Plasma 25-Hydroxyvitamin D Responses of Younger and Older Men to Three Weeks of Supplementation with 1800 IU/day of Vitamin D

Objective: The objective of this study was to compare changes in plasma 25-hydroxyvitamin D (25(OH)D) levels of younger and older men after three weeks of oral vitamin D supplementation.

Methods: Nine younger men (22 to 28 years) and nine older men (65 to 73 years) with self-reported vitamin D intakes below 200 IU/d were enrolled in February and randomized to 1800 IU/d of ergocalciferol (vitamin D₂, n=11) or to a control group (n=7) and followed for three weeks. Blood was collected at baseline, and after one, two and three weeks for measurement of plasma concentrations of total 25(OH)D, 25(OH)D₂ and 25(OH)D₃.

Results: In both the younger and older supplemented men, 25(OH)D₂ and total 25(OH)D concentrations increased significantly during the study, whereas values of these metabolites did not change in younger or older control subjects. No group showed significant changes in 25-hydroxyvitamin D₃. There was a significant interaction between age group and supplement group, suggesting that the effect of vitamin D₂ supplementation on changes in 25(OH)D₂ changes with age. The mean increase in 25(OH)D₂ was greater in the younger supplemented men than in the older supplemented men (37±9 nmol/L vs. 19.5 nmol/L, p=0.027), and this accounted for their significantly greater increase in total 25(OH)D.

Conclusion: These data are consistent with an age-related decline in the absorption, transport or liver hydroxylation of orally-consumed vitamin D.     

The Effect of Vitamin D Supplementation on Glycemic Control and Lipid Profile in Patients with Type 2 Diabetes Mellitus

Aim: The aim of this study was to evaluate the effect of vitamin D supplementation in patients with type 2 diabetes mellitus (T2DM) with regard to their glycemic control and lipid profile.

Methods: One hundred subjects with T2DM were recruited and given 4500 IU/day of vitamin D for 2 months. 25-Hydroxyvitamin D [25(OH)D], fasting blood glucose (FBG), glycosylated hemoglobin A1c (HbA1c), and lipid profile were measured pre- and postsupplementation.

Results: There was a significant increase in the mean value of 25(OH)D level after supplementation (baseline level 16 ± 5.3 ng/ml vs. after supplement level 49.2 ± 17.7 ng/ml, p < 0.05). Both FBG and HbA1c but not lipid profile were significantly decreased after supplementation. However, the univariate general linear model between 25(OH)D percentiles and lipid profile levels showed that diabetic subjects with high 25(OH)D levels (>61 ng/ml) had significantly lower levels of total cholesterol and low-density lipoprotein cholesterol (LDL-C) in comparison to those in the low or middle percentiles. Furthermore, participants in a higher percentile had a significantly higher level of high-density lipoprotein cholesterol (HDL-C) than those in the middle percentile. Lipid profile levels were not affected by the supplement except for triglycerides (TG) levels in females, which were significantly decreased.

Conclusions: Vitamin D supplementation may be beneficial to diabetic subjects because it improved glycemic control. Diabetic subjects with high 25(OH)D levels (>61 ng/ml) had better lipid profiles.     

Abstracts on Calcium and Bone Metabolism

Objective: Vitamin D supplementation may be required for certain subgroups in the United States in whom status and intake are inadequate, but the impact of various doses, and whether calcium administration jointly or independently influences vitamin D metabolite levels, is unclear.

Methods: In a pilot chemoprevention trial of biomarkers of risk for colorectal adenoma, we measured the impact of vitamin D supplementation and/or calcium supplementation on plasma vitamin D metabolite concentrations. Ninety-two adult men and women living in the southeastern United States were randomized to 800 IU vitamin D₃, 2000 mg elemental calcium, both, or placebo daily for 6 months. We examined vitamin D status at baseline and postintervention and compared the change in plasma 25-hydroxyvitamin D (25(OH)D) and 1,25(OH)₂D levels by intervention group using general linear models.

