Vitamin D deficiency

Vitamin D status and bone density in recently diagnosed inflammatory bowel disease: the Manitoba IBD Cohort Study

OBJECTIVES

Bone mineral density (BMD) is usually normal at the time of inflammatory bowel disease (IBD) diagnosis. The purpose of this study was to evaluate the role of vitamin D metabolism in recently diagnosed IBD.

METHODS

Adult subjects with recently diagnosed IBD (median 4 yr) were recruited from the University of Manitoba IBD Research Registry into the Manitoba IBD Cohort Study. Baseline BMD and serum 25-hydroxy vitamin D (25OHD) were measured in a nested subgroup of 101 subjects of whom 94 had repeat BMD measurements 2.3 +/- 0.3 yr later.

RESULTS

Only a minority (22 [21.8%]) of recently diagnosed IBD participants had optimal serum 25OHD levels (75 nmol/L or greater). Serum 25OHD was positively correlated with baseline BMD for the lumbar spine, total hip, and total body (all P < 0.05). MANOVA confirmed significant between-group differences in baseline T-scores when vitamin D status was categorized according to serum 25OHD quartile (P < 0.05). Gain in total body BMD between the baseline and follow-up DXA scans was positively correlated with 25OHD (r = 0.20, P < 0.05).

CONCLUSIONS

Poorer vitamin D status correlates with lower baseline BMD at all measurement sites and better vitamin D status is correlated with a gain in total body BMD. Early optimization of vitamin D may play an important role in preventing IBD-related bone disease.

Vitamin D deficiency, cardiac iron and cardiac function in thalassaemia major

Vitamin D25-OH and D1-25OH levels were compared with cardiac R2* (1/T2*), left ventricular ejection fraction (LVEF), age, ferritin and liver iron in 24 thalassaemia major patients. Vitamin D25-OH levels were reduced in 13/24 patients while vitamin D1-25OH levels were often elevated. Vitamin D25-OH levels decreased with age (r(2) = 0.48) and with liver iron (r(2) = 0.20). Cardiac R2* was inversely related with the ratio of D25-OH to D1-25OH levels (r(2) = 0.42). LVEF was also proportional to the D25-OH/D1-25OH ratio (r(2) = 0.49). Vitamin D deficiency may be associated with cardiac iron uptake and ventricular dysfunction in thalassaemia major patients.

Vitamin D deficiency in children and adolescents: epidemiology, impact and treatment

Vitamin D deficiency is highly prevalent among children and adolescents worldwide. The high rates of vitamin D deficiency during childhood are of major public health relevance, given the growing evidence that vitamin D deficiency may play a key role in the pathophysiology of many chronic diseases beyond rickets, including autoimmune conditions, cardiovascular diseases, and cancer. Identification, treatment, and prevention of vitamin D deficiency in childhood may therefore have profound health effects throughout the life span. In this review, we discuss the definitions, epidemiology, clinical implications, and treatment of vitamin D deficiency in children and adolescents.

Prevalence of vitamin D deficiency among healthy infants and toddlers

OBJECTIVES

To determine the prevalence of vitamin D deficiency and to examine whether 25-hydroxyvitamin D (25OHD) concentration varies as a function of skin pigmentation, season, sun exposure, breastfeeding, and vitamin D supplementation.

DESIGN

Cross-sectional sample.

SETTING

Urban primary care clinic.

PARTICIPANTS

Healthy infants and toddlers (N = 380) who were seen for a routine health visit.

OUTCOME MEASURES

Primary outcomes were serum 25OHD and parathyroid hormone levels; secondary measures included data on sun exposure, nutrition, skin pigmentation, and parental health habits. Wrist and knee radiographs were obtained for vitamin D-deficient participants.

RESULTS

The prevalence of vitamin D deficiency (< or =20 ng/mL) was 12.1% (44 of 365 participants), and 146 participants (40.0%) had levels below an accepted optimal threshold (< or =30 ng/mL). The prevalence did not vary between infants and toddlers or by skin pigmentation. There was an inverse correlation between serum 25OHD and parathyroid hormone levels (infants: r = -0.27, P < .001; toddlers: r = -0.20, P = .02). In multivariable models, breastfeeding without supplementation among infants and lower milk intake among toddlers were significant predictors of vitamin D deficiency. In vitamin D-deficient participants, 3 participants (7.5%) exhibited rachitic changes on radiographs, whereas 13 (32.5%) had evidence of demineralization.

CONCLUSIONS

Suboptimal vitamin D status is common among otherwise healthy young children. Predictors of vitamin D status vary in infants vs toddlers, information that is important to consider in the care of these young patients. One-third of vitamin D-deficient participants exhibited demineralization, highlighting the deleterious skeletal effects of this condition.

Vitamin D intake to attain a desired serum 25-hydroxyvitamin D concentration

BACKGROUND

Indirect evidence suggests that optimal vitamin D status is achieved with a serum 25-hydroxyvitamin D [25(OH)D] concentration >75 nmol/L.

OBJECTIVE

We aimed to determine the intake of vitamin D(3) needed to raise serum 25(OH)D to >75 nmol/L.

DESIGN

The design was a 6-mo, prospective, randomized, double-blinded, double-dummy, placebo-controlled study of vitamin D(3) supplementation. Serum 25(OH)D was measured by radioimmunoassay. Vitamin D(3) intake was adjusted every 2 mo by use of an algorithm based on serum 25(OH)D concentration.

