Vitamin D insufficiency and hyperparathyroidism in a low income, multiracial, elderly population

A novel SNP in a vitamin D response element of the CYP24A1 promoter reduces protein binding, transactivation, and gene expression

The active form of vitamin D (1alpha,25(OH)(2)D(3)) is known to have antiproliferative effects and has been implicated in cancers of the colon, breast, and prostate. These cancers occur more frequently among African Americans than Caucasians, and individuals with African ancestry are known to have approximately twofold lower levels of serum vitamin D (25(OH)D) compared with individuals of European ancestry. However, epidemiological studies of the vitamin D receptor (VDR) have shown inconsistent associations with cancer risk, suggesting that differences in other genes in the pathway may be important. We sought to identify functionally significant polymorphic variants in CYP24A1, a gene that is highly inducible by 1alpha,25(OH)(2)D(3) and that encodes the primary catabolic enzyme in the pathway. Here we report the identification of six novel SNPs in the human CYP24A1 promoter, including one at nucleotide -279 occurring within the distal vitamin D response element (VDRE2). Our experiments demonstrate that the VDRE2 variant results in decreased protein binding and transactivation in vitro, and reduced expression of CYP24A1 in cultured primary human lymphocytes provides evidence for an effect in vivo. This variant was only observed in our African American population, and represents a first step toward understanding differences in disease risk among racial/ethnic groups.

Clinical challenges in the management of osteoporosis

While knowledge regarding the diagnosis and treatment of osteoporosis has expanded dramatically over the last few years, gaps in knowledge still exist with guidance lacking on the appropriate management of several common clinical scenarios. This article uses fictional clinical scenarios to help answer three challenging questions commonly encountered in clinical practice. The first clinical challenge is when to initiate drug therapy in a patient with low bone density. It is estimated that 34 million America have low bone density and are at a higher risk for low trauma fractures. Limitations of using bone mineral density alone for drug therapy decisions, absolute risk assessment and evidence for the cost-effectiveness of therapy in this population are presented. The second clinical challenge is the prevention and treatment of vitamin D deficiency. Appropriate definitions for vitamin D insufficiency and deficiency, the populations at risk for low vitamin, potential consequences of low vitamin D, and how to manage a patient with low vitamin D are reviewed. The third clinical challenge is how to manage a patient receiving drug therapy for osteoporosis who has been deemed a potential treatment failure. How to define treatment failure, common causes of treatment failure, and the approach to the management of a patient who is not responding to appropriate osteoporosis therapy are discussed.

Screening for chronic kidney disease complications in US adults: racial implications of a single GFR threshold

BACKGROUND AND OBJECTIVES

An ideal and effective screening tool should perform equally across ethnic groups. The objective of this study was to determine whether the widely advocated creatinine-based estimated GFR (eGFR) threshold of 60 ml/min per 1.73 m(2) identifies the typical metabolic abnormalities related to chronic kidney disease equally well in minority and nonminority adults.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This objective was addressed using data for 8918 minority and nonminority adult participants in the National Health and Nutrition Examination Survey 2003 through 2006, which used stratified, multistage, probability sampling methods to assemble a nationwide probability sample of the noninstitutionalized population of the United States. Metabolic abnormalities including BP, potassium, hemoglobin, bicarbonate, uric acid, calcium, phosphorus, and parathyroid hormone were defined by fifth or 95th percentile values.

RESULTS

Among participants with eGFR <60 ml/min per 1.73 m(2), black individuals were more likely than white individuals to have low hemoglobin (adjusted odds ratio [aOR] 3.76; 95% confidence interval [CI] 1.94 to 7.28), elevated uric acid (aOR 2.15; 95% CI 1.26 to 3.68), and elevated parathyroid hormone (aOR 3.93; 95% CI 2.33 to 6.66).

CONCLUSIONS

Metabolic consequences of reduced eGFR are more common in black individuals and seem to be present at levels well above 60 ml/min per 1.73 m(2); thus, black individuals should be screened for the metabolic complications of chronic kidney at higher GFR levels.