Results: Eighty-two percent of the study population had insufficient plasma 25(OH)D concentrations (<75 nmol/L) at baseline, with the lowest levels observed among African American participants. Vitamin D supplements, with or without calcium supplementation, raised plasma 25(OH)D concentrations, on average, by 25 to 26 nmol/L. Half of the study participants were classified as having sufficient 25(OH)D status after 6 months of 800 IU of vitamin D₃ daily. Calcium alone did not influence 25(OH)D concentrations.

Conclusion: In this southeastern U.S. population, half of the study participants receiving 800 IU vitamin D₃ daily had blood 25(OH)D concentrations of ≤75 nmol/L after a 6-month intervention period, supporting higher vitamin D dose requirements estimated by some groups. More research is needed to identify the optimal vitamin D dose to improve 25(OH)D status in various at-risk populations.     

More on the zinc connection.

Background: Inadequate vitamin D nutritional status is increasingly recognized as common in North American and European populations, but the extent of the shortfall and the parameters of the distribution for populations of interest remain uncertain.

Purpose: To report the distribution of values for serum 25-hydroxyvitamin D [25(OH)D] in a population of rural postmenopausal women, together with quantification of factors related to vitamin D status.

Setting: Nine largely agrarian counties in eastern Nebraska (～41° N).

Participants: A population-based sample of 1,179 women 55 years of age and older recruited into a four-year trial of calcium and vitamin D supplementation.

Methods: Baseline biochemical, dietary, and anthropometric measurements obtained on entry into trial.

Results: Serum 25(OH)D concentration at baseline varied cyclically with season, with the solar cycle explaining 2.9% of the total variance (P < 0.001). Mean seasonally adjusted 25(OH)D concentration was 71.1 nmol/L. Serum 25(OH)D also exhibited the expected inverse curvilinear relationship with serum parathyroid hormone (PTH), with the inflection point of the curve located at approximately 80 nmol/L. Supplements containing vitamin D were regularly taken by 59% of the cohort (median dose: 200 IU/d). Nevertheless, approximately 4% of all women had values below the laboratory reference range and more than two-thirds fell below 80 nmol/L. Seasonally adjusted serum 25(OH)D concentration was positively correlated with the size of daily vitamin D supplement dose, and negatively with age, weight, and body mass index (P < 0.01 for all). In stepwise multiple linear regression models, weight, age, and supplement dose were independently correlated with seasonally adjusted serum 25(OH)D, and together explained 19% of the total variance of adjusted 25(OH)D concentration. Women taking supplements had only one-sixth the chance of having a 25(OH)D value below the reference limit of the assay, compared to women who did not use supplements.

Conclusions: Approximately two-thirds of this rural population fell below 80 nmol/L, a value considered to be the lower end of the optimal range. Based on the slope of 25(OH)D on supplement dose observed in these women, it would require an additional vitamin D input of nearly 2000 IU/d to reach the goal of an RDA for vitamin D, i.e., to bring 97.5% of the cohort to levels of 80 nmol/L or higher.     

Vitamin D Supplementation on Carotid Remodeling and Stiffness in Obese Adolescents

Obesity is associated with vitamin D (VD) deficiency and arterial stiffness. This randomized control trial assessed the effects of VD supplementation during a weight-loss program on carotid intima-media thickness (IMT) and carotid compliance in obese adolescents. Participants were randomly assigned to receive either a 12-week lifestyle program with VD supplementation (n = 13), a lifestyle program without VD supplementation (n = 13) or a control group composed of normal-weight adolescents (n = 18). Serum total and free 25-hydroxyvitamin D (25(OH)D), IMT and carotid compliance were measured before and after the trial. Insufficiency in 25(OH)D concentration was found in 73% of obese participants compared to 22% among controls. Obese adolescents had lower free 25(OH)D and displayed higher IMT but lower carotid compliance than controls. Free 25(OH)D and IMT were negatively correlated in adolescents displaying VD insufficiency at baseline. After three months, total and free 25(OH)D increased in both groups. The changes of IMT and carotid compliance were similar between groups. The changes in IMT were correlated with the changes in total 25(OH)D in obese adolescents with VD insufficiency at baseline (r = −0.59, p = 0.03). While the lifestyle program with VD supplementation did not affect carotid compliance, IMT reduction was improved in obese adolescents.     