RESULTS

A total of 138 subjects entered the study. After 2 dose adjustments, almost all active subjects attained concentrations of 25(OH)D >75 nmol/L, and no subjects exceeded 220 nmol/L. The mean (+/-SD) slope at 9 wk [defined as 25(OH)D change/baseline dose] was 0.66 +/- 0.35 (nmol/L)/(microg/d) and did not differ statistically between blacks and whites. The mean daily dose was 86 microg (3440 IU). The use of computer simulations to obtain the most participants within the range of 75-220 nmol/L predicted an optimal daily dose of 115 microg/d (4600 IU). No hypercalcemia or hypercalciuria was observed.

CONCLUSIONS

Determination of the intake required to attain serum 25(OH)D concentrations >75 nmol/L must consider the wide variability in the dose-response curve and basal 25(OH)D concentrations. Projection of the dose-response curves observed in this convenience sample onto the population of the third National Health and Nutrition Examination Survey suggests a dose of 95 microg/d (3800 IU) for those above a 25(OH)D threshold of 55 nmol/L and a dose of 125 microg/d (5000 IU) for those below that threshold.

Inactivation of the vitamin D receptor enhances susceptibility of murine skin to UV-induced tumorigenesis

1,25-Dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) is the biologically active ligand for the vitamin D receptor (VDR). VDR(-/-) mice have a hair follicle-cycling defect resulting in alopecia. However, mice lacking 25-hydroxyvitamin D(3) 1alpha-hydroxylase (CYP27B1(-/-)), and having no circulating 1,25(OH)(2)D(3), have normal follicular function. These mouse models indicate that VDR functions independently of 1,25(OH)(2)D(3) in regulating hair-follicle cycling. Here, we show that VDR(-/-) mice rapidly develop chemically induced skin tumors, whereas CYP27B1(-/-) and wild-type mice do not, indicating that VDR, and not the 1,25(OH)(2)D(3) ligand, is essential for protection against skin tumorigenesis. Because the majority of human skin cancer results from exposure to UV, the susceptibility of VDR(-/-) mice to this carcinogen was also evaluated. VDR(-/-) mice developed UV-induced tumors more rapidly and with greater penetrance than did VDR(+/+) mice. p53 protein levels were upregulated at similar rates in UV-treated keratinocytes of VDR(-/-) and VDR(+/+) mice. However, rates of thymine-dimer repair and UV-induced apoptosis were significantly lower in VDR(-/-) epidermis compared with the wild type epidermis. UV-induced epidermal thickening was also attenuated in VDR(-/-) skin, indicating that VDR plays a critical role in the repair and removal of severely damaged keratinocytes and adaptation of the skin to chronic UV exposure.

Shedding light on vitamin D and integrative oncology

Studies show an important relationship between vitamin D and malignancies, both in prevention and treatment. The extraskeletal actions of vitamin D relevant to oncology include being proapoptotic, antimetastatic, antiangiogenic, antiinflammatory, prodifferentiating, and immunomodulating. Widespread and severe vitamin D deficiencies exist worldwide. Decreased sun exposure, caused by lifestyle changes, as well as fear of skin cancers, is the main cause of these deficiencies. Recommended daily oral intakes, as well as suggested blood levels, are below optimal levels suggested by studies. Improvement in vitamin D status, through lifestyle changes and supplementation, can be of profound benefit regarding the occurrence and mortality of malignancies.

Evidence for the necessity to systematically assess micronutrient status prior to bariatric surgery

BACKGROUND

Bariatric surgery has been proven the most effective treatment of morbid obesity, but micronutrient deficiency following bariatric surgery is a major concern. Increasing evidence points to a generally poor micronutrient status in obese subjects.

METHODS

We assessed micronutrient status in 232 morbidly obese subjects (BMI > or = 35 kg/m(2)) prior to bariatric surgery. Serum albumin, calcium, phosphate, magnesium, ferritin, hemoglobin, zinc, folate, vitamin B(12), 25-OH vitamin D(3), and intact parathormone (iPTH) were determined. In a sub-sample of 89 subjects, we additionally assessed copper, selenium, vitamin B(1), B(3), B(6), A, and E levels.

RESULTS

Deficiencies were found in 12.5% of the subjects for albumin, 8.0% for phosphate, 4.7% for magnesium, 6.9% for ferritin, 6.9% for hemoglobin, 24.6% for zinc, 3.4% for folate, and 18.1% for vitamin B(12). In addition, 25.4% showed a severe 25-OH vitamin D(3) deficiency, which was accompanied by a secondary hyperparathyroidism in 36.6% cases. Prevalence of albumin deficiency (p < 0.007) and of anemia (p < 0.003; in women only) significantly increased with BMI. Of note, 48.7% of the subjects showed at least one of the most prevalent deficiencies, i.e., vitamin B(12), zinc and severe 25-OH vitamin D(3) deficiency. In the sub-sample, 32.6% showed a selenium, 5.6% a vitamin B(3), 2.2% a vitamin B(6), and 2.2% a vitamin E deficiency. Copper, vitamin B(1), and vitamin A deficiency was found in none of the subjects.

CONCLUSION

Data indicate a high prevalence of micronutrient deficiencies in morbidly obese subjects. Based on these results, we strongly recommend a systematic assessment of the micronutrient status in all candidates for bariatric surgery.

Hypovitaminosis D in African Americans residing in Memphis, Tennessee with and without heart failure

BACKGROUND

Factors contributing to heart failure (HF) in African Americans (AA) are under investigation. Reduced 25(OH)D confers increased cardiovascular risk, including HF.

