Effects of Vitamin D3 and Calcium Supplementation on Serum Levels of Tocopherols,Retinol, and Specific Vitamin D Metabolites

γ-Tocopherol (γT) protects against DNA-damaging effects of nitrogen oxides, yet its physiologic regulation in vivo is unknown. Observational studies indicate inverse associations of 25[OH]-vitamin D with γT and leptin. To determine whether vitamin D₃ supplementation alters levels of lipid-soluble micronutrients, serum samples (N = 85 subjects) from a randomized, double-blind, placebo-controlled clinical trial of vitamin D₃ (800 IU) and calcium (2 g), alone and in combination, were analyzed for lipid micronutrients and specific vitamin D metabolites at baseline and after 6 mo of supplementation. Serum 25[OH]-vitaminD₃ levels increased 55% (P < 0.0001) and 48% (P = 0.0005), whereas 25[OH]-vitaminD₂ levels were lower by 48% (P = 0.26) and 21% (P = 0.36) in the vitamin D₃ and vitamin D₃ plus calcium groups, respectively. At baseline, γT levels were inversely associated with 25[OH]D (r = ?0.31, P = 0.004). With vitamin D₃ plus calcium treatment, serum α-tocopherol decreased 14% (P = 0.04), whereas similar changes in γT (19% lower, P = 0.14) were observed. No significant effects were observed for D₃ supplementation on leptin or retinol levels. These results are consistent with the hypothesis that vitamin D₃ ± calcium affects serum tocopherol and 25[OH]D₂ levels; however, studies using larger, more homogeneous populations are warranted.     

Serum 25-hydroxyvitamin D, dietary calcium intake, and distal colorectal adenoma risk

Vitamin D has recently emerged as a potentially protective agent against colorectal neoplasia. We assessed the associations between dietary vitamin D, plasma 25-hydroxyvitamin D [25(OH)D], dietary calcium, and colorectal adenomas in a large screening sigmoidoscopy-based case-control study in Southern California. Because conversion of serum 25(OH)D to serum 1,25-vitamin D is highly regulated by serum calcium, we also assessed modification of the 25(OH)D-adenoma association by calcium intake. Cases were 473 subjects with a primary adenoma, and controls were 507 subjects who had no adenomas at sigmoidoscopy and no history of adenomas. Compared with those in the lowest quartile of intake, those in the highest quartile of dietary vitamin D had an adjusted odds ratio (OR) of 0.83 [95% confidence interval (CI) = 0.49-1.41] and those in the highest quartile of dietary calcium had an OR of 0.82 (95% CI = 0.49-1.25). There was a suggestion that plasma 25(OH)D may be protective in this population (OR for highest vs. lowest quartile = 0.74, 95% CI = 0.51-1.09). A significant protective effect of 25(OH)D was clearly evident only in those with calcium intakes below (OR = 0.40 for highest vs. lowest quartile, 95% CI = 0.22-0.71, p for trend = 0.005) and above (OR = 1.17, 95% CI = 0.69-1.99, p for trend = 0.94) the median calcium intake.     

High prevalence of low dietary calcium and low vitamin D status in healthy south Indians

Calcium and vitamin D under nutrition can adversely affect the bone mineral metabolism. There is no population-based study from India documenting dietary habits, serum calcium and vitamin D levels. Our study investigated the dietary habits of rural and urban societies in and around Tirupati and their relationship with serum calcium, phosphorous and vitamin D [25(OH)D] levels. Four hundred and seven subjects from 5 villages around Tirupati, (rural population) and 125 asymptomatic staff of our hospital (urban population) were studied. Dietary intakes of calcium, phosphorous and phytates were documented by diet history. Serum calcium, phosphorus and 25 (OH) D levels were estimated in 191 rural subjects and 125 urban subjects. Compared to urban subjects, rural subjects had a significantly lower intake of dietary calcium (P <0.0001) and a significantly higher dietary phytate/calcium ratio and serum calcium and 25 (OH) D levels (P <0.0001). Dietary calcium intake was inadequate in both rural and urban subjects compared to the recommended daily allowances (RDA) for our country. About 31% of the population had normal vitamin D levels, 54% had vitamin D insufficiency and 15% vitamin D deficiency. About two-thirds of the population had low levels of vitamin D. Inadequate dietary calcium intake associated with high phytate/calcium ratio reduces the bioavailable calcium in the gut. Hence, there is a need to fortify food with calcium and to propose new guidelines for 25 (OH) D in Indian subjects. Multicentric studies with large sample populations are required to generate normal standards and nationally relevant guidelines.     

