HHS Public Access Author manuscript Author Manuscript
P R Health Sci J. Author manuscript; available in PMC 2015 August 21. Published in final edited form as: P R Health Sci J. 2015 June ; 34(2): 83–88.
Prevalence of vitamin D insufficiency and deficiency among medical residents of the University Hospital in San Juan, Puerto Rico
Author Manuscript
Leticia Hernández Dávila, MD1, Nixzaliz Rodríguez Rivera, MD1, Mariel López Valentin, BS, MS2, Lillian Haddock, MD, MACP, FACE1, Renil Rodríguez Martínez, MD3, Alex González Bossolo, MD3, and Margarita Ramírez Vick, MD1 1University
of Puerto Rico School of Medicine, Internal Medicine Department, Endocrinology Division, University Hospital, San Juan, Puerto Rico. PO Box 365067, San Juan, Puerto Rico 00936-5067
2Puerto
Rico Clinical and Translational Research Consortium, University of Puerto Rico School of Medicine, Medical Sciences Campus, San Juan, Puerto Rico 3University
of Puerto Rico School of Medicine, Internal Medicine Department, University Hospital, San Juan, Puerto Rico
Abstract Author Manuscript
Vitamin D has been attracting increased attention due to higher prevalence of vitamin D insufficiency and deficiency than expected in areas with sufficient sun exposure. Even though sunlight exposure and diet are the main determinants of Vitamin D status, other factors such as: age, race, use of sunscreen, medications, and malabsorptive conditions affect vitamin D levels. Recent studies have found a high prevalence of vitamin D deficiency and insufficiency in different populations. However, there is limited data of the prevalence of vitamin D deficiency and insufficiency in Puerto Rico. To answer that question we evaluated a sample of 51 internal medicine residents from ages 25 to 39 of the University Hospital in San Juan, Puerto Rico by means of a questionnaire about basic socio-demographic characteristics, anthropometric data, and lifestyle characteristics and obtained blood sampling for 25-hydroxyvitamin D levels.
Author Manuscript
The median 25-hydroxyvitamin D level was 21 ng/mL (range, 7–38 ng/mL). Forty-five participants (88.2%) had 25 hydroxyvitamin D concentrations 1.5 mg/dL), chronic liver disease (bilirubin levels >2 mg/dL) and malignancies. A total of 100 residents were invited to participate in this study: residents of Internal Medicine Program (49), residents of internal medicine subspecialties of the University Hospital (47) and four research fellows. The participation rate was 51% (51/100). Data Collection
Author Manuscript
The residents were invited to fill in the study questionnaire and undergo blood sampling for 25-hydroxyvitamin D, and other biochemical parameters. Blood samplings were obtained through the Intensive Cooperative Laboratory of the University Hospital. Previous laboratory results (no more than 6 months) were considered in this study, as well. These procedures took place at the date determined either by the program director or the chief resident of each program. Blood samples for 25OHvitamin D levels were taken mainly during two seasons of the year, spring (March–May) and winter (November–January). Both interventions were done after obtaining oral informed consent to participate in the study. Study procedures were approved by the Institutional Review Board of the University of Puerto Rico, Medical Sciences Campus. Questionnaire Information
Author Manuscript Author Manuscript
The questionnaire included questions about basic socio-demographic characteristics, anthropometric data, physical activity, diet, sun exposure, and working hours. Body mass Index was categorized according to the World Health Organization definition: Normal (18.5 kg/m2–24.9 kg/m2) and Overweight (≥25 kg/m2). Daily dietary intake of calcium and vitamin D were calculated from the data obtained from a food frequency questionnaire (FFQ) containing 24 questions focusing on both calcium and vitamin D-containing foods consumed regularly. This FFQ was developed for the Latin American Vertebral Osteoporosis Study [25] and validated for the Puerto Rican population by Suárez E and Pérez C, 2009. Current vitamin and mineral supplementation open-ended question was included and used for calculation of mean total intake. To assess the frequency of each food there were 8 choices that ranged from ‘3 or more servings per day’ to ‘rarely or never’. Total intakes of vitamin D and calcium were determined by adding calcium and vitamin D content of food items according to the Department of Agriculture National Nutrient Database for Standard Reference, 2011. Physical activity was categorized as: (1) no physical activity, (2) less than 2.5 hours per day, and (3) 2.5 hours or more per day. Sun exposure was expressed as: (1) Low (not between 10:00 am to 4:00 pm), and (2) High exposure (between 10:00 am and 4:00 pm). Working hours were reported by participants in answer to a question asking the number of hours worked per day (1) ≤9 hours per day and (2) >9 hours per day. In order to estimate the percentage of body surface area exposed to the sun, a total body surface area calculator diagram was used (Wallace, 1951, Rules of Nine Chart).
P R Health Sci J. Author manuscript; available in PMC 2015 August 21.
Dávila et al.
Page 4
Biochemical Analysis
Author Manuscript
Serum 25-hydroxyvitamin D levels were determined using liquid chromatography-tandem mass spectrometry at a reference laboratory, Quest Diagnostics-Tampa, Fl. According to the US Institute of Medicine [26], a 25-hydroxyvitamin D level above 20ng/mL can be considered sufficient at least for skeletal health. And, in recent years, several authors have considered a value above 30ng/mL to be optimal for prevention of many extraskeletal conditions. Therefore, in our study, 25-hydroxyvitamin D levels were categorized as: (1) Deficiency (
P R Health Sci J. Author manuscript; available in PMC 2015 August 21. Published in final edited form as: P R Health Sci J. 2015 June ; 34(2): 83–88.