METHODS

We monitored serum 25(OH)D, 1,25(OH)2D3, parathyroid hormone (PTH), and creatinine clearance in 102 AA residing in Memphis: 58 hospitalized with decompensated HF of >or=4 weeks in 34 (21 men; 53.3 +/- 1.8 years) or of 1 to 2 weeks in 24 (17 men; 49.6 +/- 2.4 years) and associated with a dilated cardiomyopathy and reduced ejection fraction (<35%); 19 outpatients with compensated HF (14 men; 52.6 +/- 2.7 years) with comparable ejection fraction; 16 outpatients (9 men; 55.4 +/- 2.9 years) with heart disease, but without HF; and 9 healthy volunteers (3 men; 35.8 +/- 3.5 years).

RESULTS

Serum 25(OH)D <or=30 ng/mL was found in 96% and 90% with protracted or short-term decompensated HF, where it was of moderate to marked severity (<20 ng/mL) in 83% and 76%, respectively. In patients with either compensated or no HF, 25(OH)D <30 ng/mL was found in 95% and 100%, respectively, and in 30% of volunteers. Normal serum 1,25(OH)2D3 did not differ between patients. Serum PTH >65 pg/mL was found in all AA with decompensated HF of >or=4 weeks (132.4 +/- 12.0 pg/mL) and 67% with 1 to 2 weeks duration (82.3 +/- 7.9 pg/mL), but only 11% with compensated HF (45.8 +/- 6.1 pg/mL), 12% without HF (29.6 +/- 5.4 pg/mL), and none of the volunteers (31.1 +/- 3.9 pg/mL). Creatinine clearance did not differ between patient groups.

CONCLUSIONS

Hypovitaminosis D is prevalent amongst AA residing in Memphis, with or without HF. Elevations in serum PTH in keeping with secondary hyperparathyroidism are only found in AA with decompensated HF, where hypovitaminosis D and other factors are contributory.

Association of oral calcitriol with improved survival in nondialyzed CKD

Parenteral vitamin D is associated with improved survival among long-term hemodialysis patients. Among nondialyzed patients with chronic kidney disease (CKD), oral activated vitamin D reduces parathyroid hormone levels, but the impact on clinical outcomes is unknown. We evaluated associations of oral calcitriol use with mortality and dialysis dependence in 1418 nondialysis patients with CKD and hyperparathyroidism in the Veterans' Affairs Consumer Health Information and Performance Sets database. Incident calcitriol users and nonusers were selected on the basis of stages 3 to 4 CKD, hyperparathyroidism, and the absence of hypercalcemia before calcitriol use and then were matched by age and estimated kidney function. During a median follow-up of 1.9 yr, 408 (29%) patients died and 217 (16%) initiated long-term dialysis. After adjustment for demographics; comorbidities; estimated kidney function; medications; and baseline levels of parathyroid hormone, calcium, and phosphorous, oral calcitriol use was associated with a 26% lower risk for death (95% confidence interval 5 to 42% lower; P = 0.016) and a 20% lower risk for death or dialysis (95% confidence interval 1 to 35% lower; P = 0.038). The association of calcitriol with improved survival was not statistically different across baseline parathyroid hormone levels. Calcitriol use was associated with a greater risk for hypercalcemia. In conclusion, oral calcitriol use is associated with lower mortality in nondialysis patients with CKD.

Recruitment and in situ renewal regulate rapid accumulation of CD11c+ cells in the lung following intranasal superantigen challenge

BACKGROUND

Staphylococcusaureus, a primary source of bacterial superantigen, is known to colonize the human respiratory tract and has been implicated in airway inflammation. The potential pathological effect of staphylococcal enterotoxins on the respiratory tract necessitates a detailed understanding of how they regulate innate immune cells, particularly CD11c-expressing dendritic cells (DCs).

METHODS

C57BL/6 mice were challenged intranasally with staphylococcal enterotoxin A (SEA) and at indicated time points lung tissue was perfused, digested and analyzed for CD11c+ expressing cells.

RESULTS

The pulmonary CD11c+ cells can be divided into two major populations based on their MHC II expression. One day following intranasal SEA challenge, there was rapid accumulation of CD11c+ cells expressing medium to high levels of MHC II. The peak accumulation of CD11c+ MHC II- population was observed 2 days after SEA challenge; however, careful examination of this cell population revealed that they were heterogeneous, being comprised of cells bearing CD3, CD19, NK1.1 and F4/80 along with varying levels of CD11c. Nevertheless, there was a 2-fold increase of CD11c+ MHC II- (CD3- CD19- NK1.1- F4/80-) cells in the lungs.

CONCLUSION

The mechanism of increase in the CD11c+ MHC II- immune progenitor population was mainly due to cellular division rather than migration from blood to lung. In contrast, the early and rapid accumulation of CD11c+ MHC II(hi) cells, conventionally known as DCs, in the lung on day 1 was mostly due to migration from blood. Thus this study examines the pulmonary innate immune response to a powerful immune stimulus.

