低钙透析液对腹膜透析患者钙磷代谢的影响

目的横断面研究腹膜透析患者使用低钙透析液的安全性及其影响因素。方法选择西安交通大学医学院第一附属医院肾脏内科腹膜透析超过6个月的患者共39例，其中男24例，女15例，年龄56．49±19．31岁，其中使用常规（ca 1．75mmol／L）透析液8例，低钙（ca 1．25mmol／L）透析液31例，比较两组血清钙、磷、甲状旁腺激素、血压以及使用碳酸钙的情况。结果两组血钙无明显差异；常规透析液组血磷和钙磷乘积高于低钙组，两组iPTH无明显差异。低钙组服用碳酸钙剂量明显高于常规透析液组。低钙组服用碳酸钙与未服用碳酸钙血钙无明显差异，服用碳酸钙组血磷控制较为理想、钙磷乘积更接近正常，未服用碳酸钙组血PTH明显升高。结论腹膜透析患者使用低钙透析液有利于控制血磷和血压，有效预防钙磷乘积升高。提高对碳酸钙的依从性是预防使用低钙透析液后引起继发性甲状旁腺功能亢进的关键。     

长期应用低钙透析对甲状旁腺激素的影响

目的：研究长期应用低钙透析液进行透析对患者甲状旁腺激素（parathyroidhormone,iPTH）的影响。方法：维持性血液透析患者16例,均使用钙浓度1.25 mmol/L的透析液透析3个月,比较血iPTH变化及透析前后的血钙磷水平的变化。结果：使用钙1.25 mmol/L的透析液3个月后,iPTH水平明显上升,透前血钙略有下降,透后血钙明显下降,血磷无明显变化。对于单次透析透后血iPTH较透前明显升高,下次透析前iPTH基本恢复,但略有上升。结论：长期应用（3个月）钙离子浓度1.25 mmol/L的透析液进行透析,会导致血iPTH的升高,但在可控制范围内。长期使用低钙透析时,应定期检查血的iPTH水平,以防发生继发性甲状旁腺机能亢进。     

调整腹透液钙浓度对尿毒症患者颈动脉粥样硬化的影响

目的观察调整腹透液钙浓度对持续性不卧床腹膜透析（㈣）患者颈动脉粥样硬化的影响。方法在规律性腹膜透析随访的患者中选择30例伴有颈动脉粥样硬化的患者，先予患者继续使用标准钙腹透液6个月后改用低钙腹透液（Baxter PD4：Ca^2＋1．25mmol／L，其余成分不变），同时增加碳酸钙用量，继续观察12个月，回顾分析患者的血清钙、磷、钙磷乘积及甲状旁腺素（iPTH）水平，颈动脉内-中膜厚度（IMT）、颈动脉血流阻力指数（R1）、颈动脉粥样斑块数量和超声分型的变化。同时观察使用低钙腹透液的不适症状。结果在继续使用标准钙腹透液的6个月中，患者血钙水平逐渐增加，颈动脉IMT增厚，RI增加，差异均有统计学意义。换用低钙腹透液治疗3个月后，颈动脉IMT变薄，RI较前明显下降（P〈0．05），血钙、磷及钙磷乘积明显下降（P〈0．01），iPTH明显增加（P〈0．01）。患者碳酸钙的每日口服剂量也由（2．27±0．41）g增加至（3．35±0．22）g（P（0．05）。在随后的9个月中，血钙、钙磷乘积均稳定在正常范围，血磷降至正常，iPTH 150ng／L左右；颈动脉IMT变薄（P〈0．01）、RI下降（P〈0．01），颈动脉粥样硬化斑块的超声分型及数量变化有统计学意义。治疗过程中，1例死亡，2例自行退出，其余患者均未有明显低钙抽搐、低血压等发生。结论低钙透析能显著减轻腹膜透析患者钙磷代谢紊乱对血管的毒性作用，有助于尿毒症患者颈动脉粥样硬化的转归。     