Vitamin D insufficiency: disease or no disease?

Vitamin D insufficiency (VDI) is widely reported. In patients with normal PTH, the diagnosis rests on increases in fractional calcium absorption (FCA) when 25(OH)D increases above 30 ng/ml. However, estimates of increased FCA after correction of VDI vary dramatically, depending on study methods. We used a dual stable calcium isotope to clarify the impact of vitamin D repletion on FCA in postmenopausal women with VDI. We hypothesized that FCA would increase with vitamin D repletion. We studied postmenopausal women with VDI [25(OH)D = 16-24 ng/ml] and an estimated calcium intake <or=1100 mg daily. Exclusion criteria included hypercalcemia, hypercalciuria, renal insufficiency, nephrolithiasis, gastrointestinal disorders, osteomalacia, prior adult fragility fracture, baseline T-score < -3.0, and use of medications known to interfere with vitamin D or calcium metabolism. Each woman underwent inpatient FCA studies before and after correction of VDI. We used ergocalciferol 50,000 IU/d for 15 days to achieve vitamin D repletion. During each study, women consumed their typical diet. They ingested (44)Ca orally with breakfast and received (42)Ca intravenously. We collected urine for 24 h and measured its calcium isotope content by mass spectrometry. Eighteen women completed the study; all but two had normal PTH. During the first and second FCA studies, their mean 25(OH)D level was 22 +/- 4 and 64 +/- 21 ng/ml, respectively (p < 0.001). Subjects' average FCA was 24 +/- 7% initially and 27 +/- 6% after vitamin D repletion (p = 0.04). Thus, FCA increased by 3 +/- 1% with correction of VDI. Postmenopausal women with VDI experience small FCA increments with vitamin D therapy. In existing literature, this small change in FCA does not associate with lower fracture rates or consistently higher bone mass. Future studies should ascertain whether small FCA increments favorably affect the skeleton.

Risk factors for decreased bone density and effects of HIV on bone in the elderly

Most studies of bone density in HIV-infected individuals focus on young men. This study compares differences in bone density in elderly HIV positive men and women to HIV negative controls. Bone density was lower in the lumbar spine and hip in the HIV-infected group. Antiretrovirals may be associated with decreased bone mineralization.

INTRODUCTION

Individuals with human immunodeficiency virus (HIV) may be at increased risk for osteoporosis. Prolonged exposures to HIV and/or antiretroviral therapy are possible causes for this association. This study compares differences in bone mineral density (BMD) in elderly HIV positive men and women to HIV negative controls.

METHODS

A cross-sectional study was conducted among 57 HIV-infected and 47 HIV negative subjects over age 55. BMD at the lumbar spine and total hip and markers of bone turnover were compared.

RESULTS

BMD was borderline lower in the lumbar spine and significantly lower in the hip in the HIV-infected group. Controlling for age, sex, race and body mass index, differences between the groups were significant at both sites. There was no difference in markers of bone turnover between the groups. Tenofovir use was significantly associated with decreased BMD at the spine while protease inhibitor use was significantly associated with decreased BMD at the hip.

CONCLUSION

Elderly men and women with HIV have lower bone mass than HIV negative controls. Decreased body mass index was the most important risk factor associated with decreased BMD. Bone demineralization was observed among HIV-infected subjects receiving either tenofovir or a protease inhibitor.