Treatment and management of osteoporosis-pseudoglioma syndrome

Osteoporosis-pseudoglioma syndrome (OPPG; MIM 259770) is a very rare genetic disorder with an autosomal recessive mode of inheritance, characterized by congenital or infancy-onset visual loss and skeletal fragility, diagnosed during childhood. This syndrome can lead to severe disability and chronic bone pain. Low-density lipoprotein receptor-related protein 5 (LRP5) is the gene mutated and inactivated in OPPG, and plays a pivotal role in bone accrual and skeletal remodeling by controlling bone formation through activators, such as Wnt proteins, or inhibitors, such as DKK1. OPPG should be differentiated from osteogenesis imperfecta and child abuse by clinicians. Eye examination, coupled to bone phenotype and research of LRP5 mutation, are key points to diagnose OPPG. Chronic pain should be managed correctly in this syndrome with severe functional disability. Bisphosphonates allows fracture prevention, the catch-up of bone mineral density and improvement in mobility in children with OPPG. New drugs favoring osteoblast function and osteoclast inhibition are potential candidates in the treatment of OPPG.

Racial and seasonal differences in 25-hydroxyvitamin D detected in maternal sera frozen for over 40 years

Serum banks from large, decades-old epidemiological studies provide a valuable opportunity to explore the contributions of in utero vitamin D exposure to fetal origins of adult diseases. We compared 25-hydroxyvitamin D (25(OH)D) by race and season (two powerful predictors of vitamin D status) in sera frozen for >or= 40 years with sera frozen for <or= 2 years to determine whether 25(OH)D is stable enough to test vitamin D-related hypotheses. Data and sera came from seventy-nine pregnant women at 29-32 weeks' gestation in the Boston Collaborative Perinatal Project (CPP; 1959-66) and 124 women at 20-36 weeks' gestation in a 2003-2006 Pittsburgh cohort study. Multivariable linear regression models were used to test main and joint effects of race and season after confounder adjustment. In both cohorts, serum 25(OH)D levels were lower among black than white women (CPP 33.3 v. 46.7 nmol/l, P<0.01; Pittsburgh 47.1 v. 89.6 nmol/l; P<0.0001) and in winter than summer (CPP 32.7 v. 47.6 nmol/l, P<0.0001; Pittsburgh 66.7 v. 89.8 nmol/l, P<0.001), with no evidence of a race x season interaction in either cohort. Differences remained significant after confounder adjustment. When CPP and Pittsburgh results were compared, there was no significant difference in the race or season effects. The similarity in the relative change in 25(OH)D in these cohorts by two powerful predictors of vitamin D status suggests that, even if 25(OH)D deteriorated somewhat, it did so similarly across samples. Therefore, trends could be obtained from the decades-old serum data that would be relevant in exploring vitamin D-related hypotheses in future studies.

Hypovitaminosis D in chronic kidney disease

BACKGROUND AND OBJECTIVES

Recent studies show high prevalence of suboptimal 25-hydroxyvitamin D levels in chronic kidney disease patients. This study sought to test the hypothesis that the prevalence of 25-hydroxyvitamin D deficiency is significantly higher in chronic kidney disease patients and, in diabetic nephropathy, low serum 25-hydroxyvitamin D is associated with abnormal serum parathyroid hormone, bone mineral density, and coronary artery calcification.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Study A used data from the Third National Health and Nutrition Examination Survey. Study B was a post hoc analysis of an observational study of coronary artery calcification in non-dialysis-dependent diabetic nephropathy.

RESULTS

In study A, the adjusted odds for 25-hydroxyvitamin D deficiency were 32% higher in chronic kidney disease patients. This higher prevalence of 25-hydroxyvitamin D deficiency, however, could not be explained by differences in total vitamin D intakes. The consequences of suboptimal 25-hydroxyvitamin D levels were analyzed in 146 patients with diabetic nephropathy. The significant, inverse relationship between serum 25-hydroxyvitamin D and parathyroid hormone levels was attenuated to a nonsignificant level on multivariate adjustment. There was a significant, inverse relationship between bone mineral density and coronary artery calcification scores; neither was independently associated with serum 25-hydroxyvitamin D. The serum 25-hydroxyvitamin D levels declined modestly in 72 patients studied after 12.4 +/- 0.4 mo.

CONCLUSIONS

25-Hydroxyvitamin D deficiency is more common in chronic kidney disease, but this higher prevalence is unlikely to be a result of lower vitamin D intakes. The consequences of suboptimal 25-hydroxyvitamin D levels remain to be definitively elucidated.

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.

Calcium and vitamin D: skeletal and extraskeletal health

Vitamin D is known for its role in calcium homeostasis for optimal skeletal health. It was previously believed that only elderly or hospitalized patients were at risk for vitamin D insufficiency, but many people in the general US population have insufficient levels of 25-hydroxyvitamin D (25D). According to the Third National Health and Nutrition Examination Survey, 61% of white and 91% of black Americans suffer from vitamin D insufficiency (25D < 32 ng/mL). Recent studies have demonstrated that a minimum 25(OH)D level of 32 ng/mL is necessary for optimal protection from fracture and intestinal absorption of calcium. Recently, vitamin D has been recognized as important for extraskeletal functions such as immune function, cancer prevention, and hypertension prevention. We review the role of vitamin D in skeletal health and present data on vitamin D in other extraskeletal diseases, with special emphasis on the rheumatology patient.

