial disease (PAD) in black adults. OBJECTIVE We sought to determine whether any of this excess risk may be explained by vitamin D status, which has been widely documented to be lower in blacks than in whites. DESIGN This population-based cross-sectional study included 2987 white and 866 black persons aged >or=40 y from the 2001-2004 National Health and Nutrition Examination Survey. PAD was defined as an ankle-brachial pressure index of <0.90 in either leg. RESULTS Mean (+/-SEM) 25-hydroxyvitamin D [25(OH)D] concentrations were significantly lower in black than in white adults (39.2 +/- 1.0 and 63.7 +/- 1.1 nmol/L, respectively; P < 0.001). Adjusted odds ratios for PAD decreased in a dose-dependent fashion with increasing quartiles of 25(OH)D in white adults [1.00 (referent), 0.86, 0.67, and 0.53; P for trend < 0.001]. In black adults, the association was nonlinear; models with cubic splines suggested evidence of greater odds for PAD and a trend for lower odds for PAD at the lowest and highest concentrations of 25(OH)D, respectively. After adjustment for racial differences in socioeconomic status and for traditional and novel risk factors, odds for PAD in black compared with white adults were reduced from 2.11 (95% CI: 1.55, 2.87) to 1.67 (1.11, 2.51). After additional adjustment for 25(OH)D, the odds were further reduced to 1.33 (0.84, 2.10). CONCLUSIONS Racial differences in vitamin D status may explain nearly one-third of the excess risk of PAD in black compared with white adults. Additional research is needed to confirm these findings.
Collapse
Affiliation(s)
- Jared P Reis
- Welch Center for Prevention, Epidemiology, and Clinical Research and the Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21287, USA.
| | | | | | | |
Collapse
|
27
|
Abstract
There are many mechanisms by which melanocytes, keratinocytes, and Langerhans cells interact within the epidermis. Inflammatory mediators affect melanocyte function and melanogenic agents such as alpha-MSH alter the functions of keratinocytes and Langerhans cells. The epidermal melanin unit is better labeled the KLM unit.
Collapse
|
28
|
|
29
|
Young AR, Walker SL. UV radiation, vitamin D and human health: an unfolding controversy introduction. Photochem Photobiol 2006; 81:1243-5. [PMID: 16354109 DOI: 10.1562/2005-10-16-ra-716] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Antony R Young
- St. John's Institute of Dermatology, Division of Genetics and Molecular Medicine, King's College London School of Medicine at Guy's, St. Thomas' Hospitals, London, England.
| | | |
Collapse
|
30
|
Abstract
Vitamin D insufficiency is more prevalent among African Americans (blacks) than other Americans and, in North America, most young, healthy blacks do not achieve optimal 25-hydroxyvitamin D [25(OH)D] concentrations at any time of year. This is primarily due to the fact that pigmentation reduces vitamin D production in the skin. Also, from about puberty and onward, median vitamin D intakes of American blacks are below recommended intakes in every age group, with or without the inclusion of vitamin D from supplements. Despite their low 25(OH)D levels, blacks have lower rates of osteoporotic fractures. This may result in part from bone-protective adaptations that include an intestinal resistance to the actions of 1,25(OH)2D and a skeletal resistance to the actions of parathyroid hormone (PTH). However, these mechanisms may not fully mitigate the harmful skeletal effects of low 25(OH)D and elevated PTH in blacks, at least among older individuals. Furthermore, it is becoming increasingly apparent that vitamin D protects against other chronic conditions, including cardiovascular disease, diabetes, and some cancers, all of which are as prevalent or more prevalent among blacks than whites. Clinicians and educators should be encouraged to promote improved vitamin D status among blacks (and others) because of the low risk and low cost of vitamin D supplementation and its potentially broad health benefits.
Collapse
Affiliation(s)
- Susan S Harris
- Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111-1524, USA.