Calcium and Vitamin D Disparities Are Related to Gender,Age, Race,Household Income Level,and Weight Classification but Not Vegetarian Status in the United States: Analysis of the NHANES 2001–2008 Data Set

Objective: Adequate calcium and vitamin D intakes are critical during all life cycle stages. This study aimed to characterize usual intakes of calcium and vitamin D from food and dietary supplements in specific subpopulations of Americans so that fortification/enrichment and supplementation efforts may be targeted toward populations who are truly in need.

Methods: The National Cancer Institute method was used to estimate usual intakes of calcium and vitamin D by source and compared usual intakes to the established Dietary Reference Intakes for U.S. residents aged ≥4 years using National Health and Nutrition Examination Survey 2001–2002, 2003–2004, 2005–2006, and 2007–2008 data sets.

Results: These results showed for the first time that low-income, overweight, and/or obese minority populations may be at greater risk of calcium and vitamin D insufficiency. Children aged 4–8 years were more likely to obtain recommended dairy intakes compared with older children and adults of all ages. Food intakes of calcium decreased with age in adults. Adults who used supplemental calcium showed a lower prevalence of insufficiency. Calcium and vitamin D intakes from food and dietary supplements were not related to vegetarian status. Excessive intakes of calcium and vitamin D above the tolerable upper intake level were low among all studied populations and “overnutrification” was not widely present across these analyses.

Conclusions: Age- and gender-specific supplementation and modest use of fortification with calcium and vitamin D may be warranted for targeting certain subpopulations, particularly older adults, teenagers, minorities, and those who are low income and overweight and/or obese.

Practical Application: This study aimed to characterize usual intakes of calcium and vitamin D from food and dietary supplements in specific subpopulations of Americans so that fortification/enrichment and supplementation efforts may be better targeted. Low-income, overweight, and/or obese minority populations may be at a greater risk of calcium and vitamin D insufficiency.     

Importance of vitamin D in hospital-based fracture care pathways

Objectives: This project was developed to identify ways to support hospital-based improvements for the identification and management of osteoporosis following treament of a fragility fracture.Design: This is a retrospective review of medical records of sets of consecutive patients who were admitted for surgical treatment of fragility fracture following introduction of several versions of admission and discharge care pathways. Effectiveness of the admission pathway was defined as % subjects with measurement of serum 25-hydroxyvitamin D (25(OH)D) during hospitalization; effectiveness of the discharge pathway was defined as % subjects with documentation of instructions for calcium and/or vitamin D supplementation.Setting: This study reviewed medical records of patients admitted to hospital for surgical treatment of a fragility fracture.Participants: Medical records were evaluated for 98 patients older than 50-years who were admitted with a fragility fracture of the hip or femur.Measurements: Medical records were reviewed for the % subjects with documentation of an in-hospital order for serum 25(OH)D and with documentation of instructions to patients upon discharge concerning calcium and vitamin D intake. Median value of serum 25(OH)D was calculated.Results: In accordance with the admission pathway, serum 25(OH)D was measured in 37% (36/98). The median 25(OH)D level was 19.5 ng/mL; 78% were vitamin D insufficient [serum 25(OH)D≤ 32 ng/mL] and 58% were vitamin D deficient [serum 25(OH)D ≤20 ng/mL]. In accordance with the discharge pathway, 74% (71/96) were discharged on calcium and/or vitamin D.Conclusion: The high prevalence of vitamin D insufficiency (78%) observed in this study affirms the importance of incorporating vitamin D supplementation in hospital-based fracture care pathways. The discharge pathway was more effective than the newer admission pathway, a finding attributable to effects of familiarity, retraining, and introduction of computer-prompts. These evolving pathways represent a much-needed paradigm shift in the care of fragility fracture patients.     