Vitamin D assessment in population-based studies: a review of the issues

In the past decade, research on the relation between vitamin D exposure and disease in population-based studies has increased exponentially. These studies have involved measurement of vitamin D exposure by means of several methods: blood assays, self-reported dietary and supplemental intakes, and sunlight exposure questionnaires or diaries. As with all exposure measurements, researchers must consider the validity of their assessment tools for capturing vitamin D exposure. The purpose of this article is to summarize our current understanding of the various approaches to measuring vitamin D status within populations as reviewed at the 2007 Experimental Biology symposium, "Assessment of Vitamin D in Population-Based Studies." In summary, serum 25-hydroxyvitamin D is the accepted biomarker for short-term vitamin D status, but estimates of long-term dietary and supplemental intakes of vitamin D and long-term sunlight exposure may be the most logistically feasible indicators of lifetime vitamin D exposure in population-based studies. Also discussed are issues investigators should consider when analyzing relations between vitamin D exposure and disease outcomes in population-based studies as well as research avenues that need further exploration. The best method for assessing vitamin D status in population-based studies will depend primarily on the research question asked and the critical window of vitamin D exposure hypothesized to be most important.

Vitamin D deficiency: a worldwide problem with health consequences

Vitamin D deficiency is now recognized as a pandemic. The major cause of vitamin D deficiency is the lack of appreciation that sun exposure in moderation is the major source of vitamin D for most humans. Very few foods naturally contain vitamin D, and foods that are fortified with vitamin D are often inadequate to satisfy either a child's or an adult's vitamin D requirement. Vitamin D deficiency causes rickets in children and will precipitate and exacerbate osteopenia, osteoporosis, and fractures in adults. Vitamin D deficiency has been associated with increased risk of common cancers, autoimmune diseases, hypertension, and infectious diseases. A circulating level of 25-hydroxyvitamin D of >75 nmol/L, or 30 ng/mL, is required to maximize vitamin D's beneficial effects for health. In the absence of adequate sun exposure, at least 800-1000 IU vitamin D3/d may be needed to achieve this in children and adults. Vitamin D2 may be equally effective for maintaining circulating concentrations of 25-hydroxyvitamin D when given in physiologic concentrations.

Sunlight exposure assessment: can we accurately assess vitamin D exposure from sunlight questionnaires?

The purpose of this review is to summarize the peer-reviewed literature in relation to sunlight exposure assessment and the validity of using sunlight exposure questionnaires to quantify vitamin D status. There is greater variability in personal ultraviolet (UV) light exposure as the result of personal behavior than as the result of ambient UV light exposure. Although statistically significant, the correlation coefficients for the relation between personal report of sun exposure and ambient UV light measured by dosimetry (assessment of radiation dose) are relatively low. Moreover, the few studies to assess the relation between sunlight measures and serum 25-hydroxyvitamin D show low correlations. These low correlations may not be surprising given that personal factors like melanin content in skin and age also influence cutaneous synthesis of vitamin D. In summary, sunlight exposure questionnaires currently provide imprecise estimates of vitamin D status. Research should be directed to develop more objective, nonintrusive, and economical measures of sunlight exposure to quantify personal vitamin D status.

Sickle cell bone disease: response to vitamin D and calcium

Bone disease with osteoporosis and osteomalacia are common in sickle cell disease (SCD). Some patients have vitamin D deficiency and low bone mineral density (BMD). The role of vitamin D and calcium supplementation to restore bone health in SCD has not been well studied. In 14 adults with SCD, we measured 25(OH)D (25-hydroxyvitamin D) and BMD at the femoral neck, lumbar spine, and distal third of the ulna plus radius, along with markers of bone resorption (CTx; C-terminal component of pro-collagen type I) and bone formation (osteocalcin) before and after 12 months of vitamin D(2) and calcium carbonate treatment. Pretreatment, all patients were vitamin D deficient with a mean 25(OH)D level of 11.6 [corrected] +/- 4 [corrected] ng/ml, had low BMD at the lumbar spine (L-spine), 0.87 +/- 0.11 g/cm(2) (mean Z-score of -2.6 3 +/- 0.71 SD and T score of -2.31 +/- 0.75 SD), femoral neck, 0.8 +/- 0.18 g/cm(2) (mean Z-score -1.36 +/- 0.84, T-score -1.14 +/- 0.75), and the distal radius and ulna, 0.6 +/- 0.17 g/cm(2) (mean Z-score -1.18 +/- 0.79, T-score -1.01 +/- 0.74) and had elevated CTx (0.87 +/- 0.5 ng/ml) and osteocalcin levels (12.3 +/- 3.7 ng/mul). After treatment, all patients corrected their 25(OH)D level (34.6 [corrected] +/- 11 [corrected] ng/ml) (P < 0.001) with a 3.6% +/- 3.9% increase in BMD at the L-spine (P = 0.009), 4.6% +/- 8.5% increase at the femoral neck (P = 0.05) and 6.5% +/- 12.6% increase at the distal radius plus ulna (P = 0.09). CTx, osteocalcin, and PTH(i) levels were unchanged. Treatment of adult SCD with vitamin D and calcium can restore 25(OH)D levels to normal and improve BMD, but, markers of bone resorption remained unchanged. Screening for vitamin D deficiency and BMD in SCD patients seems warranted.

Safety of parathyroid hormone for the treatment of osteoporosis

Teriparatide (recombinant human 1-34 parathyroid hormone) has been registered for the treatment of postmenopausal osteoporosis and osteoporosis in men for more than 5 years, whereas 1-84 parathyroid hormone has just recently been registered in Europe for osteoporosis management. Therefore, more data are available regarding the long-term safety of teriparatide. The issues to be considered are the effects of the registered dose of teriparatide (20 microg/day) on the incidence of hypercalcemia, hypercalciuria, and hyperuricemia, and the US Food and Drug Administration's "black-box" warning regarding osteogenic sarcoma in the rat model. This review discusses these issues and provides the author's extensive clinical experience and advice on the use of teriparatide in clinical practice.