补充钙及维生素D对2～3岁幼儿身长的影响

目的 分析钙与维生素D(VitD)的营养情况与2～3岁幼儿身长发育的相关性,为体格发育偏离干预提供一定理论依据。方法 回顾性分析在2019年9月—2021年6月西北妇女儿童医院儿童保健科常规体检的204例幼儿(年龄2～3岁)的临床资料。对这些幼儿进行标准体格测量和对其既往钙和维生素D的补充情况以问卷形式进行回顾性调查,同时检测儿童的血清25-(OH)D和骨密度。对体格发育情况与钙和VitD的营养状况采用了Spearman相关及Logistic多因素回归分析等方法进行统计学分析。结果 每日平均补充VitD剂量的中位数为569.5 U,204例幼儿血清25-(OH)D的中位数为35.60 ng/dl。VitD缺乏检出率1.96%、不足检出率0.98%、充足检出率97.06%,无VitD过量;骨密度中位数为P64.0;单因素Spearman秩相关分析显示,每日平均补充VitD的剂量和每日平均补充钙剂量均与身长呈正相关(r=0.172、0.213,P<0.05);骨密度与身长呈负相关(r=-0.138,P<0.05);多因素Logistics回归分析显示,每日平均补充钙剂量与身长呈...     

Effects of vitamin D supplementation on 25-hydroxyvitamin D, high-density lipoprotein cholesterol, and other cardiovascular disease risk markers in subjects with elevated waist circumference

The objective of the present trial was to assess the effects of vitamin D supplementation on serum 25-hydroxyvitamin D [25(OH)D] and high-density lipoprotein cholesterol (HDL-C) in subjects with high waist circumference. Subjects were randomly assigned a daily multivitamin and mineral (MVM) supplement or a MVM supplement plus vitamin D 1,200 IU/day (MVM+D) for 8 weeks. There was a significant difference in mean change for 25(OH)D between the MVM and MVM+D treatment groups ( - 1.2 ± 2.5 nmol/l vs. 11.7 ± 3.0 nmol/l, respectively; P = 0.003). Vitamin D 1,200 IU/day did not increase 25(OH)D to a desirable level ( ≥ 75 nmol/l) in 61% of participants. There were no significant changes in cardiovascular disease risk markers. Thus, vitamin D supplementation with 1,200 IU/day was insufficient to achieve desirable serum 25(OH)D in most participants and did not affect cardiovascular disease risk markers.     

无锡市足月新生儿维生素D水平及适宜补充剂量的研究

目的 分析无锡市新生儿维生素D(VD)的营养状况及其影响因素,为制定适合本地区的新生儿VD补充方案提供科学依据。方法 选取2015年3月-2018年3月入住无锡市人民医院新生儿科的足月、母乳喂养、日龄≤7 d的新生儿347例,检测其血清25-(OH)D基础水平,其中血清25-(OH)D≤50 nmol/L的新生儿随机分为两组,分别给予400 U/d或800 U/d VD口服,6周后复查。同时对其母亲一般信息及孕期补充VD情况等展开问卷调查。结果 VD缺乏、VD不足和VD充足的比例分别为91.07%、8.07%和0.86%。夏秋季出生的患儿血清25-(OH)D水平较冬春季出生的患儿高(t=-3.467,P<0.05)。6周后复查发现,总体患儿血清25-(OH)D平均值较前上升,VD缺乏者比例下降(χ²=118.235、163.196,P＜0.05)。 新生儿血清25-(OH)D水平与母亲孕期是否补充充足的钙剂、VD存在一定的相关性(r=0.116,P=0.043)。结论 无锡地区足月新生儿VD普遍缺乏,建议根据母亲孕期VD补充情况,可以将早期足月新生儿VD补充剂量调整为400~800 U/d,持续6周。     