Impact of activated vitamin D and race on survival among hemodialysis patients

Contrary to most examples of disparities in health outcomes, black patients have improved survival compared with white patients after initiating hemodialysis. Understanding potential explanations for this observation may have important clinical implications for minorities in general. This study tested the hypothesis that greater use of activated vitamin D therapy accounts for the survival advantage observed in black and Hispanic patients on hemodialysis. In a prospective cohort of non-Hispanic white (n = 5110), Hispanic white (n = 979), and black (n = 3214) incident hemodialysis patients, higher parathyroid hormone levels at baseline were the primary determinant of prescribing activated vitamin D therapy. Median parathyroid hormone was highest among black patients, who were most likely to receive activated vitamin D and at the highest dosage. One-year mortality was lower in black and Hispanic patients compared with white patients (16 and 16 versus 23%; P < 0.01), but there was significant interaction between race and ethnicity, activated vitamin D therapy, and survival. In multivariable analyses of patients treated with activated vitamin D, black patients had 16% lower mortality compared with white patients, but the difference was lost when adjusted for vitamin D dosage. In contrast, untreated black patients had 35% higher mortality compared with untreated white patients, an association that persisted in several sensitivity analyses. In conclusion, therapy with activated vitamin D may be one potential explanation for the racial differences in survival among hemodialysis patients. Further studies should determine whether treatment differences based on biologic differences contribute to disparities in other conditions.

Serum 25-hydroxyvitamin D and bone mineral density in a racially and ethnically diverse group of men

CONTEXT

Although racial and ethnic differences in vitamin D status and bone mineral density (BMD) are recognized, less is known about how differences in vitamin D status impact BMD, especially among men.

OBJECTIVE

Our objective was to examine the relation between serum 25-hydroxyvitamin D [25(OH)D] and BMD by race and ethnic group.

DESIGN

We conducted a population-based, observational survey.

PARTICIPANTS

PARTICIPANTS included 1114 Black, Hispanic, and White men, 30-79 yr of age.

OUTCOMES

We assessed 25(OH)D by a competitive protein binding assay and BMD by dual-energy x-ray absorptiometry.

RESULTS

Mean age +/- SD of the 331 Black, 362 Hispanic, and 421 White men was 48 +/- 12.8 yr. Mean 25(OH)D was lower among Black (25.0 +/- 14.7 ng/ml) and Hispanic (32.9 +/- 13.9 ng/ml) men compared with White men (37.4 +/- 14.0 ng/ml, P < 0.01). A higher percentage of both Black (44%) and Hispanic (23%) men had levels of 25(OH)D in the lowest quartile, compared with 11% of White men (P < 0.001). After adjusting for age, height, and weight, only White men showed significant positive correlation between 25(OH)D and BMD (range of correlations, 0.00-0.14). Serum 25(OH)D was not associated with BMD in Black or Hispanic men at any bone site. Results were similar when adjusted for age only.

CONCLUSIONS

Our findings confirm substantial racial and ethnic group differences in BMD and serum 25(OH)D in men. Serum 25(OH)D and BMD are significantly related to one another in White men only. This may have implications for evaluation of bone health and supplementation in men with low levels of 25(OH)D. Further understanding of the biological mechanisms for these differences between race and ethnic groups is needed.

Dose response to vitamin D supplementation among postmenopausal African American women

BACKGROUND

Reports on the dose response to vitamin D are conflicting, and most data were derived from white men and women.

OBJECTIVE

The objective was to determine the response of serum 25-hydroxyvitamin D [25(OH)D] to oral vitamin D(3) supplementation in an African American population.

DESIGN

Healthy black postmenopausal women (n = 208) participated in a vitamin D(3) supplementation trial for a period of 3 y. Analyses were done in the vitamin D supplementation arm (n = 104) to quantify the response in serum 25-hydroxyvitamin D concentrations at a steady state vitamin D input. The participants received 20 microg/d (800 IU) oral vitamin D(3) for the initial 2 y and 50 microg/d (2000 IU) for the third year.

RESULTS

Supplementation with 20 microg/d (800 IU/d) vitamin D(3) raised the mean serum 25(OH)D concentration from a baseline of 46.9 +/- 20.6 nmol/L to 71.4 +/- 21.5 nmol/L at 3 mo. The mean (+/-SD) concentration of serum 25(OH)D was 87.3 +/- 27.0 nmol/L 3 mo after supplementation increased to 50 microg/d (2000 IU/d). All participants achieved a serum 25(OH)D concentration >35 nmol/L, 95% achieved a concentration >50 nmol/L, but only 60% achieved a concentration >75 nmol/L. All patients had concentrations <153 nmol/L. On the basis of our findings, an algorithm for prescribing vitamin D so that patients reach optimal serum concentrations was developed. The algorithm suggests a dose of 70 microg (2800 IU/d) for those with a concentration >45 nmol/L and a dose of 100 microg (4000 IU/d) for those with a concentration <45 nmol/L.