Single high-dose vitamin D at birth corrects vitamin D deficiency in infants in Mexico

Abstract

This study examined the prevalence of vitamin D deficiency in mothers and infants in Tijuana, Mexico and determined the effect of a single oral dose of 50?000?IU vitamin D₃ at birth on 25-hydroxyvitamin D (25[OH]D) levels during infancy. Healthy infants were randomized to receive vitamin D₃ or placebo at birth. At birth 23% of infants were vitamin D deficient and 77% had vitamin D insufficiency (mean 25[OH]D level 18.9?ng/ml); 10% of mothers were vitamin D deficient and 61% were insufficient. Infants receiving vitamin D₃ had higher 25(OH)D levels at two months (N?=?29; 33.9 versus 24.2?ng/ml) and six months (N?=?21; 36.5 versus 27.4?ng/ml). Exclusively breastfed infants had lower 25(OH)D levels at two months (14.9 versus 33.4?ng/ml). Vitamin D deficiency is common in infants and mothers in Tijuana, Mexico. A single dose of vitamin D₃ at birth was safe and significantly increased 25(OH)D levels during infancy.     

Vitamin D,Vitamin D-Binding Proteins,and VDR Polymorphisms in Individuals with Hyperglycaemia

Vitamin D reportedly plays an important role in the pathogenesis of diabetes mellitus; however, this role is unclear and debated. This study investigated the association between 25(OH) vitamin D, vitamin D-binding proteins, and vitamin D receptor (VDR) polymorphisms in healthy individuals and those with prediabetes and type 2 diabetes mellitus (T2D) from South Africa. A cross-sectional study was conducted involving subjects of mixed ancestry aged ≥20 years. Males presented with higher mean 25(OH) vitamin D levels than females, while females exhibited significantly higher serum vitamin D-binding protein levels. Significant differences in mean 25(OH) vitamin D levels were observed in normo-glycaemic, prediabetes, screen-detected DM, and known DM individuals. Vitamin D receptor SNPs Fok1 and Taq1 were not associated with glycaemic status. Fok1 was not associated with 25(OH) vitamin D deficiency, while Taq1 was associated with vitamin D insufficiency. This study showed a high prevalence of vitamin D deficiency/insufficiency in this South African population, with decreased vitamin D levels observed in hyperglycaemic individuals, which was not linked to either vitamin D-binding protein or polymorphisms in Fok1 of the VDR gene. These results may be used as a platform for further research into diagnosis and treatment of hyperglycaemia.     

A Randomized Clinical Trial of Vitamin D Supplementation in Healthy Adolescents

PurposeThe most safe and effective dose of vitamin D supplementation for healthy adolescents is currently unknown. The aim of this study was to compare the efficacy of 200 IU versus 1,000 IU of daily vitamin D₃ for supplementation in healthy adolescents with baseline vitamin D sufficiency.MethodsWe conducted a double-blind, randomized clinical trial. Fifty-six subjects, ages 11–19 years, with baseline vitamin D sufficiency received 1,000 IU or 200 IU of daily vitamin D₃ for 11 weeks. Compliance was assessed using MEMS6 Trackcaps and pill counts.ResultsFifty-three subjects completed the clinical trial. Subjects in the two treatment arms were similar in terms of age, race, gender, body mass index, and dietary calcium and vitamin D intake. Serum 25(OH)D level in the 200 IU treatment arm was 28.1 ± 6.2 ng/mL at baseline (mean ± SD) and 28.9 ± 7.0 ng/mL at follow-up. In the 1,000 IU treatment arm, 25(OH)D levels were 29.0 ± 7.3 and 30.1 ± 6.6 at baseline and follow-up, respectively. Mean change in 25(OH)D level did not differ significantly between treatment arms (p = .87), nor did mean change in parathyroid hormone, calcium, phosphate, bone turnover markers, fasting glucose, or fasting insulin.ConclusionsIn healthy adolescents with baseline vitamin D sufficiency, supplementation with vitamin D₃ doses of 200 and 1,000 IU for 11 weeks did not increase serum 25(OH)D levels, with no significant difference observed between treatment arms.     

Vitamin D Deficiency in Cord Plasma from Multiethnic Subjects Living in the Tropics

Background: Vitamin D deficiency is commonly reported in high-latitude areas and in dark-pigmented individuals. However, nothing is known about vitamin D in cord blood from multiethnic subjects living in the tropics.