低钙透析液对血液透析伴继发性甲状旁腺功能减退患者的临床研究

目的：探讨应用含钙1.25mmol／L浓度透析液进行血液透析对维持性血液透析（MHD）伴相继发性甲状旁腺功能减退患者的钙磷代谢和甲状旁腺功能的影响。方法：选择MHD6个月以上、病情稳定、连续2次血iPTH〈100pg／ml的患者60例,随机分为对照组（含钙1.5mmol／L透析液）和治疗组（含钙1.25mmol／L透析液）,每组各30例,观察时间6个月。观察并记录研究前、研究后l、3、6个月等不同时期患者血iPTH、血清校正钙、磷、钙磷乘积等指标的变化以及相关不良反应。另外,选择使用含钙浓度1.5mmol／L和1.25mmol／L透析液进行MHD的患者各20例,检测单次透析前、透析结束时以及下次透析前的血清校正钙、磷和iPTH浓度。结果：（1）治疗组单次透析后血清校正钙、磷和钙磷乘积均较透析前明显下降,iPTH浓度较透前明显升高,P〈0.01;而对照组上述血钙和iPTH浓度无明显变化;（2）透析后治疗组血清校正钙和钙磷乘积较对照组明显下降,血iPTH浓度较对照组明显升高,P〈0.01;两组血磷浓度差异无统计学意义。（3）治疗组1个月后血清校正钙、磷和钙磷乘积较治疗前开始下降,3个月后进一步下降,P〈0.05,6个月后各项指标趋于稳定;iPTH水平1个月后较治疗前明显升高,并随着治疗时间的延长,逐渐升高,P〈0.01。（4）对照组治疗后1、3、6个月上述指标与治疗前比较差异无统计学意义。（5）两组透析过程中出现的不良反应差异无统计学意义。结论：对于血iPTH〈100pg／ml MHD患者应用含钙1.25mmol／L透析液进行血液透析能较好地控制其血清校正钙、磷、钙磷乘积水平,有效地改善被过度抑制的甲状旁腺功能,并且安全性良好。     

邯郸地区应用生理钙透析液对持续性腹膜透析患者钙磷代谢的影响

目的观察邯郸地区持续性腹膜透析患者随腹膜透析时间延长,应用生理钙透析液(Dianeal PD4)对其血钙、血磷及全段甲状旁腺素(intact parathyroid hormone,iPTH)水平的影响。方法回顾性分析2006年2月至2014年3月在我院住院首次诊断为终末期肾脏疾病(end-stage renal disease,ESRD)并行持续性不卧床腹膜透析(continuous ambulatory peritoneal dialysis,CAPE))治疗大于12个月的77例资料完整患者的临床资料,在应用生理钙透析液(钙浓度为1.25 mmol/L)进行维持性腹膜透析,并配合口服碳酸钙及骨化三醇条件下,观察透析后3、6、12个月血钙、血磷、iPTH、碱性磷酸酶(alkaline phosphatase,ALP)和血白蛋白、总白蛋白、尿素氮、肌酐、尿酸等各项生化指标水平,分析透析前后校正血钙、血磷、iPTH、ALP等指标变化情况,同时观察患者使用生理钙透析液有无低血压、抽搐、不宁腿、瘙痒等不适。结果患者血钙、磷、尿素、肌酐、尿酸、白蛋白、血红蛋白在生理钙透析液透析后3、6、12个月与透析初始比较,差异均有统计学意义(P0.05),而透析后3、6、12个月之间比较,差异均无统计学意义(P0.05)。患者iPTH在腹透开始后逐渐上升,但在透析后3、6个月与透析前比较,差异无统计学意义(P0.05),而透析12个月后与透析前比较差异有统计学意义(P0.05)。患者ALP和总白蛋白水平在透析前后无明显变化。结论邯郸地区应用生理钙透析液进行维持性腹膜透析的患者,在配合口服钙剂及活性维生素D制剂情况下,可有效改善患者钙磷代谢紊乱,从而防治继发性甲状旁腺功能亢进症及肾性骨病的发生。     