CONCLUSIONS

Supplementation with 50 microg/d (2000 IU/d) oral vitamin D(3) is sufficient to raise serum 25-hydroxyvitamin D concentrations to >50 nmol/L in almost all postmenopausal African American women. However, higher doses were needed to achieve concentrations >75 nmol/L in many women in this population.

Prevalence of vitamin D deficiency in uninsured women

BACKGROUND

Vitamin D deficiency, an important risk factor for osteoporosis and other chronic medical conditions, is epidemic in the United States. Uninsured women may be at an even higher risk for vitamin D deficiency than others owing to low intake of dietary and supplemental vitamin D and limited sun exposure.

OBJECTIVE

Our goal was to determine the prevalence of vitamin D deficiency in this vulnerable population.

SETTING AND PARTICIPANTS

We enrolled 145 uninsured women at a County Free Medical Clinic in urban Michigan. Questionnaires were used to obtain information about demographics, medical history, vitamin supplementation, sunlight exposure, and dietary vitamin D intake.

RESULTS

The 96 women who were tested for vitamin D status ranged in age from 21 to 65 years (mean 48 +/- 11), and 67% were vitamin D deficient as indicated by a 25-hydroxyvitamin D [25(OH)D)] level <50 nmol/L (20 ng/mL). Non-Caucasians were 3 times more likely than Caucasians to be vitamin D deficient (P = .049). Mean dietary vitamin D intake was low (125 +/- 109 IU/d) and only 24% of the participants used any supplemental vitamin D. Participants with total vitamin D intake <400 IU/day from diet and supplements were 10 times more likely to be vitamin D deficient than others (P < .001).

CONCLUSIONS

These results demonstrate a high prevalence of vitamin D deficiency in an uninsured, medically underserved female population. Uninsured women should be strongly encouraged to increase their vitamin D intake.

Serum 25-hydroxyvitamin D, parathyroid hormone, and bone mineral density in men: the Rancho Bernardo study

INTRODUCTION

This study examined the distribution and determinants of serum 25-hydroxyvitamin D (25OHD) and parathyroid hormone (PTH) and their associations with bone mineral density (BMD) at the hip and spine in 414 older men (mean age 74 years) living in southern California.

METHODS

At a clinic visit (1997-2000), demographic and lifestyle information, fracture history, and medication use were recorded; venous blood for serum 25OHD and PTH was obtained; and BMD was measured at the hip and spine.

RESULTS

Only one man had vitamin D deficiency (25OHD <20 nmol/l), but 15.5% of the men had high parathyroid levels (PTH >or=65 pg/ml). The mean 25OHD and PTH levels were 109.0 nmol/l and 50.3 pg/ml, respectively. Overall, 21.5% used calcium and 9.7% used vitamin D supplements. Serum 25OHD decreased with age and was lowest in the winter; levels were higher in supplement users (vitamin D and/or calcium; p<0.01). Serum PTH did not vary by age or season, and it was lower in supplement users (p<0.01). After excluding 12 men who were outliers for serum 25OHD and PTH, there was no significant correlation between serum 25OHD and PTH (r=-0.05, p=0.3). In multiple adjusted models, serum 25OHD was positively associated with BMD at the hip (p=0.01) and spine (p=0.001). Serum PTH was moderately and inversely associated with BMD at the hip (p=0.04) but not at the spine (p=0.77).

CONCLUSION

We conclude that serum 25OHD is associated with bone health in older, community-dwelling men.