Objective: Our study objective was to determine the prevalence of vitamin D deficiency in summer and winter in cord blood from multiethnic individuals in Hawai’i where sufficient sun irradiance occurs year-round for cutaneous vitamin D production.

Methods: 25-Hydroxyvitamin D (25(OH)D) levels were quantified by enzyme immunoassay in 100 cord plasma samples from apparently healthy full-term newborns and their mothers. Stratification was performed by birth season and ethnicity.

Results: Mean 25(OH)D levels were 24.5 ng/mL (9.1–68.3 ng/mL). Overall, 28% of samples were vitamin D deficient (<20 ng/mL) and 50% were insufficient (20–30 ng/mL). 25(OH)D levels (ng/mL) were highest in Caucasians (30.5, n = 19), followed by Asians (25.1, n = 43), Hispanics (21.5, n = 3), Pacific Islanders (20.0, n = 25), and African Americans (19.6, n = 2). Differences among groups were significant (p = 0.008). Cord plasmas from summer versus winter were higher overall (p = 0.001) and among Asians (p = 0.0003). Seasonal changes were correlated with sun irradiance overall (r = 0.43, p = 0.0001), among Caucasians (r = 0.45, p = 0.05), and among Asians (r = 0.45, p = 0.0001).

Conclusion: Our results suggest that prenatal supplement recommendations of 400 IU vitamin D/day do not protect against vitamin D deficiency, even in subjects living in the tropics where ample sun irradiance exists for cutaneous vitamin D synthesis. The high prevalence of vitamin D deficiency we observed emphasizes the necessity for regular 25(OH)D monitoring, particularly during pregnancy and lactation, in dark-pigmented individuals, and during winter months.     

Factors Affecting 25-Hydroxyvitamin D Concentration in Response to Vitamin D Supplementation

Sun exposure is the main source of vitamin D. Due to many lifestyle risk factors vitamin D deficiency/insufficiency is becoming a worldwide health problem. Low 25(OH)D concentration is associated with adverse musculoskeletal and non-musculoskeletal health outcomes. Vitamin D supplementation is currently the best approach to treat deficiency and to maintain adequacy. In response to a given dose of vitamin D, the effect on 25(OH)D concentration differs between individuals, and it is imperative that factors affecting this response be identified. For this review, a comprehensive literature search was conducted to identify those factors and to explore their significance in relation to circulating 25(OH)D response to vitamin D supplementation. The effect of several demographic/biological factors such as baseline 25(OH)D, aging, body mass index(BMI)/body fat percentage, ethnicity, calcium intake, genetics, oestrogen use, dietary fat content and composition, and some diseases and medications has been addressed. Furthermore, strategies employed by researchers or health care providers (type, dose and duration of vitamin D supplementation) and environment (season) are other contributing factors. With the exception of baseline 25(OH)D, BMI/body fat percentage, dose and type of vitamin D, the relative importance of other factors and the mechanisms by which these factors may affect the response remains to be determined.     

Cholecalciferol significantly increases 25-hydroxyvitamin D concentrations in adults with cystic fibrosis

BACKGROUND: Vitamin D deficiency is increasingly being recognized and treated in patients with cystic fibrosis, although the treatment guidelines are not proven and the effectiveness of vitamin D preparations is untested. OBJECTIVES: The aims of this study were to determine the prevalence of 25-hydroxyvitamin D [25(OH)D] deficiency in a large cohort of adults with cystic fibrosis and to evaluate the effectiveness of supplementation with cholecalciferol. DESIGN: In this retrospective cohort design, baseline 25(OH)D concentrations were measured, and the effects of clinical interventions that involved either counseling on compliance or increasing supplemental cholecalciferol on serum 25(OH)D concentrations in those subjects with baseline concentrations 相似文献   

Vitamin D Intake May Reduce SARS-CoV-2 Infection Morbidity in Health Care Workers