Vitamin D status in gastrointestinal and liver disease

PURPOSE OF REVIEW

The purpose of this review is to report on the vitamin D status and its relationship with bone health in individuals with gastrointestinal and liver disorders. In addition, recommendations regarding replacement and maintenance of optimal vitamin D stores, as well as the state of knowledge regarding its effect on the disease through its actions on the immune system, will be reviewed.

RECENT FINDINGS

The scientific community has revised upward the serum levels of vitamin D considered optimal, and doses of vitamin D much larger than those currently recommended may be needed to maintain these levels, especially in individuals with gastrointestinal and liver disorders. The relationship between vitamin D and bone health in this population is controversial. The role of vitamin D in the regulation of the immune system continues to be elucidated.

SUMMARY

Hypovitaminosis D is prevalent among individuals with gastrointestinal and liver disease. Although replacement and supplementation guidelines have not been well defined, practitioners should aim for a serum 25-hydroxyvitamin D level of at least 32 ng/ml. The contribution of vitamin D to the bone health of these individuals and its role in altering disease course through its actions on the immune system remain to be elucidated.

Vitamin D therapy

The fat-soluble vitamin D prohormones, ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3), are essential for the efficient intestinal absorption of calcium and phosphate and the subsequent mineralization of bone. Inadequate vitamin D leads to chronic secondary hyperparathyroidism and osteoporosis. The increasing prevalence of osteoporosis has paralleled a pandemic of vitamin D insufficiency. Based on observational and prospective trials with clinical end points, the standards for vitamin D sufficiency have been recently revised. All patients with osteopenia or osteoporosis should be monitored with a reliable assay to maintain serum 25-hydroxyvitamin D levels more than 32 ng/dL. Patients who are taking bisphosphonates and those with coexisting primary hyperparathyroidism are not exempt from taking supplemental vitamin D.

Low prevalence of vitamin D deficiency among adolescents with anorexia nervosa

Fifty adolescents with AN and 200 healthy girls underwent vitamin D screening. Girls with AN reported exceptional compliance with vitamin D supplementation and PTH concentrations were lower. Vitamin D deficiency was less common in the group with AN, but when race was considered, the trend was no longer significant.

INTRODUCTION

The objective of this study was to determine whether patients with anorexia nervosa (AN) are more compliant with supplementation and have a lower prevalence of vitamin D deficiency than healthy controls.

METHODS

Fifty adolescents with AN and 200 controls were compared using anthropometric and lifestyle data, serum 25-hydroxyvitamin D (25OHD) and parathyroid hormone (PTH) concentrations, and prevalence of vitamin D deficiency.

RESULTS

The prevalence of deficiency (<20 ng/mL) was 2% in the AN group vs. 24% among controls (p = 0.003). 25OHD was similar among white participants with AN and white controls (39.5 vs. 36.0 ng/mL, p = 0.20), but higher than in non-white controls (20.6 ng/mL). Significantly more girls with AN reported vitamin D supplementation (86%) than the full control (14%) or white subgroup (27%) (p < 0.001). Participants with AN had lower PTH concentrations than controls, (27.8 vs. 47.4 pg/mL, p = 0.009), a trend that lost significance after age and race adjustment (41.7 pg/mL, p = 0.12).

CONCLUSIONS

Compared to healthy controls, adolescents with AN had a lower prevalence of vitamin D deficiency and PTH concentration. However, 25OHD and PTH concentrations were similar after adjustment for race and age. The trend of lower PTH levels in adolescents with AN, accompanied by exceptional compliance with supplementation, may have bone health implications for these patients.

Vitamin D2 is as effective as vitamin D3 in maintaining circulating concentrations of 25-hydroxyvitamin D

CONTEXT

Two reports suggested that vitamin D2 is less effective than vitamin D3 in maintaining vitamin D status.

OBJECTIVE

Our objective was to determine whether vitamin D2 was less effective than vitamin D3 in maintaining serum 25-hydroxyvitamin D levels or increased the catabolism of 25-hydroxyvitamin D3.

SUBJECTS AND DESIGN

This was a randomized, placebo-controlled, double-blinded study of healthy adults ages 18-84 yr who received placebo, 1000 IU vitamin D3, 1000 IU vitamin D2, or 500 IU vitamin D2 plus 500 IU vitamin D3 daily for 11 wk at the end of the winter.

RESULTS

Sixty percent of the healthy adults were vitamin D deficient at the start of the study. The circulating levels of 25-hydroxyvitamin D (mean+/-sd) increased to the same extent in the groups that received 1000 IU daily as vitamin D2 (baseline 16.9+/-10.5 ng/ml; 11 wk 26.8+/-9.6 ng/ml), vitamin D3 (baseline 19.6+/-11.1 ng/ml; 11 wk 28.9+/-11.0 ng/ml), or a combination of 500 IU vitamin D2 and 500 IU vitamin D3 (baseline 20.2+/-10.4 ng/ml; 11 wk 28.4+/-7.7 ng/ml). The 25-hydroxyvitamin D3 levels did not change in the group that received 1000 IU vitamin D2 daily. The 1000 IU dose of vitamin D2 or vitamin D3 did not raise 25-hydroxyvitamin D levels in vitamin D-deficient subjects above 30 ng/ml.