Macro- and micronutrients in African-Americans with heart failure

An emerging body of evidence suggests secondary hyperparathyroidism (SHPT) may be an important covariant of congestive heart failure (CHF), especially in African-Americans (AA) where hypovitaminosis D is prevalent given that melanin, a natural sunscreen, mandates prolonged exposure of skin to sunlight and where a housebound lifestyle imposed by symptomatic CHF limits outdoor activities and hence sunlight exposure. In addition to the role of hypovitaminosis D in contributing to SHPT is the increased urinary and fecal losses of macronutrients Ca(2+) and Mg(2+) associated with the aldosteronism of CHF and their heightened urinary losses with furosemide treatment of CHF. Thus, a precarious Ca(2+) balance seen with reduced serum 25(OH)D is further compromised when AA develop CHF with circulating RAAS activation and are then treated with a loop diuretic. SHPT accounts for a paradoxical Ca(2+) overloading of diverse tissues and the induction of oxidative stress at these sites which spills over to the systemic circulation. In addition to SHPT, hypozincemia and hyposelenemia have been found in AA with compensated and decompensated heart failure and where an insufficiency of these micronutrients may have its origins in inadequate dietary intake, altered rates of absorption or excretion and/or tissue redistribution, and treatment with an ACE inhibitor or AT(1) receptor antagonist. Zn and Se deficiencies, which compromise the activity of several endogenous antioxidant defenses, could prove contributory to the severity of heart failure and its progressive nature. These findings call into question the need for nutriceutical treatment of heart failure and which is complementary to today's pharmaceuticals, especially in AA.

High prevalence of secondary hyperparathyroidism due to hypovitaminosis D in hospitalized elderly with and without hip fracture

OBJECTIVES

To determine and compare the prevalence of secondary hyperparathyroidism (HPTH) in a population of community-dwelling and institutionalized older adults hospitalized with and without hip fracture, and to evaluate factors correlated with secondary HPTH in this population.

METHODS

Circulating concentrations of serum intact PTH, 25-hydroxyvitamin D [25(OH)D] total serum calcium and albumin were measured in 160 subjects with an osteoporotic fracture of the proximal femur and in 160 matched controls hospitalized for a disease unrelated to bone status. Patients with secondary causes of bone loss and taking medications affecting bone metabolism were excluded. Age, sex, place of residence and the ability to perform basic activities of daily living (BADL) two weeks before hospital admission were recorded at baseline.

RESULTS

Patients were comparable with regard to the baseline demographic, biochemical and functional characteristics. The overall prevalence of secondary hyperparathyroidism was 51.2%, without significant differences between hip fractured patients and controls (50.6 vs 51.9%, p=0.911). In bivariate analysis only the age and functional status (BADL) demonstrated a significant relationship with secondary HPTH, while sex and place of residence were not significant. These results were also confirmed in multivariate analysis. Particularly, the risk of secondary HPTH increased with age and with the number of functions lost in BADL: patients fully dependent showed a 3 times as high risk (odd ratio 3.07, 95% confidence interval 1.73 to 5.46, p=0.000) compared to patients independent in BADL, and subject aged >88 yr had a twice as high risk of developing secondary HPTH compared to younger ones (odd ratio 2.28, 95% confidence interval 1.20 to 4.32, p=0.012).

CONCLUSION

These results show that secondary HPTH due to hypovitaminosis D is a frequent disorder in hospitalized elderly, strongly correlated with the functional status, irrespective of sex and place of residence.

Optimal vitamin D status and serum parathyroid hormone concentrations in African American women

BACKGROUND

Optimal vitamin D status for the prevention of osteoporosis has been inferred from examinations of the serum 25-hydroxyvitamin D [25(OH)D] concentration below which there is an increase in serum parathyroid hormone (PTH).

OBJECTIVE

The objectives of the study were to ascertain whether a threshold for serum 25(OH)D exists below which serum PTH increases and whether persons with 25(OH)D above this threshold have lower rates of bone loss than do persons with 25(OH)D below the threshold.