| |
Collapse
|
31
|
Harkness LS, Cromer BA. Vitamin D deficiency in adolescent females. J Adolesc Health 2005; 37:75. [PMID: 15963911 DOI: 10.1016/j.jadohealth.2004.07.015] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2003] [Revised: 07/21/2004] [Accepted: 07/21/2004] [Indexed: 11/30/2022]
Abstract
PURPOSE The purpose of this study was to estimate the incidence of low serum 25-hydroxyvitamin D [25(OH)D] levels in adolescent girls and across racial groups and seasons. METHODS Healthy postmenarcheal girls (12-18 years of age) were recruited for the study. Serum samples were assayed for 25(OH)D with a competitive protein binding assay (CPB) (Nichols Institute, San Clemente, California). RESULTS The study included 370 girls (mean age, 15.5 +/- 1.6 y), with a mean serum 25(OH)D level of 53.7(29.0) nmol/L. Seventeen percent of the girls were found to be vitamin D deficient (serum 25(OH)D <or= 27.5 nmol/L) and 54% were vitamin D insufficient (serum 25(OH)D <or= 50 nmol/L) using the CPB assay. There was a significant difference in mean serum 25(OH)D levels between the African-American girls (43.0 nmol/L) and non-African-American girls (72.2 nmol/L) (p < .0001). Mean vitamin D levels were higher in the spring/summer months (60.2 nmol/L) compared with those obtained during the fall/winter months (52.8 nmol/L) (p < .01), and weight was correlated negatively with vitamin D levels (r = -.19) (p = .0002). CONCLUSIONS For adolescent girls living in the northeastern United States, especially African-American girls, low 25(OH)D levels are a noteworthy concern because bone acquisition is crucial during this period of development.
Collapse
Affiliation(s)
- Laura S Harkness
- Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA.
| | | |
Collapse
|
32
|
Dawson-Hughes B. Racial/ethnic considerations in making recommendations for vitamin D for adult and elderly men and women. Am J Clin Nutr 2004; 80:1763S-6S. [PMID: 15585802 DOI: 10.1093/ajcn/80.6.1763s] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Vitamin D is acquired through diet and skin exposure to ultraviolet B light. Skin production is determined by length of exposure, latitude, season, and degree of skin pigmentation. Blacks produce less vitamin D3 than do whites in response to usual levels of sun exposure and have lower 25-hydroxyvitamin D [25(OH)D] concentrations in winter and summer. Blacks in the United States also use dietary supplements less frequently than do whites. However, blacks and whites appear to have similar capacities to absorb vitamin D and to produce vitamin D after repeated high doses of ultraviolet B light. There is a growing consensus that serum 25(OH)D concentrations of at least 75-80 nmol/L are needed for optimal bone health, on the basis of studies of older white subjects living in Europe and the United States. The studies show that increasing serum 25(OH)D concentrations to this level decreases parathyroid hormone (PTH) concentrations, decreases rates of bone loss, and reduces rates of fractures. Among US blacks, low 25(OH)D concentrations are associated with higher concentrations of PTH, which are associated with lower bone mineral density. Vitamin D supplements decrease PTH and bone turnover marker concentrations among blacks. These findings suggest that improving vitamin D status would benefit blacks as well as whites. On the basis of studies conducted in the temperate zone, the intake of vitamin D3 needed to maintain a group average 25(OH)D concentration of 80 nmol/L in winter is approximately 1000 IU/d. Broad-based vitamin D supplementation is needed to remove vitamin D insufficiency as a contributing cause of osteoporosis.
Collapse
Affiliation(s)
- Bess Dawson-Hughes
- Bone Metabolism Laboratory, Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA.
| |
Collapse
|
33
|
Simoons FJ. Persistence of lactase activity among Northern Europeans: A weighing of evidence for the calcium absorption hypothesis. Ecol Food Nutr 2001. [DOI: 10.1080/03670244.2001.9991661] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|
34
|
Koonsvitsky BP, Berry DA, Jones MB, Lin PY, Cooper DA, Jones DY, Jackson JE. Olestra Affects Serum Concentrations of α-Tocopherol and Carotenoids but not Vitamin D or Vitamin K Status in Free-Living Subjects. J Nutr 1997. [DOI: 10.1093/jn/127.8.1636s] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Burton P. Koonsvitsky
- The Department of Family Medicine, Indiana University School of Medicine, Indianapolis, IN 46256
| | - Delia A. Berry
- The Department of Family Medicine, Indiana University School of Medicine, Indianapolis, IN 46256
| | - Michaelle B. Jones
- The Department of Family Medicine, Indiana University School of Medicine, Indianapolis, IN 46256
| | - Peter Y. T. Lin
- The Department of Family Medicine, Indiana University School of Medicine, Indianapolis, IN 46256
| | - Dale A. Cooper
- The Department of Family Medicine, Indiana University School of Medicine, Indianapolis, IN 46256
| | - D. Yvonne Jones
- The Department of Family Medicine, Indiana University School of Medicine, Indianapolis, IN 46256
| | | |
Collapse
|
35
|
|