不同钙离子浓度透析液对血液透析患者钙平衡及甲状旁腺素的影响

目的研究不同钙离子浓度透析液对维持性血液透析(MHD)患者透析过程中钙平衡及全段甲状旁腺激素(iPTH)的影响,为透析患者个体化选择透析液钙离子浓度提供理论依据.方法 12例血钙正常的稳定的MHD患者分别使用钙离子浓度为1.25 mmol/L(DCa1.25)、1.5mmol/L(DCa1.5)和1.75 mmol/L(DCa1.75)的透析液进行血液透析(透析液其他成分不变),每次透析4 h.检测透析前后血清总钙(tCa)、离子钙(iCa)、iPTH及透析废液的iCa和磷(P),并对血压进行监测.结果使用DCa1.25时,患者体内丢失的钙平均为5.03mmol,但透后血iCa和tCa浓度与透前相比无明显变化,iPTH透后较透前显著升高(P＜0.05).使用DCa1.5时,患者体内钙的蓄积平均为1.4 mmol,透后血iCa和tCa浓度与透前相比明显升高(P＜0.01),其中25%的患者发生透后高血钙,iPTH较透前无明显变化;使用DCa1.75时,患者体内钙的蓄积平均为3.3 mmol,透后血iCa和tCa浓度比透前明显升高(P＜0.01),其中83.3%的患者发生透后高血钙,iPTH较透前明显降低(P＜0.01).3种透析液对血磷的清除无明显差异(P＞0.05).结论对于透前血钙水平正常的患者,DCa1.75的透析液明显增加了患者的钙负荷,增加了透后高钙血症的发生.DCa1.25的透析液能够明显减轻钙负荷,但长期使用应注意监测iPTH水平.对于透前轻度低血钙或在正常值低限的患者,DCa1.5的透析液是适用的,如果发生透后高钙血症,则应改用DCa1.25的透析液.     

复方α酮酸对维持性血液透析患者钙磷代谢的影响

目的评估复方α酮酸配合低蛋白质饮食对维持性血液透析患者钙磷代谢及营养状况的影响。方法选择我院维持性血液透析患者40例,随机分为2组,每组20例,观察组给予复方α酮酸加低蛋白质饮食;对照组给予碳酸钙,不限蛋白质饮食,共观察6个月。比较2组血磷、血钙、全段甲状旁腺素（iPTH）及患者体质量指数（BMI）、血红蛋白（Hb）、血浆白蛋白（Alb）、上臂肌围（MAMC）。结果与治疗前相比,治疗后,对照组血磷、血钙、钙磷乘积、iPTH呈升高趋势（P〈0．05或P〈0．01）,观察组血磷呈降低趋势（P〈0．01）,血钙、钙磷乘积呈升高趋势（P〈0．05）,iPTH无变化（P〉0．05）。与治疗前相比,治疗后,2组BMI、Hb、Alb、MAMC均呈升高趋势（P〈0．05）,组间无差异（P〉0．05）。结论复方α酮酸配合低蛋白质饮食可在不导致患者营养不良的同时有效纠正患者钙磷代谢紊乱。     

低钙透析联合高通量透析对钙磷代谢及营养状态的影响

目的观察低钙透析液联合高通量透析（HFHD）对尿毒症伴矿物质及骨代谢异常患者钙磷代谢及营养状态的影响。方法选择2009年1月至2009年12月我院维持性血液透析（MHD）患者23例,所有患者血钙处于正常高值或高钙血症或高钙磷乘积且血清全段甲状旁腺素（iPTH）水平升高,观察前所有患者使用钙离子浓度为1．5mmol／L的透析液和FreseniusF6透析器。将23例患者随机分为2组。A组12例,换用FreseniusF60高通量透析器;B组11例,继续使用FreseniusF6透析器。所有患者均换用钙离子浓度为1．25mmol／L的透析液,共观察12周。比较2组血钙、血磷、钙磷乘积、iPTH、血红蛋白（Hb）、血浆白蛋白（Alb）、前白蛋白（PAB）、超敏C反应蛋白（hs-CRP）、白细胞介素6（IL-6）、肿瘤坏死因子α（TNF-α）、肱三头肌皮皱厚度（TSF）和上臂中段肌肉周径（MAMC）。结果与观察前相比,A组观察后血钙、血磷、钙磷乘积、iPTH降低（P〈0．01）,Hb、Alb、PAB升高（P〈0．05）,hsCRP、IL-6、TNF-α降低（P〈0．01）,TSF升高（P〈0．01）,MAMC有升高趋势,但差异尚无统计学意义（P〉0．05）;B组血钙降低（P〈0．01）,其余各项指标无差异（P〉0．05）。观察后,A组血钙、钙磷乘积、iPTH低于B组（P〈0．01）,血磷及IL-6亦低于B组（P〈0．05）。无一例患者出现低血压及肌肉痉挛。结论低钙透析液联合HFHD可改善尿毒症伴矿物质及骨代谢异常患者钙磷代谢及营养状态。     

