Serum 25-hydroxyvitamin D and bone mineral density among Hispanic men

Vitamin D deficiency and insufficiency among US adults: prevalence, predictors and clinical implications

Vitamin D deficiency (VDD) and insufficiency (VDI) are increasing at a global level, and they are associated with increased risk of various diseases. However, little information is available on the prevalence and predictors of VDD and VDI in a representative population of US adults. Serum 25-hydroxyvitamin D (25(OH)D) measurements were collected from 26 010 adults aged ≥18 years from the National Health and Nutrition Examination Survey (NHANES) 2001-2010. Using thresholds recommended by the Endocrine Society, VDD was defined as 25(OH)D<50 nmol/l and VDI as 50≤25(OH)D<75 nmol/l. Weighted multinomial log-binomial regression was conducted to estimate prevalence ratios of VDD and VDI. The prevalences of VDD and VDI in 2001-2010 were 28·9 and 41·4 %, respectively. Adults who were black, less educated, poor, obese, current smokers, physically inactive and infrequent milk consumers had a higher prevalence of VDD. After adjustment for other potential predictors, obese adults showed 3·09 times higher prevalence of VDD and 1·80 times higher prevalence of VDI than non-obese adults. Physically inactive adults had 2·00 and 1·36 times higher prevalence of VDD and VDI than active peers. Compared with frequent consumers, rare consumers of milk had 2·44 and 1·25 times higher prevalence of VDD and VDI, respectively. Current alcohol drinkers had 38 % lower prevalence of VDD than non-drinkers. Awareness of the high prevalence of VDD and VDI among US adults and related predictors could inform behavioural and dietary strategies for preventing VDD and monitoring VDI, especially in old, black, obese and inactive individuals who report rare consumption of milk.

Higher Dairy Intakes Are Associated with Higher Bone Mineral Density among Adults with Sufficient Vitamin D Status: Results from the Boston Puerto Rican Osteoporosis Study

Background

Dairy foods have been shown to improve bone mineral density (BMD) in non-Hispanic whites. Puerto Rican adults have a higher prevalence of osteoporosis and vitamin D deficiency than non-Hispanic whites. However, there is little understanding of lifestyle influences on bone in this population.

Objective

The aim of this study was to examine associations of dairy intakes with BMD among adults from the Boston Puerto Rican Osteoporosis Study with and without adequate serum vitamin D status.

Methods

A total of 904 participants in this cross-sectional analysis provided dietary intakes with a culturally tailored food-frequency questionnaire. Dairy food groups were calculated [total dairy, modified dairy (without cream or dairy desserts), fluid dairy (milk + yogurt), cheese, yogurt, and cream and desserts]. BMD (grams per centimeter squared) was measured using dual-energy X-ray absorptiometry. Vitamin D status was defined as sufficient (serum 25-hydroxyvitamin D [25(OH)D] ≥20 ng/mL) or insufficient (<20 ng/mL). General linear models were used to examine associations between dairy intake and BMD, stratified by vitamin D status.

Results

Of the total sample, 73% were women, of whom 87% were postmenopausal. Mean ± SD age was 60.0 ± 7.6 y and mean ± SD body mass index (kg/m2) was 32.3 ± 6.6. Mean serum 25(OH)D (range: 4-48 ng/mL) was 14.3 ± 3.6 ng/mL in insufficient individuals and 26.0 ± 5.5 ng/mL in sufficient individuals. In the full sample, higher intakes of modified dairy foods (β = 0.0015, P = 0.02) and milk (β = 0.0018, P = 0.04) were associated with higher femoral neck (FN) BMD. Among those who were vitamin D sufficient, higher intakes of total dairy (P = 0.03-0.07), fluid dairy (P = 0.01-0.05), and milk (P = 0.02-0.09) were significantly related to higher FN and lumbar spine BMD, respectively. Among vitamin D-insufficient participants, dairy intakes were not associated with BMD (P-range = 0.11-0.94).

Conclusions

Dairy food intakes were associated with higher BMD among adults, particularly those with sufficient vitamin D status. Future studies should confirm findings longitudinally and assess culturally acceptable lifestyle interventions to improve bone health among Hispanic adults. This trial was registered at clinicaltrials.gov as NCT01231958.