泸州市儿童血清25－羟维生素 D 水平调查分析

目的：调查暑期儿童血清25－羟维生素D[25（OH）D]水平,为合理补充维生素D提供科学依据。方法选取2015年7-8月间在泸州医学院附属医院儿童保健科门诊常规体检的1～16岁儿童670名为研究对象,采用化学发光法检测儿童血清25（OH）D,以体质量指数（BMI）将研究对象分为肥胖组、超重组及正常组。结果儿童25（OH）D总体水平为28．48±10．40 ng／mL,缺乏及不足率高达60．30％,＞7～16岁组、1～3岁组及＞3～7岁组儿童25（OH）D水平差异具有统计学意义,其中1～3岁组最高,＞7～16岁组最低,组间比较有统计学意义（F＝77．218,P＜0．05）。肥胖组、超重组儿童25（OH）D水平缺乏率明显高于正常儿童组（χ2值分别为6．94、7．12,均P＜0．05）;城区儿童25（OH）D水平明显低于农村儿童（t＝－9．128,P＜0．05）。 BMI与25（OH）D呈负相关（r＝－0．242,P＜0．05）。结论泸州市儿童血清25（OH）D总体不足;儿童BMI与25－羟维生素D呈负相关;城区儿童血清25（OH）D总体水平偏低。应加强血清25（OH）D检测,尤其肥胖儿童及城区居住儿童,积极予以合理的维生素D补充并加强对此类儿童的随访观察。     

Determinants of vitamin D status in adult Crohn's disease patients, with particular emphasis on supplemental vitamin D use

OBJECTIVE: To investigate determinants (pathophysiologic and physiologic, behavioural and lifestyle) of vitamin D status in Irish Crohn's disease (CD) patients. DESIGN: A cross-sectional observational study. SETTING: Cork City, Ireland (52 degrees N). SUBJECTS: Crohn's Disease patients (n=58; mean age 38.1 years) were recruited from Cork University Hospital. RESULTS: Fifty and nineteen percent of Irish CD patients were vitamin D deficient (defined by serum 25 hydroxyvitamin (OH) D levels <50 nmol/l) during winter and summer, respectively. Multiple regression analysis showed that summer-time serum 25 (OH) D levels were positively associated with use of vitamin D supplements (P=0.033) and negatively associated with smoking (P=0.006) and being male (P=0.063). During winter-time, use of vitamin D supplements (P=0.041) and sun habits (P=0.066) were positively associated, whereas small intestinal involvement (P=0.005) and body mass index (BMI) (P=0.083) were negatively associated with serum 25 (OH) D levels. There was no significant association between other non-pathophysiologic (age, dietary calcium or vitamin D) or pathophysiologic factors (steroid use, resection), and serum 25 (OH) D levels, at either season. Approximately 41 and 60% of the total variation in summer- and winter-time serum 25 (OH) D, respectively, was explained by this model. CONCLUSION: A high proportion of Irish CD patents had some level of vitamin D deficiency (<50 nmol/l) during late-wintertime. Use of regular low-dose supplemental vitamin D, particularly by patients with small intestinal involvement, cessation of smoking and adequate, but responsible, exposure to summer sunlight as well as maintaining BMI in the normal range could help maintain adequate vitamin D levels during wintertime.     

Vitamin D(3) and vitamin K(1) supplementation of Dutch postmenopausal women with normal and low bone mineral densities: effects on serum 25-hydroxyvitamin D and carboxylated osteocalcin

OBJECTIVE: Improvement of vitamin D and K status of about 60 -y-old postmenopausal Dutch women. DESIGN: In a randomized study postmenopausal women with normal (T-score >-1; n=96) and low (T-score< or =-1; n=45) bone mineral density (BMD) of the lumbar spine, were supplemented with 350-400 IU vitamin D(3), 80 microg vitamins K(1) vitamins K(1)+D(3), or placebo for 1 y. Serum 25-hydroxyvitamin D [25(OH)D] and percentage carboxylated osteocalcin (%carbOC) were measured at baseline and after 3, 6 and 12 months. RESULTS: Baseline %carbOC of the entire study population was positively correlated with BMD of the lumbar spine and femoral neck. Correspondingly, women with low BMD had lower %carbOC at baseline than women with normal BMD but this difference disappeared after 1 y of supplementation with vitamin K(1) ((mean+/-s.d.) 68+/-11% (95% CI, 64. 5-71.2%) vs 72+/-6% (95% CI, 70.1-72.9%), respectively). One year of supplementation with vitamin D(3) showed maximum increases in 25(OH)D of 33+/-29% (95% CI, 24.8-41.8%) and 68+/-58% (95% CI, 50.1-84.6%) in women with normal and low BMD, respectively. During winter, however, a 29% decline in maximum 25(OH)D levels was not prevented in women with low BMD. CONCLUSION: Daily supplementation of Dutch postmenopausal women with >400 IU vitamin D(3) is indicated to prevent a winter decline in 25(OH)D and to control serum parathyroid hormone levels. Daily supplementation with 80 microg vitamin K(1) seems to be necessary to reach premenopausal %carbOC levels. A stimulatory effect of calcium and/or vitamin D on %carbOC cannot be excluded. European Journal of Clinical Nutrition (2000) 54, 626-631.     