不同钙浓度透析液治疗甲状旁腺切除术后低钙血症的探讨

目的观察血液透析患者行甲状旁腺切除术后,使用不同钙浓度透析液纠正术后低钙血症的效果。方法回顾性分析2011年10月至2014年5月我院血液透析中心行甲状旁腺切除术的13例患者,根据术后透析治疗时使用的不同钙浓度透析液,分为A组(使用钙浓度1.50 mmol/L透析液)5例,B组(使用钙浓度1.75 mmol/L透析液)8例。分别观察2组患者术后当日、术后第3、6个月透析前后的血压及透析间期的血钙、血磷、全段甲状旁腺素(intact parathyroid hormone,iPTH),比较数值之间的变化;同时统计2组患者口服钙剂的用量,并通过彩色多普勒超声心脏瓣膜评估及胸部多层螺旋电子计算机断层扫描成像(multi-slice computed tomography,MSCT)所示心脏大血管的影像学表现,比较术前及术后第6个月患者冠状动脉钙化评分分值的变化。结果比较2组单次血液透析治疗时透析前与透析结束后4 h的血钙,2组透析结束后4 h的血钙较透析前均升高,差异有统计学意义(P0.05)。同时分别比较2组透析前与术后第3、6个月时血钙变化,差异有统计学意义(P0.05)。而2组之间透析前的血磷、iPTH无统计学差异(P0.05)。通过6个月调整治疗后,血钙较术后当日明显升高(P0.05),血磷明显下降(P0.05)。术后第6个月时,B组较A组口服钙片的剂量明显减少,血压明显上升(P0.05)。同时术前及术后第6个月心脏瓣膜评估及冠状动脉钙化评分分值无明显变化(P0.05)。结论高钙透析液能更好、更快的纠正术后出现的严重低钙血症,减少维持性钙片的服用剂量,但须注意异位钙化的风险及高血压的发生。     

低钙透析液对血液透析患者生活质量的影响

目的探讨低钙透析液（LCD）对维持性血液透析（MHD）患者生活质量（OOL）的影响。方法将30例血清矫正钙≥2．37mmol／L的MHD患者依据血甲状旁腺激素（iPTH）水平分为3组,均使用LCD透析3个月,比较3组患者使用LCD透析前后SF-36问卷评分值及血清钙、磷、钙磷乘积、iFrrH、骨钙素（BGP）水平。结果①透析后与透析前相比,Ⅰ组患者SF-36总分、生理健康总分（PCS）、生理功能、躯体职能（RP）、躯体疼痛（BP）及情感状况评分增高（P〈0．05）,总体健康、生命活力、社会功能及精神健康无差异;Ⅱ组患者PCS、RP和BP评分降低（P〈0．05）,余指标无差异;Ⅲ组各指标评分均无差异（P〉0．05）。②与透析前相比,Ⅰ、Ⅱ组患者透析后血清钙和钙磷乘积均降低（P〈0．05）,iPTH和BGP水平均升高（P〈0．05）;Ⅲ组无变化。结论LCD短期应用能显著提高无动力型骨病患者生活质量,尤其减轻躯体疼痛,长期使用可能影响患者生理健康从而对QOL产生负影响,LCD对MHD患者心理健康无明显改善。     

绝经后骨质疏松患者的缺钙和补钙的作用

２４例绝经后骨质疏松症患者分两组进行了钙平衡试验，年龄５６．３１±２．９９和５８．６６±４．２６，绝经年限１２．５±７．１１和１０．７７±４．５６，该组妇女平均食物钙摄入４２２．６ｍｇ／日，未补钙者平均负钙平衡１２．８８ｍｇ／日，补钙５００ｍｇ／日者平均正钙平衡３１８．２２ｍｇ／日，摄入钙的利用率占３３％，经２年单纯补钙，ＱＣＴ腰椎骨密度增高１３％，低钙摄入的妇女单纯补钙有一定预防骨质疏松的作用。     

Calcium supplements: Practical considerations

The preferable source of calcium is a balanced diet, but medicinal supplements are sometimes necessary if patients are to reach desired intakes. A divided dose regimen (4×/d; i.e., with meals and at bedtime) results in substantially greater absorption of a supplement than does l×/d dosing. However, differences in chemical solubility between supplement preparations are of little importance, with calcium carbonate preparations, for example, being absorbed as well or better than some much more highly soluble salts. Gastric acid is not necessary for absorption of even poorly soluble preparations, so long as they are taken with meals. Because typical patients exhibit a wide range of absorption efficiencies, it is desirable to assess absorption fraction before beginning a supplement regimen. (Some patients will need three times as large a dose as others to absorb the same amount of calcium.) Calcium intakes up to at least 62.5 mmol (2500 mg) are safe for virtually all patients.     