Genetic admixture and body composition in Puerto Rican adults from the Boston Puerto Rican Osteoporosis Study

Population admixture plays a role in the risk of chronic conditions that are related to body composition; however, our understanding of these associations in Puerto Ricans, a population characterized by multiple ancestries, is limited. This study investigated the relationship between genetic admixture and body composition in 652 Puerto Ricans from the Boston Puerto Rican Osteoporosis Study. Genetic ancestry was estimated from 100 ancestry-informative markers. Body composition measures were obtained from dual-energy X-ray absorptiometry. Multivariable linear regression analyses examined associations between bone mineral density (BMD) of the hip and lumbar spine and percent fat mass and lean mass with genetic admixture. In Puerto Ricans living on the US mainland, European ancestry was associated with lower BMD at the trochanter (P = 0.039) and femoral neck (P = 0.01), and Native American ancestry was associated with lower BMD of the trochanter (P = 0.04). African ancestry was associated with a higher BMD at the trochanter (P = 0.004) and femoral neck (P = 0.001). Ancestry was not associated with percent fat mass or lean mass or waist circumference. Our findings are consistent with existing research demonstrating inverse associations between European and Native American ancestries and BMD and positive relationships between African ancestry and BMD. This work contributes to our understanding of the high prevalence of chronic disease experienced by this population and has implications for other ethnic minority groups, particularly those with multiple ancestries. Future research should consider interactions between ancestry and environmental factors, as this may provide individualized approaches for disease prevention.

Low vitamin D status strongly associated with periodontitis in Puerto Rican adults

Background

Periodontitis and vitamin D deficiency are both highly prevalent in Puerto Rico. The aim of this pilot study was to evaluate the association between vitamin D levels and periodontal disease in Puerto Rican adults.

Methods

A sex-, age-, and BMI-matched case-control, cross-sectional study was conducted on 24 cases of moderate/severe periodontitis and 24 periodontally healthy controls aged 35 to 64 years. Each participant completed a socio-demographic questionnaire, underwent a full-mouth periodontal examination and provided blood sample to measure serum 25-hydroxyvitamin D (25 (OH) D) levels to assess vitamin D status.

Results

A total of 19 matched case-control pairs (28 females, 10 males) completed the study. Mean serum 25 (OH) D levels were significantly lower in cases (18.5 ± 4.6 ng/ml) than in controls (24.2 ± 7.1 ng/ml; p = 0.006). Lower odds of periodontal disease were observed per unit of 25 (OH) D level (OR 0.885; 95 % CI 0.785, 0.997; p < 0.05).

Conclusions

Lower serum vitamin D levels are significantly associated with periodontitis in Puerto Rican adults.

Inverse Association between Vitamin D Status and Diabetes in a Clinic Based Sample of Hispanic Adults in Puerto Rico

BACKGROUND

Vitamin D deficiency is a public health problem around the world. Diabetes has been associated with vitamin D deficiency. We aimed to examine the association between the vitamin D status and diabetes in a clinic based sample of Hispanic adults in Puerto Rico.

METHODS

Demographics and laboratory test results for serum 25(OH)D, Fasting Blood Glucose (FBG), and Haemoglobin A1C (HbAlc) were extracted from medical records. Vitamin D status was classified as deficient (<12 ng/ml); inadequate (12-20 ng/ml); insufficient (21-29 ng/ml) and optimal (≥30 ng/ml) using serum 25(OH)D levels.

RESULTS

A total of 716 records were included in the analyses. Most were females (63.3%), with mean age of 54.1±14.9 y, mean BMI 30.1±6.3 kg/m2 and mean serum 25(OH)D levels of 24.3±8.6 ng/ml. Most were classified as diabetics (41.1%). Those with diabetes had lower 25(OH)D levels compared to pre-diabetic and normal glucose status (p<0.05). Serum 25(OH) D levels were inversely correlated to FBG and HbA1c in the total sample and in men (p<0.05). After adjusting for age, gender, BMI and seasonality, there was a greater risk of diabetes, but not prediabetes, in those with serum 25(OH)D levels <30 ng/ml. This risk increased from 1.8 times in those with vitamin D insufficiency to 4.2 times in those with vitamin D deficiency (<12 ng/ml).