Intermittent high-dose vitamin D prophylaxis during infancy: effect on vitamin D metabolites, calcium, and phosphorus

In infants receiving intermittent high dose vitamin D prophylaxis (600,000 IU ergocalciferol per dose orally) every 3-5 mo, the serum concentrations of vitamin D metabolites, calcium (Ca), and phosphorus (P) were determined before and 2 wk after each dose. The 25-hydroxyvitamin D (OHD) concentrations increased to well above normal but the values returned to the normal range before each subsequent dose. The 24,25- and 25,26-dihydroxyvitamin D ([OH]2D) levels followed a pattern similar to that of 25-OHD, and both were closely related to the latter (r = 0.85, p less than 0.005, and r = 0.84, p less than 0.005, respectively). The 1,25-(OH)2D concentrations did not vary in a consistent pattern and remained largely within the normal range. All infants had normal Ca levels before the first dose but 14 infants (34%) later had one or both Ca values above the upper normal limit of 2.80 mmol/L (2.81-3.32 mmol/L), indicating that the vitamin D doses were excessive despite the lack of accumulative increases in serum vitamin D concentrations.     

25-Hydroxyvitamin D and 1,25-dihydroxyvitamin D of D2 and D3 origin in maternal and umbilical cord serum after vitamin D2 supplementation in human pregnancy

Serum concentrations of 25-hydroxyvitamin D (25-OHD) and 1,25-dihydroxyvitamin D [1,25-(OH)2D] of vitamin D2 and D3 origin were determined separately in 10 women before vitamin intake in early pregnancy, and repeated in maternal and cord serum obtained at delivery after 20 to 30 wk of vitamin D2 supplementation in a dose of 400 IU/day. Before supplementation 25-OHD2 and 1,25-(OH)D2D2 were present in just traceable or nondetectable concentrations, but the levels increased in all to a mean +/- 1 SD of 7.3 +/- 3.7 ng/ml and 37.2 +/- 18.1 pg/ml, respectively (p less than 0.0025), by the time of delivery. At delivery the total 25-OHD and 1,25-(OH)2D levels were always lower in the cord than in the maternal serum (30.7 +/- 14.2 versus 20.1 +/- 9.1 ng/ml, and 90.1 +/- 31.2 versus 37.3 +/- 11.6 pg/ml, p less than 0.0025). The paired concentrations of 25-OHD were closely related (r = 0.89, p less than 0.0005), while the association for 1,25-(OH)2D was not statistically significant (r = 0.53, p less than .01). The 25-OHD of D2 and D3 origin accounted for a similar proportion of the total 25-OHD in the maternal and cord serum (ratio of 25-OHD2 to 25-OHD3: 0.40 +/- 0.28 versus 0.45 +/- 0.29, p = NS), as did the respective 1,25-(OH)2D metabolites [ratio of 1,25-(OH)2D2 to 1,25-(OH)2D3: 0.73 +/- 0.35 versus 0.90 +/- 0.50, p = NS].(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

Calcium and vitamin D3 supplements in calcium and vitamin D3 sufficient early postmenopausal healthy women

OBJECTIVE: To study the calcium homeostasis in healthy, calcium and vitamin D replete early postmenopausal women during oral supplementation with calcium and vitamin D3. DESIGN: A prospective, placebo-controlled, randomised, double-single-blind, 3-week study. SETTING: Outpatient clinic at Copenhagen University Hospital, Denmark. SUBJECTS: In all, 17 started, one was excluded. Totally, 16 healthy women, 45-61 y of age (mean 57.3 y) who were at least 4 y after menopause (mean 6.7 y) completed. INTERVENTIONS: All underwent three consecutive 7-day study periods. Each began with 4 days of normal diet followed by 3 days treatment of either C: one tablet of 1.250 mg calcium carbonate (ie 500 mg Ca2+ per tablet) twice daily (breakfast and dinner), or CD3: as in C but plus 400 IU vitamin D3 b.i.d., or P (only) placebo tablets b.i.d. RESULTS: At baseline plasma 25-hydroxycholecalciferol was normal (66+/-22 nmol/l) and the calcium intake without supplements 850 mg/day. In group C, the 24-h urinary calcium increased by 35% (6.9+/-2.0 mmol), vs the placebo group P (5.1+/-1.6 mmol) (P < 0.05). Addition of 800 IU vitamin D3 daily (CD3) did not increase calcium excretion further (6.6+/-2.1 mmol) but decreased plasma 1,25-(OH)2-vitamin D3 by 21% (P < 0.05). CONCLUSIONS: In this carefully controlled study calcium plus vitamin D3 supplements only had minor influences of uncertain significance on the calcium balance in healthy, calcium and vitamin D sufficient early postmenopausal women.     