CONCLUSION

A 1000 IU dose of vitamin D2 daily was as effective as 1000 IU vitamin D3 in maintaining serum 25-hydroxyvitamin D levels and did not negatively influence serum 25-hydroxyvitamin D3 levels. Therefore, vitamin D2 is equally as effective as vitamin D3 in maintaining 25-hydroxyvitamin D status.

Vitamin D and Peritoneal Dialysis

Chronic kidney disease – mineral and bone disorder (CKD–MBD) is a cause of significant morbidity and mortality in patients with long-standing kidney disease. Management of secondary hyperparathyroidism includes the use of phosphorus-binding agents and treatment with activated vitamin D compounds, better referred to as vitamin D receptor agonists (VDRAs). In an effort to maximize the therapeutic response while reducing the adverse effects of calcitriol, the naturally synthesized hormone, the use of intravenous administration and several selective VDRAs have been developed. Recently, oral preparations of these selective VDRAs have become available, enabling their use in the peritoneal dialysis (PD) population. The present report reviews the data concerning the use of oral VDRAs for the treatment of hyperparathyroidism in PD patients. The data, although limited, appear to support the use of oral paricalcitol as the VDRA in PD patients. In addition, traditional teaching focuses only on therapy with VDRAs, ignoring vitamin D replacement in CKD stage 5. However, given the potential benefits of calcidiol (25-OH-D) repletion and the rampant 25-OH-D deficiency in the PD population, our opinion is that screening for and treating that deficiency should extend beyond early CKD and also include PD patients.

On the epidemiology of influenza

The epidemiology of influenza swarms with incongruities, incongruities exhaustively detailed by the late British epidemiologist, Edgar Hope-Simpson. He was the first to propose a parsimonious theory explaining why influenza is, as Gregg said, "seemingly unmindful of traditional infectious disease behavioral patterns." Recent discoveries indicate vitamin D upregulates the endogenous antibiotics of innate immunity and suggest that the incongruities explored by Hope-Simpson may be secondary to the epidemiology of vitamin D deficiency. We identify – and attempt to explain – nine influenza conundrums: (1) Why is influenza both seasonal and ubiquitous and where is the virus between epidemics? (2) Why are the epidemics so explosive? (3) Why do they end so abruptly? (4) What explains the frequent coincidental timing of epidemics in countries of similar latitude? (5) Why is the serial interval obscure? (6) Why is the secondary attack rate so low? (7) Why did epidemics in previous ages spread so rapidly, despite the lack of modern transport? (8) Why does experimental inoculation of seronegative humans fail to cause illness in all the volunteers? (9) Why has influenza mortality of the aged not declined as their vaccination rates increased? We review recent discoveries about vitamin D's effects on innate immunity, human studies attempting sick-to-well transmission, naturalistic reports of human transmission, studies of serial interval, secondary attack rates, and relevant animal studies. We hypothesize that two factors explain the nine conundrums: vitamin D's seasonal and population effects on innate immunity, and the presence of a subpopulation of "good infectors." If true, our revision of Edgar Hope-Simpson's theory has profound implications for the prevention of influenza.

Diagnosis and treatment of vitamin D deficiency

The recent discovery--in a randomised, controlled trial--that daily ingestion of 1100 IU of colecalciferol (vitamin D) over a 4-year period dramatically reduced the incidence of non-skin cancers makes it difficult to overstate the potential medical, social and economic implications of treating vitamin D deficiency. Not only are such deficiencies common, probably the rule, vitamin D deficiency stands implicated in a host of diseases other than cancer. The metabolic product of vitamin D is a potent, pleiotropic, repair and maintenance, secosteroid hormone that targets > 200 human genes in a wide variety of tissues, meaning it has as many mechanisms of action as genes it targets. A common misconception is that government agencies designed present intake recommendations to prevent or treat vitamin D deficiency. They did not. Instead, they are guidelines to prevent particular metabolic bone diseases. Official recommendations were never designed and are not effective in preventing or treating vitamin D deficiency and in no way limit the freedom of the physician--or responsibility--to do so. At this time, assessing serum 25-hydroxy-vitamin D is the only way to make the diagnosis and to assure that treatment is adequate and safe. The authors believe that treatment should be sufficient to maintain levels found in humans living naturally in a sun-rich environment, that is, > 40 ng/ml, year around. Three treatment modalities exist: sunlight, artificial ultraviolet B radiation or supplementation. All treatment modalities have their potential risks and benefits. Benefits of all treatment modalities outweigh potential risks and greatly outweigh the risk of no treatment. As a prolonged 'vitamin D winter', centred on the winter solstice, occurs at many temperate latitudes, < or = 5000 IU (125 microg) of vitamin D/day may be required in obese, aged and/or dark-skinned patients to maintain adequate levels during the winter, a dose that makes many physicians uncomfortable.

Current concepts in bone and reproductive health in adolescents with anorexia nervosa

Anorexia nervosa (AN) initiates an adaptive response at the level of the hypothalamus, which results in a complex interplay involving most elements of the neuroendocrine axis. Consequences of onset of disease in adolescence include amenorrhoea, pubertal arrest with potential loss of target height, and osteoporosis with reduced capacity for future attainment of peak bone mass. With recovery, delay in restoration of menses is common. Hormonal therapies for restoration of bone mineral density (BMD) in adolescents have shown limited efficacy. This review will discuss the reproductive endocrine effects of AN in adolescence, and discuss new investigative tools for monitoring restoration of reproductive function and BMD in this population.