CONCLUSION

Diabetes risk significantly increased as serum 25(OH)D levels decreased in this group of Hispanic adults, underscoring the importance of routinely screening high risk individuals for vitamin D deficiency and offer supplementation to normalize serum levels.

[Determination of 25(OH)D serum levels in children with systemic lupus erythematosus and juvenile idiopathic arthritis]

BACKGROUND

It is well recognized that vitamin D has a direct effect in bone and muscle and has been associated as well with some rheumatologic diseases. Reports in children are scarce. The aim of this study was to determine the concentration level of 25(OH)D in a group of patients with systemic lupus erythematosus (SLE) and juvenile idiopathic arthritis (JIA) and compare them with healthy controls.

METHODS

Vitamin D (25(OH)D) was measured with isotope-dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS), PTH with immunoradiometric assay (IRMA), calcium, phosphorus and alkaline phosphatase by colorimetric assay in 37 patients with SLE, 37 patients with JIA and 79 healthy controls.

RESULTS

Mean 25(OH)D concentration levels were as follows: SLE 18.9±7.92ng/ml, JIA 21.97±5.55ng/ml and 23.6±3.07ng/ml in healthy controls. There was a significant difference between SLE patients vs. healthy controls (p <0.05); 29.7% of SLE patients, 35.1% of JIA patients and 31.6% of healthy controls had deficient levels of vitamin D.

CONCLUSIONS

One third of the total sample of children in this study had deficient levels of vitamin D. Patients with SLE presented a significant difference compared with healthy controls.

Active vitamin D (1,25-dihydroxyvitamin D) and bone health in middle-aged and elderly men: the European Male Aging Study (EMAS)

CONTEXT

There is little information on the potential impact of serum 1,25-dihydroxyvitamin D [1,25(OH)2D] on bone health including turnover.

OBJECTIVE

The objective of the study was to determine the influence of 1,25(OH)2D and 25-hydroxyvitamin D [25(OH)D] on bone health in middle-aged and older European men.

DESIGN, SETTING, AND PARTICIPANTS

Men aged 40-79 years were recruited from population registers in 8 European centers. Subjects completed questionnaires that included questions concerning lifestyle and were invited to attend for quantitative ultrasound (QUS) of the heel, assessment of height and weight, and a fasting blood sample from which 1,25(OH)2D, 25(OH)D, and PTH were measured. 1,25(OH)2D was measured using liquid chromatography tandem mass spectrometry. Bone markers serum N-terminal propeptide of type 1 procollagen (P1NP) and crosslinks (β-cTX) were also measured. Dual-energy x-ray absorptiometry (DXA) of the hip and lumbar spine was performed in 2 centers.

MAIN OUTCOME MEASURE(S)

QUS of the heel, bone markers P1NP and β-cTX, and DXA of the hip and lumbar spine were measured.

RESULTS

A total of 2783 men, mean age 60.0 years (SD 11.0) were included in the analysis. After adjustment for age and center, 1,25(OH)2D was positively associated with 25(OH)D but not with PTH. 25(OH)D was negatively associated with PTH. After adjustment for age, center, height, weight, lifestyle factors, and season, 1,25(OH)2D was associated negatively with QUS and DXA parameters and associated positively with β-cTX. 1,25(OH)2D was not correlated with P1NP. 25(OH)D was positively associated with the QUS and DXA parameters but not related to either bone turnover marker. Subjects with both high 1,25(OH)2D (upper tertile) and low 25(OH)D (lower tertile) had the lowest QUS and DXA parameters and the highest β-cTX levels.

CONCLUSIONS

Serum 1,25(OH)2D is associated with higher bone turnover and poorer bone health despite being positively related to 25(OH)D. A combination of high 1,25(OH)2D and low 25(OH)D is associated with the poorest bone health.

Prevalence and seasonal variation of hypovitaminosis D and its relationship to bone metabolism in healthy Hungarian men over 50 years of age: the HunMen Study

This study reports a high prevalence of hypovitaminosis D and low bone mineral density (BMD) in a healthy Hungarian male cohort over 50 years of age. Men with 25-hydroxyvitamin D levels of <75 nmol/L had a significantly higher 10-year hip and major osteoporotic fracture probability using the country-specific fracture risk assessment (FRAX) algorithm.