Bone turnover markers and vitamin D status in postmenopausal Turkish women

The aim of this study was to examine some biochemical markers of bone metabolism such as C-telopeptide of type 1 collagen (CTx), procollagen I N-peptide (PINP), 25 hydroxy vitamin D [25(OH)D], parathormone (PTH), and alkaline phosphatase (total- and bone-ALP) in postmenopausal Turkish women, and to evaluate the influence of dietary factors on these parameters. This cross-sectional study comprised 70 postmenopausal and 25 premenopausal subjects from a similar socio-economical status. The postmenopausal group was further stratified with regard to vitamin plus calcium supplementation. A fasting blood sample was obtained for the biochemical analysis of bone markers. Ca, P, tALP, and CTx levels were significantly higher in postmenopausal women free of supplementation than those in premenopausal period; whereas 25(OH)D concentrations were below the reference value in both groups. Supplementations of vitamin and calcium resulted in significantly lower levels of PINP in the postmenopausal group (p = 0.017). A significant association was found between plasma 25(OH)D level and frequency of fish consumption. Dietary strategies to fortify calcium and vitamin D intake should be considered to decrease the complications due to D hypovitaminosis after the onset of menopause.     

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.     

骨碱性磷酸酶对维生素D缺乏性佝偻病的临床诊断价值探讨

目的:探讨骨碱性磷酸酶(B-ALP)对儿童维生素D缺乏性佝偻病的诊断价值以及血清25-(OH)D与B-ALP的部分影响因素。方法:以551例4月～12岁小儿为研究对象,其中婴幼儿占86.99%。取静脉血测定血清25-(OH)D与B-ALP。结果:①以血清25-(OH)D<50 nmol/L为维生素D(V itD)缺乏的标准,B-ALP>250 U/L时,特异度为69.01%,敏感度为18.12%,阳性似然比为0.58;B-ALP>300 U/L时,特异度为95.91%,敏感度为2.50%,阳性似然比为0.61;②血清25-(OH)D与儿童服用V it D的情况显著相关(r=0.449,P=0.000);③血清25-(OH)D与儿童饮用的奶粉量显著相关(r=0.156,P=0.018);④血清25-(OH)D与B-ALP无相关(r=0.041,P=0.535)。结论:B-ALP诊断儿童维生素D缺乏性佝偻病不能同时满足特异度、灵敏度较高的要求,B-ALP水平越高,特异度越高(误诊率越低),灵敏度越低(漏诊率越高);儿童血清25-(OH)D水平与服用V it D制剂及饮用的奶粉量密切相关。     