Prevalence and severity of disordered mineral metabolism in Blacks with chronic kidney disease

Disorders of mineral metabolism develop early in chronic kidney disease, but it appears that Blacks with stage-5 disease have more severe secondary hyperparathyroidism than other races. We measured levels of parathyroid hormone, calcium, phosphorus, 25-hydroxyvitamin D (25D) and 1,25-dihydroxyvitamin D (1,25D) in 227 Black and 1633 non-Black participants in the SEEK study, a multi-center cohort of patients with early chronic kidney disease. Overall, Blacks had similar 1,25D levels compared with non-Blacks, but significantly lower levels of 25D with higher levels of calcium, phosphorus, and parathyroid hormone, and were significantly more likely to have hyperphosphatemia than non-Blacks. In multivariable analyses adjusted for age, gender, estimated glomerular filtration rate, body mass index, and diabetes, Blacks had significantly lower 25D and higher parathyroid hormone levels than non-Blacks, with the latter parameter remaining significant after further adjustment for calcium, phosphorus, 25D, and 1,25D. The association between Black race and secondary hyperparathyroidism, independent of known risk factors, suggests that novel mechanisms contribute to secondary hyperparathyroidism in Blacks with chronic kidney disease.

25-hydroxyvitamin D, IGF-1, and metabolic syndrome at 45 years of age: a cross-sectional study in the 1958 British Birth Cohort

OBJECTIVE

Hypovitaminosis D and reduced IGF-1 are associated, individually, with metabolic syndrome. Physiological interactions between vitamin D and IGF-1 are reported; this is the first study to investigate their combined associations with metabolic syndrome prevalence.

RESEARCH DESIGN AND METHODS

Data on 25-hydroxyvitamin D (25(OH)D), IGF-1, and metabolic syndrome abnormalities (abdominal obesity; raised A1C, blood pressure, and triglycerides; and low HDL cholesterol) were collected from 6,810 British white subjects in the 1958 cohort, surveyed during 2002-2004 (age 45 years).

RESULTS

IGF-1 concentrations increased with 25(OH)D up to approximately 75-85 nmol/l but not thereafter. Both 25(OH)D and IGF-1 were inversely associated with metabolic syndrome. There was an interaction between 25(OH)D and IGF-1 (P = 0.025) on metabolic syndrome prevalence: IGF-1 was not significantly associated with metabolic syndrome among those with the lowest levels of 25(OH)D (P > 0.09), whereas higher 25(OH)D was associated with metabolic syndrome at all IGF-1 concentrations (P

CONCLUSIONS

Serum 25(OH)D is inversely associated with metabolic syndrome, whereas the inverse association with IGF-1 was found only among those without hypovitaminosis D. These results suggest that metabolic syndrome prevalence is the lowest when both 25(OH)D and IGF-1 are high.

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MESH Headings

• Blood Pressure
• Body Height
• Body Weight
• Cross-Sectional Studies
• Female
• Health Surveys
• Humans
• Incidence
• Insulin-Like Growth Factor I/metabolism
• Male
• Metabolic Syndrome/blood
• Metabolic Syndrome/epidemiology
• Middle Aged
• Surveys and Questionnaires
• United Kingdom/epidemiology
• Vitamin D/analogs & derivatives
• Vitamin D/blood
• Vitamin D Deficiency/blood
• Vitamin D Deficiency/epidemiology
• White People

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Grants

• G0000934 Medical Research Council
• G0400546 Medical Research Council
• PHCS/C4/4/016 Department of Health

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Affiliation(s)

Elina Hyppönen Center for Paediatric Epidemiology and Biostatistics, Institute of Child Health, 30 Guilford St., London, WC1N 1EH, UK.
Barbara J Boucher
Diane J Berry
Chris Power

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Collaborators Collapse

Vitamin status in morbidly obese patients: a cross-sectional study

BACKGROUND

Morbid obesity is associated with low circulating concentrations of 25-hydroxyvitamin D. Few data on the concentrations of other vitamins in morbidly obese patients are available.

OBJECTIVE

The objective was to compare serum and blood vitamin concentrations in morbidly obese patients with those in healthy subjects.

DESIGN

In 2 public hospital departments (southeast Norway), we prospectively examined 110 consecutive patients (76 women) and 58 healthy controls (30 women) not taking multivitamin supplements. Patients and controls did not differ significantly in age or ethnicity. The mean (+/-SD) body mass index (in kg/m(2)) was 45 +/- 7 in the patients and was 24 +/- 3 in the controls. Patients with vitamin concentrations lower than 2 SD below the sex-specific mean in controls were considered to have inadequate vitamin status.

RESULTS

The morbidly obese women and men had significantly lower concentrations of vitamin B-6, vitamin C, 25-hydroxyvitamin D, and lipid-standardized vitamin E than did the healthy controls (P < 0.01 for each). The status of these vitamins was inadequate in a substantial proportion of the patients (11-38%). The status of vitamins A, B-1, B-2, and B-12 and of folic acid was adequate in most of the patients (95-100%). A moderately elevated C-reactive protein concentration was associated with lower vitamin A, B-6, and C concentrations. In a multiple regression analysis, concentrations of alkaline phosphatase (inverse relation) and vitamin C were the strongest determinants of serum vitamin B-6 concentrations.

CONCLUSIONS

Low concentrations of vitamin B-6, vitamin C, 25-hydroxyvitamin D, and vitamin E adjusted for lipids are prevalent in morbidly obese Norwegian patients seeking weight-loss treatment.