INTRODUCTION

The aim of this study is to characterize the prevalence and seasonal variation of hypovitaminosis D and its relationship to bone metabolism in healthy Hungarian men over 50 years of age.

METHODS

We determined levels of 25-hydroxyvitamin D (25-OH-D), PTH, osteocalcin (OC), C-terminal telopeptides of type-I collagen (CTX-I), procollagen type 1 amino-terminal propeptide (PINP), BMD at L1-L4 (LS) and femur neck (FN), daily dietary calcium intake, and the 10-year probability of hip fracture and a major osteoporotic fracture using the country-specific FRAX algorithm in 206 randomly selected ambulatory men.

RESULTS

The mean (range) age of the volunteers was 60 (51-81) years. The prevalence of hypovitaminosis D (25-OH-D, <75 nmol/L) was 52.9%. The prevalence of low (T-score < -1.0) BMD at the FN and LS was 45% and 35.4%, respectively. The mean (range) FRAX hip fracture and FRAX major osteoporotic fracture was 0.8% (0-9.4%) and 3.8% (1.7-16%), respectively. On comparing the vitamin D sufficient to the insufficient group, there was a statistically significant difference between the FRAX hip fracture and FRAX major osteoporotic fracture indexes. There was significant seasonal variation in the vitamin D levels; the lowest levels were measured in winter and the highest in summer.

CONCLUSIONS

A high prevalence of hypovitaminosis D and low BMD were observed in the studied Hungarian male population. This is the first study reporting higher 10-year hip and major osteoporotic fracture probability using the country-specific FRAX algorithm in individuals with hypovitaminosis D.

Association between vitamin D levels and blood pressure in a group of Puerto Ricans

OBJECTIVE

Hypertension is a global public health problem. The apparent association between vitamin D (VitD) and blood pressure (BP) has been studied in several populations but not in a Puerto Rican population. Therefore, we determined the association between serum 25(OH)D levels and BP in a convenience sample in Puerto Rico.

METHODS

A cross-sectional study of patients attending a local laboratory with an order for serum 25(OH)D levels was performed. Participants completed a questionnaire that solicited the following information: age, sex, weight, height, VitD intake, and history of both sun exposure and hypertension. BP was measured by a phlebotomist on-site and classified according to the Joint National Committee; serum 25(OH)D levels were taken from the record, and VitD status was classified as either optimal (25(OH)D > or = 30 ng/dl) or non-optimal (< 30 ng/dl). Mean, standard deviation, and percentiles were used for descriptive analysis. VitD status and BP were compared by gender, age, and body mass index (BMI) using ANOVA or chi-square. The association between VitD status and blood pressure was assessed by polytomous logistic regression adjusting for several variables.

RESULTS

Two hundred nineteen individuals were included in the analysis; most were females aged 21 to 50 years who were overweight/obese; 53% of the total population was pre-hypertensive or hypertensive; 60% had non-optimal VitD status; and the sun exposure index was 19.6. No significant associations were found between VitD status and blood pressure after adjusting for age, sex, BMI, total VitD intake, and solar exposure index.

CONCLUSION

VitD status was not found to be associated with blood pressure in this sample population; more studies with a larger sample population are needed to determine whether such an association does in fact exist.

Determinants of vitamin D status among overweight and obese Puerto Rican adults

BACKGROUND/AIMS

Low vitamin D status is highly prevalent worldwide, and the major determinants are sun exposure and vitamin D intake. We aimed to measure vitamin D status in a sample of overweight/obese adults in Puerto Rico, an area with plenty of sun exposure, and relate it to vitamin D intake, sun exposure and body composition.

METHODS

Serum 25(OH)D levels (liquid chromatography-tandem mass spectrometry), body weight and fat (bioimpedance), vitamin D intake and sun exposure (questionnaires) were assessed. Analysis included age-adjusted correlations and multivariate regression.