In the last 2 years, observational studies have shown that a low 25-hydroxyvitamin D (25(OH)D) level affected the severity of infection with the novel coronavirus (COVID-19). This study aimed to analyze the potential effect of vitamin D supplementation in reducing SARS-CoV-2 infection morbidity and severity in health care workers. Of 128 health care workers, 91 (consisting of 38 medical doctors (42%), 38 nurses (42%), and 15 medical attendants (16%)) were randomized into two groups receiving vitamin D supplementation. Participants of group I (n = 45) received water-soluble cholecalciferol at a dose of 50,000 IU/week for 2 consecutive weeks, followed by 5000 IU/day for the rest of the study. Participants of group II (n = 46) received water-soluble cholecalciferol at a dose of 2000 IU/day. For both groups, treatment lasted 3 months. Baseline serum 25(OH)D level in health care workers varied from 3.0 to 65.1 ng/mL (median, 17.7 (interquartile range, 12.2; 24.7) ng/mL). Vitamin D deficiency, insufficiency, and normal vitamin D status were diagnosed in 60%, 30%, and 10%, respectively. Only 78 subjects completed the study. Vitamin D supplementation was associated with an increase in serum 25(OH)D level, but only intake of 5000 IU/day was accompanied by normalization of serum 25(OH)D level, which occurred in 53% of cases. Neither vitamin D intake nor vitamin D deficiency/insufficiency were associated with a decrease in SARS-CoV-2 morbidity (odds ratio = 2.27; 95% confidence interval, 0.72 to 7.12). However, subjects receiving high-dose vitamin D had only asymptomatic SARS-CoV-2 in 10 (26%) cases; at the same time, participants who received 2000 IU/day showed twice as many SARS-CoV-2 cases, with mild clinical features in half of them.     

Perinatal Vitamin D and Calcium Status of Northern Canadian Mothers and Their Newborn Infants

Objective: This study was undertaken to examine the vitamin D and calcium status of mothers and their newborns.

Methods: The intakes of vitamin D and calcium were determined prenatally in 121 women including 33 Caucasians, 51 Inuits, and 37 Native Indians, living in the Inuvik zone of the Northwest Territories. Plasma concentrations of 25-(OH)-D and calcium were also measured in mothers as well as in their offspring at delivery.

Results: The daily mean vitamin D intake of native mothers, including Inuits and Indians, with (8.1±5.5 μg) and without supplements (3.4±2.5 μg) was significantly lower than that of non-native mothers (13.2±5.9 μg and 5.8±4.3 μg, respectively). According to the predicted prevalence of low vitamin D intake, there existed a higher risk of vitamin D deficiency without supplementation in both native (88.6% vs 48.4%) and non-native (63.5% vs. 15.1%) mothers. The trend for calcium intakes with and without supplementation was similar to vitamin D intake. At the point of delivery, the plasma levels of 25-(OH)-D were lower in native mothers (50.1±19.3 nmol/L) and their offspring (34.2±13.1 nmol/L) than their counterparts (59.8±29.4 nmol/L and 41.4±23.5 nmol/L, respectively). Its plasma levels in newborn infants averaged only 67% of their mothers. None of these infants showed clinical evidence of vitamin D deficiency. In fact, their plasma calcium levels were significantly higher than their mothers.

Conclusions: Plasma 25-(OH)-D concentrations of 60 to 70% of maternal levels may represent a “normal” range for newborn infants. However, a supplementation in native northern Canadian mothers during pregnancy and in their neonates during infancy may have a role to play in the prevention of vitamin D deficiency.     

Vitamin D Deficiency and Insufficiency in the Georgia Older Americans Nutrition Program