Prevalence of vitamin D insufficiency and deficiency among medical residents of the University Hospital in San Juan, Puerto Rico
Author Manuscript
Leticia Hernández Dávila, MD1, Nixzaliz Rodríguez Rivera, MD1, Mariel López Valentin, BS, MS2, Lillian Haddock, MD, MACP, FACE1, Renil Rodríguez Martínez, MD3, Alex González Bossolo, MD3, and Margarita Ramírez Vick, MD1 1University
of Puerto Rico School of Medicine, Internal Medicine Department, Endocrinology Division, University Hospital, San Juan, Puerto Rico. PO Box 365067, San Juan, Puerto Rico 00936-5067
2Puerto
Rico Clinical and Translational Research Consortium, University of Puerto Rico School of Medicine, Medical Sciences Campus, San Juan, Puerto Rico 3University
of Puerto Rico School of Medicine, Internal Medicine Department, University Hospital, San Juan, Puerto Rico
Abstract Author Manuscript
Vitamin D has been attracting increased attention due to higher prevalence of vitamin D insufficiency and deficiency than expected in areas with sufficient sun exposure. Even though sunlight exposure and diet are the main determinants of Vitamin D status, other factors such as: age, race, use of sunscreen, medications, and malabsorptive conditions affect vitamin D levels. Recent studies have found a high prevalence of vitamin D deficiency and insufficiency in different populations. However, there is limited data of the prevalence of vitamin D deficiency and insufficiency in Puerto Rico. To answer that question we evaluated a sample of 51 internal medicine residents from ages 25 to 39 of the University Hospital in San Juan, Puerto Rico by means of a questionnaire about basic socio-demographic characteristics, anthropometric data, and lifestyle characteristics and obtained blood sampling for 25-hydroxyvitamin D levels.
Author Manuscript
The median 25-hydroxyvitamin D level was 21 ng/mL (range, 7–38 ng/mL). Forty-five participants (88.2%) had 25 hydroxyvitamin D concentrations 1.5 mg/dL), chronic liver disease (bilirubin levels >2 mg/dL) and malignancies. A total of 100 residents were invited to participate in this study: residents of Internal Medicine Program (49), residents of internal medicine subspecialties of the University Hospital (47) and four research fellows. The participation rate was 51% (51/100). Data Collection
Author Manuscript
The residents were invited to fill in the study questionnaire and undergo blood sampling for 25-hydroxyvitamin D, and other biochemical parameters. Blood samplings were obtained through the Intensive Cooperative Laboratory of the University Hospital. Previous laboratory results (no more than 6 months) were considered in this study, as well. These procedures took place at the date determined either by the program director or the chief resident of each program. Blood samples for 25OHvitamin D levels were taken mainly during two seasons of the year, spring (March–May) and winter (November–January). Both interventions were done after obtaining oral informed consent to participate in the study. Study procedures were approved by the Institutional Review Board of the University of Puerto Rico, Medical Sciences Campus. Questionnaire Information
Author Manuscript Author Manuscript
The questionnaire included questions about basic socio-demographic characteristics, anthropometric data, physical activity, diet, sun exposure, and working hours. Body mass Index was categorized according to the World Health Organization definition: Normal (18.5 kg/m2–24.9 kg/m2) and Overweight (≥25 kg/m2). Daily dietary intake of calcium and vitamin D were calculated from the data obtained from a food frequency questionnaire (FFQ) containing 24 questions focusing on both calcium and vitamin D-containing foods consumed regularly. This FFQ was developed for the Latin American Vertebral Osteoporosis Study [25] and validated for the Puerto Rican population by Suárez E and Pérez C, 2009. Current vitamin and mineral supplementation open-ended question was included and used for calculation of mean total intake. To assess the frequency of each food there were 8 choices that ranged from ‘3 or more servings per day’ to ‘rarely or never’. Total intakes of vitamin D and calcium were determined by adding calcium and vitamin D content of food items according to the Department of Agriculture National Nutrient Database for Standard Reference, 2011. Physical activity was categorized as: (1) no physical activity, (2) less than 2.5 hours per day, and (3) 2.5 hours or more per day. Sun exposure was expressed as: (1) Low (not between 10:00 am to 4:00 pm), and (2) High exposure (between 10:00 am and 4:00 pm). Working hours were reported by participants in answer to a question asking the number of hours worked per day (1) ≤9 hours per day and (2) >9 hours per day. In order to estimate the percentage of body surface area exposed to the sun, a total body surface area calculator diagram was used (Wallace, 1951, Rules of Nine Chart).
P R Health Sci J. Author manuscript; available in PMC 2015 August 21.
Dávila et al.
Page 4
Biochemical Analysis
Author Manuscript
Serum 25-hydroxyvitamin D levels were determined using liquid chromatography-tandem mass spectrometry at a reference laboratory, Quest Diagnostics-Tampa, Fl. According to the US Institute of Medicine [26], a 25-hydroxyvitamin D level above 20ng/mL can be considered sufficient at least for skeletal health. And, in recent years, several authors have considered a value above 30ng/mL to be optimal for prevention of many extraskeletal conditions. Therefore, in our study, 25-hydroxyvitamin D levels were categorized as: (1) Deficiency (