RESULTS

In 98 subjects (66% females; 40-65 years), median serum 25(OH)D levels were 30.7 ng/ml (25-75th percentile 25.0-37.3); 55% had levels >30 ng/ml, 31% had levels between 20 and 30 ng/ml and 14% had levels <20 ng/ml. Total vitamin D intake was 180 IU/day (45-615), and the sun exposure score was 22 (17-27). After adjusting for gender, 25(OH)D levels were significantly correlated with vitamin D intake (r = 0.24, p = 0.018), the sum of sun exposure and vitamin D intake indices (r = 0.34, p = 0.001) and percent body fat (r = -0.25, p = 0.01). After adjusting for age, gender and percent body fat, the sum of sun exposure and vitamin D intake indices remained statistically associated with 25(OH)D levels (β = 1.5, p < 0.01).

CONCLUSIONS

In this group of overweight and obese individuals, 25(OH)D was significantly related to vitamin D intake, sun exposure and vitamin D intake indices and percent body fat.

Hypocalcemia in the critically ill patient

Hypocalcemia is common in the critically ill patient. In this population, however, the diagnosis of hypocalcemia is complicated by limitations in the interpretation of the total plasma calcium concentration. These limitations are principally the result of the effects of hypoalbuminemia and disorders of acid-base balance on the total calcium concentration. Thus, measurement of ionized calcium can be critical in determining an individual's true serum calcium status. In this review, we first describe the regulation of normal calcium metabolism and then focus on the various etiologies of hypocalcemia, including congenital and acquired disorders of parathyroid hormone and vitamin D, which are encountered in the neonatal, pediatric, and adult critical care settings. The approach to the treatment of hypocalcemia and the current consensus on treatment of hypocalcemia in the critically ill patient is also presented.

The biology and pathology of vitamin D control in bone

Vitamin D is a steroid pro-hormone, whose active metabolite binds the vitamin D receptor (VDR) which, in turn, binds to DNA sequences on target genes as a heterodimer with the retinoid-X receptor, resulting in regulation of gene expression. The vitamin D pro-hormone can be synthesized in the skin, in response to ultraviolet radiation; however, dietary sources have become increasingly important as a result of cultural changes over the past few centuries. Based on its initial discovery as an anti-rachitic factor, studies of the role of vitamin D and its receptor have largely focused on the skeleton. Investigations into the pathophysiologic basis and therapeutic responses of skeletal disorders associated with impaired vitamin D action have led to the identification of the molecular pathways involved in hormone activation and regulation of gene expression by the liganded VDR. These studies have also demonstrated that the skeletal actions of the VDR and its ligand are largely redundant if normal mineral ion homeostasis can be maintained by other means. However, investigations in animal models with tissue-specific ablation of the VDR or the enzyme required for hormone activation have demonstrated novel actions in skeletal tissues. The active vitamin D metabolite has been shown to have both paracrine and endocrine actions in other tissues as well.

Prevalence and correlates of vitamin D deficiency in US adults

Mounting evidence suggests that vitamin D deficiency could be linked to several chronic diseases, including cardiovascular disease and cancer. The purpose of this study was to examine the prevalence of vitamin D deficiency and its correlates to test the hypothesis that vitamin D deficiency was common in the US population, especially in certain minority groups. The National Health and Nutrition Examination Survey 2005 to 2006 data were analyzed for vitamin D levels in adult participants (N = 4495). Vitamin D deficiency was defined as a serum 25-hydroxyvitamin D concentrations ≤20 ng/mL (50 nmol/L). The overall prevalence rate of vitamin D deficiency was 41.6%, with the highest rate seen in blacks (82.1%), followed by Hispanics (69.2%). Vitamin D deficiency was significantly more common among those who had no college education, were obese, with a poor health status, hypertension, low high-density lipoprotein cholesterol level, or not consuming milk daily (all P < .001). Multivariate analyses showed that being from a non-white race, not college educated, obese, having low high-density lipoprotein cholesterol, poor health, and no daily milk consumption were all significantly, independently associated with vitamin D deficiency (all P < .05). In summary, vitamin D deficiency was common in the US population, especially among blacks and Hispanics. Given that vitamin D deficiency is linked to some of the important risk factors of leading causes of death in the United States, it is important that health professionals are aware of this connection and offer dietary and other intervention strategies to correct vitamin D deficiency, especially in minority groups.