ABSTRACT

Serum 25-hydroxyvitamin D (25(OH)D) status in older adults enrolled in community-based meal programs is not well characterized. The objective was to identify predictors of poor serum 25(OH)D status and the response to vitamin D supplementation in a convenience sample from the Older Americans Act Nutrition Program (OAANP) in northeast Georgia (N = 158, mean age = 77 years, 81% women, 69% Caucasian, 31% African American). Mean serum 25(OH)D was 55 nmol/l, and intakes of vitamin D and calcium from foods were very low. Vitamin D insufficiency (25(OH)D 25- < 50 nmol/l) occurred in 36.7%. Vitamin D deficiency occurred in 8.2% (25(OH)D < 25 nmol/l) and was associated with low milk intake, low sunlight exposure, receiving meals at home, tobacco use, depression, dementia, antianxiety medication, poor instrumental activities of daily living, and low calf circumference (p ≤ 0.05). When non-supplement users (n = 28) were given a multivitamin with vitamin D (10 µg/d) and calcium (450 mg/d) for 4 months, 25(OH)D increased from 50 to 78 nmol/l, the prevalence of poor vitamin D status (25(OH)D < 50 nmol/l) decreased from 61% to 14%, and serum alkaline phosphatase decreased by 10% (p < 0.01). High body weight appeared to attenuate the increase in 25(OH)D in response to the multivitamin supplement (p ≤ 0.05). In conclusion, OAANP services did not prevent poor vitamin D and calcium status, but a supplement with vitamin D and calcium was beneficial.     

Vitamin D insufficiency in children, adolescents, and young adults with cystic fibrosis despite routine oral supplementation

BACKGROUND: Cystic fibrosis (CF) with pancreatic insufficiency is associated with poor absorption of fat and fat-soluble vitamins, including vitamin D. Pancreatic enzyme supplementation does not completely correct fat malabsorption in CF patients. OBJECTIVE: The objective of the study was to compare the vitamin D status of children, adolescents, and young adults with CF who were treated with routine vitamin D and pancreatic enzyme supplements with the vitamin D status of a healthy reference group from a similar geographic area. DESIGN: Growth, dietary intake, and serum concentrations of 25-hydroxyvitamin D [25(OH)D], 1,25-dihydroxyvitamin D [1,25(OH)(2)D], and parathyroid hormone (PTH) were measured in 101 white subjects with CF and a reference group of 177 white subjects. RESULTS: The median daily vitamin D supplementation in the CF group was 800 IU. The mean +/- SD serum concentrations of 25(OH)D were 20.7 +/- 6.5 ng/mL in the CF group and 26.2 +/- 8.6 ng/mL in the reference group (P < 0.001). Vitamin D deficiency and insufficiency were defined as 25(OH)D concentrations < 11 ng/mL and < 30 ng/mL, respectively. Seven percent of the CF group and 2% of the healthy reference group were vitamin D deficient (P < 0.03). Ninety percent of the CF group and 74% of the healthy reference group were vitamin D insufficient (P < 0.01). Twenty-five percent of the CF group and 9% of the healthy reference group had elevated PTH (P < 0.006). The odds of vitamin D insufficiency in the CF group, compared with the healthy reference group, were 1.2 (95% CI: 1.1, 1.3) after adjustment for season and age. CONCLUSION: Despite daily vitamin D supplementation, serum 25(OH)D concentrations remain low in children, adolescents, and young adults with CF.     

Effect of a Nutritional Supplementation on Bone Health in Chilean Elderly Subjects with Femoral Osteoporosis

Objective: To study the effects of a special nutritional supplement on bone mineral density and bone turnover markers in Chilean elderly subjects with femoral osteoporosis.

Setting: Public primary health care clinics in Chile.

Subjects: Free living elderly subjects with femoral osteoporosis.

Interventions: Subjects were randomized to receive the usual nutritional supplement provided by the Chilean Ministry of Health or a special nutritional supplement providing, among other nutrients, 90 mg isoflavones, 800 mg calcium, 400 IU vitamin D, 60 ug vitamin K and 31 g proteins per day.

Measures of Outcome: At baseline, and after six and twelve months of supplementation, body composition, bone mineral density, serum 25 OH vitamin D, intact parathyroid hormone (iPTH), osteocalcin, decarboxylated osteocalcin, urinary aminoterminal telopeptide of type I collagen (NTX), deoxypyridoline cross links (Dpd) and equol were measured. Every month, urinary daidzein was measured in a morning urine sample.

Results: No differences between treatment groups were observed in body composition or bone mineral density changes. The group receiving the special supplement had a significant increase in serum 25 OH vitamin D and a significant decrease in serum iPTH and decarboxylated osteocalcin. No association between daidzein or equol excretion and changes in bone mineralization was observed.