DESIGN

The relation of serum 25(OH)D to serum PTH was analyzed in 208 African American women studied longitudinally for 3 y. These healthy women in midlife were randomly assigned to receive placebo or 800 IU vitamin D3/d; after 2 y, the vitamin D3 supplementation was increased to 2000 IU/d. Both groups received calcium supplements to ensure an adequate calcium intake. A systematic literature review found a wide range of threshold values in part due to varied calcium intake.

RESULTS

A Loess plot suggested a breakpoint between 40 and 50 nmol/L for serum 25(OH)D. A line-line model was fitted to the data, and it showed a spline knot at 44 nmol/L. A heuristic approach verified that PTH does not decline as rapidly when the serum concentration of 25(OH)D is >40 nmol/L as when it is <40 nmol/L. We found no significant difference in rates of bone loss between persons with 25(OH)D concentrations above and below 40 nmol/L.

CONCLUSION

Although a threshold for 25(OH)D can be identified, we suggest that it should not be used to recommend optimal vitamin D status.

Characteristics of elderly patients admitted to an urban tertiary care hospital with osteoporotic fractures: correlations with risk factors, fracture type, gender and ethnicity

Osteoporosis is a major public health problem in the United States of America and around the world, largely due to the morbidity and mortality associated with osteoporotic fractures. In the past decade, large epidemiologic studies have contributed greatly to our understanding of patients who fracture. However, most studies are limited to postmenopausal white women. In this retrospective review, we analyze data from 185 men and women with acute fragility fractures who received osteoporosis consultations during admission to a single urban hospital between 2001 and 2003. Men and women differed in terms of risk factors for falls and osteoporosis but had areal bone mineral density (BMD) measurements remarkably similar, except at the total hip. Black and Hispanic subjects with fractures were significantly younger than whites yet were much more likely to have serious co-morbidities, such as diabetes mellitus and hypertension. In spite of significantly higher BMD measurements, black patients had the highest rates of vitamin D deficiency and secondary hyperparathyroidism. Patients admitted with hip fractures differed from those with non-hip fractures on a number of important variables. Based on these data, we conclude that elderly subjects admitted to an urban hospital with osteoporotic fractures are a heterogeneous group, with features that vary according to fracture type, gender and ethnicity. Future studies of patients with clinical fragility fractures should include ample numbers of men and ethnic minorities, since differences in underlying risk factors may suggest alternative strategies for fracture prevention.

The role of vitamin D in cancer prevention

Vitamin D status differs by latitude and race, with residents of the northeastern United States and individuals with more skin pigmentation being at increased risk of deficiency. A PubMed database search yielded 63 observational studies of vitamin D status in relation to cancer risk, including 30 of colon, 13 of breast, 26 of prostate, and 7 of ovarian cancer, and several that assessed the association of vitamin D receptor genotype with cancer risk. The majority of studies found a protective relationship between sufficient vitamin D status and lower risk of cancer. The evidence suggests that efforts to improve vitamin D status, for example by vitamin D supplementation, could reduce cancer incidence and mortality at low cost, with few or no adverse effects.

Bone mass and mineral metabolism in HIV+ postmenopausal women

The objective of this cross-sectional study was to estimate the prevalence of and risk factors for osteoporosis in HIV+ postmenopausal women. Bone mineral density (BMD) by dual energy X-ray absorptiometry (DXA) and biochemical indices of mineral metabolism were measured in 31 Hispanic and African American HIV+ postmenopausal women. BMD was compared with 186 historical controls, matched for age, ethnicity and postmenopausal status. Mean BMD was significantly lower at the lumbar spine and total hip in the HIV+ group, as compared with controls. Prevalence of osteoporosis was higher in the HIV+ group than controls at the lumbar spine (42% vs 23%, p =0.03) and total hip (10% vs 1%, p =0.003). Among HIV+ women, time since menopause and weight were significant predictors of BMD, while duration or class of antiretroviral therapy (ART), AIDS diagnosis, nadir CD4, steroid use, and vitamin D deficiency were not. Prevalence of osteoporosis is substantially higher in HIV+ Hispanic and African-American postmenopausal women than in controls. Established osteoporosis risk factors were more important in predicting BMD than factors associated with HIV infection and ART. Long-term management of the growing female HIV population should include the evaluation for and management of osteoporosis.