2型糖尿病患者血清维生素D水平及相关研究

目的 了解2型糖尿病患者血清维生素D水平的变化,并探讨其在2型糖尿病患者代谢紊乱中的作用及与其他代谢指标的关系.方法 按WHO 1999年关于糖尿病诊断标准筛选初发2型糖尿病患者70例,并按2002年国际肥胖特别工作组亚洲成年人标准,根据体质指数(BMI)分为2型糖尿病A组(BMI≥25.00 kg/m2) 32例和2型糖尿病B组(BMI＜ 25.00 kg/m2)38例,另筛选健康人33例作为对照组,检测人体参数和测量生化指标,用酶联免疫吸附试验法测定血清25羟基维生素D3 [25 (OH)D3]水平,对三组进行比较.结果 2型糖尿病A组血清25 (OH)D3水平为(20.59±4.82)μg/L,2型糖尿病B组为(27.07±5.73) μg/L,对照组为(32.27±8.49)μg/L,三组之间比较差异有统计学意义(P＜0.05).2型糖尿病患者血压正常者43例,血清25(OH)D3水平(25.51±6.12)μg/L,高血压者27例,血清25 (OH)D3水平(21.87±5.78)μg/L,两者比较差异有统计学意义(P＜0.05);2型糖尿病患者血脂正常者8例,血清25(OH)D3水平(28.42±5.20)μg/I,血脂异常者62例,血清25 (OH)D3水平(23.55±6.15)μg/L,两者比较差异有统计学意义(P＜0.05).25(OH)D3与体重、腰围、BMI、收缩压、舒张压、空腹血糖、空腹胰岛素、胰岛素抵抗指数、总胆固醇、三酰甘油、低密度脂蛋白胆固醇呈负相关(P＜0.01或＜0.05),与甲状旁腺素、钙、磷、高密度脂蛋白胆固醇、年龄无明显相关性(P＞0.05).结论 2型糖尿病患者血清维生素D水平降低,尤其是伴有肥胖、高血压、血脂异常者血清维生素D水平降低更明显.     

Efficacy of daily and monthly high-dose calciferol in vitamin D-deficient nulliparous and lactating women

BACKGROUND: We previously found a high prevalence of vitamin D deficiency and low medication regimen compliance in Arab and East Indian women residing in the United Arab Emirates (UAE). The appropriate dosing regimen for improving vitamin D status in this population is not known. OBJECTIVE: We aimed to determine the efficacy of daily and monthly supplementation with vitamin D2, the only high-dose calciferol available in the UAE, in lactating and nulliparous women. DESIGN: Healthy lactating (n = 90) and nulliparous (n = 88) women were randomly assigned to consume 2000 IU vitamin D2/d or 60,000 IU vitamin D2/mo for 3 mo. Serum 25-hydroxyvitamin D [25(OH)D] concentrations were measured by radioimmunoassay at baseline and every month. RESULTS: Most women had vitamin D deficiency [ie, 25(OH)D < 50 nmol/L] at study entry. Mean +/- SD 25(OH)D concentrations at 3 mo were significantly higher than baseline in both lactating (39.8 +/- 12.4 and 25.2 +/- 10.7 nmol/L, respectively) and nulliparous (40.4 +/- 23.4 and 19.3 +/- 12.2 nmol/L, respectively) women (P < 0.001 for both). In total, vitamin D supplementation was effective in achieving serum 25(OH)D concentrations of >or=50 nmol/L in 21 (30%) of 71 women at endpoint. CONCLUSIONS: Oral vitamin D2 supplementation with 2000 IU/d or 60,000 IU/mo for 3 mo was safe, and it increased serum 25(OH)D concentrations significantly; however, only a small proportion of the women studied achieved concentrations of >or=50 nmol/L. This suggests that, when sunlight exposure is limited, doses of vitamin D2 higher than those currently studied may be needed. Monthly dosing appears to be a safe and effective alternative to daily dosing.     

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.     

Canadian Aboriginal women have a higher prevalence of vitamin D deficiency than non-Aboriginal women despite similar dietary vitamin D intakes

Canadian Aboriginal women have high rates of bone fractures, which is possibly due to low dietary intake of minerals or vitamin D. This study was undertaken to estimate dietary intake of calcium and vitamin D by designing a culturally appropriate dietary survey instrument and to determine whether disparities exist between Aboriginal and white women. After validation of a FFQ, 183 urban-dwelling and 26 rural-dwelling Aboriginal women and 146 urban white women completed the validated FFQ and had serum 25-hydroxyvitamin D [25(OH)D] measured. Urban Aboriginal women had lower (P=0.0004) intakes of total dietary calcium than urban white women; there was no difference in rural Aboriginal women. Only a minority of all women met the adequate intake (AI) for calcium intake. Ethnicity did not affect total vitamin D intake; however, rural Aboriginal women consumed all of their dietary vitamin D from food sources, which was more (P<0.03) than both urban Aboriginal and white women. Rural and urban Aboriginal women had lower (P<0.0004) serum 25(OH)D than urban white women. We found that 32% of rural Aboriginal, 30.4% of urban Aboriginal, and 18.6% of urban white women were vitamin D deficient, with serum 25(OH)D concentrations<37.5 nmol/L. The high prevalence of vitamin D deficiency among Aboriginal women, combined with lower dietary intake of calcium, especially in older women, likely contributes to the higher incidence of fracture in this population.