Conclusions: A special supplement delivered to elderly subjects with osteoporosis improved serum vitamin D and reduced serum iPTH and undercarboxylated osteocalcin levels but did not affect BMD.     

Effect of Five-Year Supplementation of Vitamin C on Serum Vitamin C Concentration and Consumption of Vegetables and Fruits in Middle-Aged Japanese: A Randomized Controlled Trial

Objective: This study was aimed at evaluating the effect of long-term vitamin C supplementation on serum and dietary vitamin C and identifying the factors associated with change in serum concentration.

Methods: A total of 439 subjects with atrophic gastritis initially participated in a randomized clinical trial using vitamin C and β-carotene to prevent gastric cancer. We originally randomized the participants into four treatment groups using a 2×2 factorial design, whereby 0 or 15 mg/day β-carotene and 50 or 500 mg/day vitamin C were administered in a double-blind manner. The β-carotene component was terminated early after a mean treatment duration of four months. Before and upon early termination of β-carotene supplementation, 134 subjects dropped out this trial, while 120 and 124 subjects took the vitamin C supplement at either 50 mg or 500 mg daily for five years.

Results: Changes in serum vitamin C were significantly higher in the high-dose group (38.5% increase, 95% CI = 27.0–49.9) than in the low-dose group (13.0% increase, 5.1–20.9) or in the dropout group (3.3% increase, ?2.1–8.6) after five-year supplementation. The serum vitamin C at baseline was negatively associated with changes in serum vitamin C (p < 0.0001), while high-dose (p < 0.0001) and low-dose (p < 0.05) supplementation and female gender (p < 0.001) were positively associated. Dietary intake of vitamin C in the supplementation group was almost identical before and after five-year supplementation of vitamin C (2.31 mg/day decrease, 95% CI = ?15.3–10.7), while a 17.7 mg/day decrease (95% CI = ?44.2–8.86) was observed in the drop-out group.

Conclusion: Five-year vitamin C supplementation induces a remarkable increase in serum vitamin C concentration, and our intervention program appears to have no effect on dietary vitamin C intake.     

25(OH)D Levels in Relation to Gender,Overweight, Insulin Resistance,and Inflammation in a Cross-Sectional Cohort of Northern Italian Workers: Evidence in Support of Preventive Health Care Programs

Objective: In recent years, the welfare of workers and the prevention of chronic disabling diseases has become a topic of great interest. This study investigates serum levels of total 25-hydroxyvitamin D (25(OH)D) in a cohort of overweight–obese and insulin-resistant northern Italian indoor workers in apparent good health followed a nutritional education program.

Methods: An observational cross-sectional study on 385 patients (females = 291, males = 94), age range 18–69 years and body mass index (BMI) > 25 kg/m², was performed at the Department of Occupational Medicine Milan, Italy, latitude 45.465454 N. We evaluated nutritional intakes, occupational and leisure physical activity, anthropometric measurements, impedance evaluation, blood pressure, the presence of metabolic syndrome (MetS) and nonalcoholic fatty liver diseases (NAFLD) by fatty liver index (FLI). Hematologic and biochemical parameters and (25(OH)D) levels were evaluated from fasting blood samples.

Results: Only 10.91% of subjects had optimal values of 25(OH)D; 17.40% of the remaining 89.09% subjects were severely deficient, with no gender difference and insufficient intake of vitamin D. Only 28% declared leisure physical activity; 39.48% had metabolic syndrome and 62.60% had an FLI > 30. An inverse relationship between 25(OH)D levels and BMI was found, with a significant reduction of total 25(OH)D serum concentrations in winter. The homeostasis model assessment–insulin resistance (HOMA-IR) is positively related to BMI and inversely related to 25(OH)D concentrations. A positive correlation between vitamin D and leisure physical activity was found. At univariate analysis adjusted for age, gender and BMI, an inverse relationship between vitamin D and FLI was observed in both genders. The correlation between 25(OH)D levels, inflammation markers, BMI, and FLI showed an increased risk of cardiovascular disease in this cohort of workers.

Conclusion: Our results suggest the rationale for a large-scale screening program for vitamin D by means of easily implementable low-cost preventive supplementation.