Prevalence of vitamin D insufficiency in postmenopausal south Indian women

AIM

To evaluate the dietary calcium and vitamin D status in south Indian postmenopausal women.

METHODS

Postmenopausal women (n = 164) were evaluated for their daily dietary calcium intake, phytate to calcium ratio, and bone mineral parameters. Their serum leutinizing hormone (LH), follicle-stimulating hormone (FSH), 25-hydroxyvitamin D (25[OH]D), and parathyroid hormone levels (PTH) were measured.

RESULTS

Their age and BMI were 59.5 +/- 8 years and 27 +/- 5 kg/m2, respectively. Their daily dietary intake of calcium was 323 +/- 66 mg/day; phytate to calcium ratio, 0.56+/-0.1; LH, 26 +/- 13.5 microIU/l; and FSH, 62.6 +/- 30 microIU/l. Their dietary intake of calcium was low compared with the recommended daily/dietary allowance (RDA) of the Indian Council of Medical Research (ICMR) for the Indian population. Of the 164 patients studied, based on population-based reference values, 126 (77%) had normal 25(OH)D levels (9-37.6 ng/ml), and 38 (23%) had 25(OH)D deficiency. Using functional health-based reference values, 30 (18%) patients had normal 25(OH)D levels (> 20 ng/ml), 85 (52%) had 25(OH)D insufficiency (10-20 ng/ml), and 49(30%) had 25(OH)D deficiency (< 10 ng/ml). PTH and serum alkaline phosphatase (SAP) was significantly high in patients with 25(OH)D deficiency (p < 0.05) compared with those with normal 25(OH)D levels. There was a negative correlation between 25(OH)D and PTH (r = -0.2; p < 0.007) and SAP (r = -0.2; p < 0.001). Dietary calcium correlated positively with dietary phosphates (r = 0.8; p < 0.001) and phytate to calcium ratio (r = 0.75; p < 0.001).

CONCLUSIONS

Population-based reference values underdiagnosed vitamin D insufficiency and overdiagnosed normal vitamin D status. The diet was insufficient in calcium and high in phytate. About 82% of the study group had varying degrees of low 25-hydroxyvitamin D levels. The quality of diet has to be improved with enrichment/supplementation of calcium and vitamin D to suppress secondary hyperparathyroidism-induced bone loss and risk of fractures.

Hypovitaminosis D, impaired bone turnover and low bone mass are common in patients with peripheral arterial disease

Hypovitaminosis D is common in patients with peripheral arterial disease (PAD). Subsequent secondary hyperparathyroidism and osteomalacia contribute to bone pain and myalgias, and so aggravate clinical symptoms of claudication. We evaluated 95 out of 297 patients with angiographically confirmed PAD stages II (pain in the calves and/or thighs only during exercise) or IV (history of, or presence of local ulcers) and compared them with 44 matched healthy controls regarding their medical history, bone density measurements of the femoral neck and calcaneal bone ultrasound. Bone pain, myalgias and mobility restriction as well as routine laboratory parameters, serum vitamin D [25(OH)D], crosslaps (CTX), parathyroid hormone (PTH), osteocalcin (OC) and alkaline phosphatase (AP) were recorded and analysed. 25(OH)D was significantly lower in PAD IV patients (9.6+/-4.6 ng/ml, P<0.0001) as compared to PAD II stages and controls (19.0+/-7.6 and 19.1+/-9.1 ng/ml), paralleled by lower serum calcium [2.24+/-0.02 mmol/l, P=0.0002 versus PAD II (2.36+/-0.02) and P<0.0001 versus controls (2.39+/-0.02)] and higher iPTH serum levels (66.3+/-3.6 pg/ml, P<0.0001) as compared to PAD II patients (45.3+/-3.5) and healthy controls (38.5+/-2.4). Alkaline phosphatase and serum crosslaps values were significantly higher and age-adjusted bone density and bone ultrasound measurements significantly lower in PAD IV patients, who were also twice as likely to have bone pain and myalgias as PAD II patients. Bone ultrasound measurements correlated significantly with both clinical severity and pain as well as serological parameters of bone metabolism. Underlying PAD has a significant impact on bone density and metabolism as well as on bone and muscular pain. Patients with PAD are at high risk for osteoporosis and osteomalacia and should be regularly monitored and treated for their vitamin D deficiencies.

Management of vitamin d depletion in postmenopausal women

In the United States, the impact regarding the routine fortification of milk and other dairy products has been less than satisfactory in preventing vitamin D depletion in adults. As more individuals are being evaluated and treated for osteoporosis, it has become necessary to exclude vitamin D depletion as a cause, because of the likelihood that differences in vitamin D and calcium nutrition may modify the individual response to therapy. Increased prevalence of subclinical vitamin D depletion among vertebral and hip fracture patients and the beneficial effect of vitamin D therapy and calcium supplementation in preventing such fractures lend credence to this assumption. The prevalence of vitamin D depletion is increasing again, especially among older adults, precisely the group at greatest risk for osteoporotic fractures.

Vitamin D deficiency and secondary hyperparathyroidism are common complications in patients with peripheral arterial disease

OBJECTIVE

To investigate via the vitamin D status whether patients with peripheral arterial disease (PAD) tend to develop vitamin D deficiency that in turn influences their clinical symptoms.

DESIGN

Cross-sectional.

SETTING

University hospital.

PATIENTS AND PARTICIPANTS

Three hundred twenty-seven patients were evaluated; subjects with secondary causes of bone disease or bone active medication were excluded. One hundred sixty-one patients with either PAD stage II (n = 84) or stage IV (n = 77) were enrolled and compared to 45 age- and sex-matched healthy controls.

MEASUREMENTS AND MAIN RESULTS

All patients underwent determinations of serum chemistry, 25-hydroxyvitamin D (vitamin D3) intact parathyroid hormone (iPTH), alkaline phosphatase (ALP), and osteocalcin and were further stratified according to an individual restriction score into 3 groups: mildly, moderately, or severely restricted in daily life due to the underlying disease. Patients with PAD IV showed significantly lower vitamin D3 (P =.0001), and calcium (P =.0001) values and significantly higher iPTH (P =.0001), osteocalcin (P =.0001) and ALP (P =.02) levels as compared to patients with PAD II. Patients considering themselves as severely restricted due to the underlying disease showed lower vitamin D3 and higher iPTH levels than those who described only a moderate (vitamin D3: P <.001; iPTH: P <.01) or mild (vitamin D3: P <.001; iPTH: P <.001) restriction in daily life.

CONCLUSION

Patients with PAD IV, especially those who feel severely restricted due to the disease, are at high risk of developing vitamin D deficiency, secondary hyperparathyroidism, and ultimately osteomalacia due to immobilization and subsequent lack of exposure to sunlight, all of which in turn lead to further deterioration. Monitoring of vitamin D metabolism and vitamin D replacement therapy could be a simple, inexpensive approach to mitigating clinical symptoms and improving quality of life in patients with advanced PAD.

Vitamin D insufficiency among free-living healthy young adults

Long-term vitamin D insufficiency can cause secondary hyperparathyroidism and osteomalacia (1). In addition, there is increasing evidence that vitamin D may protect against common cancers, such as cancer of the colon (–4), prostate (5), and breast (6). Young adults aged 17 to 35 years drink inadequate amounts of milk (7) and are concerned about exposure to the sun because of the fear of developing skin cancer (8,9), which increases the risk of vitamin D insufficiency (10). We sought to examine the prevalence of vitamin D insufficiency in a group of free-living healthy young adults, consisting of mostly health care professionals, in Boston, Massachusetts.