Comparison of calcium kinetics in man and the rat

The disappearance from the blood of intravenously-injected radiocalcium in man and the rat can be formally described by a two-termed exponential equation, which may be thought to have been generated by a two-compartment system in dynamic equilibrium with the environment. This paper reports an evaluation and comparison of the rate constants of such a system.In people over the age of 16, the mean system constant was 0.239 day^–1 (SE: 0.009) and the mean skeletal constant was 0.148 (SE: 0.008). The corresponding constants were 0.496 day^–1 (SE: 0.023) and 0.428 (SE: 0.019) for 4-month-old female Sprague Dawley rats and 0.744 (SE: 0.038) and 0.351 (SE: 0.021) for 10-month-old rats. All of the constants of the rats were significantly higher than those of man. There were no significant changes in man after the age of 16 years, whereas in the rat these constants changed with age.Differences in the constants can be explained by known differences in calcium metabolism and in the growth rates of the two species. Hence, a formal comparison of calcium kinetics in man and the rat yields information consistent with the interpretation that the two systems are comparable.Rate constants may prove useful for interspecies comparisons, as well as for studies of the regulation of calcium metabolism.These studies were supported in part by the National Institutes of Health (Grant No. AM 07983) and the National Dairy Council.     

In vitro dissolution of calcium carbonate preparations

Summary Calcium supplements are widely used for the treatment of osteoporosis. The bioavailability of these preparations is unknown. Because poor tablet dissolution accounts for a majority of drug bioavailability problems, we determined thein vitro dissolution at 30, 60, and 90 minutes of 27 commercially available calcium carbonate supplements using the method of the U.S. Pharmacopoiea. At 30 minutes, five preparations (18%) were more than 75% dissolved, four (15%) between 33 and 74%, and the remaining 18 (67%) were less than 33% dissolved. After 90 minutes, 17 (63%) of the preparations were less than 50% dissolved. Dissolution correlated negatively with the weight of filler (noncalcium carbonate material in the tablet) (r_s=−0.51,P<0.01) but not with tablet hardness or cost. Simila to previous studies, we also found no correlation of dissolution with the stated calcium content, chemical source of calcium carbonate (oyster shell or chemical precipitate), or retail source. We conclude that there is a wide range ofin vitro dissolution among the calcium carbonate preparations tested, and that the filler is an important determinant of the dissolution of these tablets. These results raise concern about the bioavailability of the calcium in these preparations and may have important implications for the therapeutic use of the various calcium carbonate supplements. This work was presented in part at the Tenth Annual Scientific Meeting of the American Society for Bone and Mineral Research, June 1988.     

Influence of accompanying anion on intestinal radiocalcium absorption

Summary To assess directly the effect of ionic dissociation on the bioavailability of calcium, we used the double isotope inverse convolution method to compare the absorption of calcium gluconate and calcium pyrrolidone carboxylate, an organic, highly dissociated salt. Two tests were performed at a 2 day interval, using in random sequence either salt as a carrier. Forty-eight subjects of various age and clinical condition were studied. The use of the more dissociated salt consistently and significantly increased fractional absorption in a rather constant ratio. Moreover, it slowed absorption in normal subjects whatever their age, and accelerated it in patients with chronic renal failure or osteoporosis, leading to inferences on the alteration of calcium absorption in these conditions.     

Classification of idiopathic hypercalciuric patients by isotopic calcium absorption: A comparison with oral calcium tolerance test

Summary To test the accuracy of calcium tolerance test in estimating calcium absorption, we have measured the radioactive calcium absorption (expressed as Fx) in 27 patients with IH and renal calcium stones. The results of this test were compared with those of a standard oral calcium tolerance test. Although only seven of nine AH patients displayed normal fasting calcium excretion, they all displayed Fx values above normal and a normal parathyroid activity. Conversely, only 5 of our 18 RH patients demonstrated a hyperabsorption of radioactive calcium and an elevation in iPTH and cAMP above normal limits, yet all of them showed an increased calciuric response to an oral calcium challenge. Calcium absorption was inversely related to iPTH (r=−082;P<0.001) and cAMP (r=−064P<0.05) in AH, but directly proportional to these parameters (r=0.62P<0.001 andr=0.46P<0.05, respectively) in RH patients. In view of these results, two ratios, iPTH/Fx and cAMP/Fx were used to discriminate between the two groups of patients. Both ratios were over normal limits in all RH patients and within normal range in all but one AH patient. Furthermore, no overlap was found between the two groups. Conversely, we were unable to completely separate AH from RH subjects on the basis of the oral calcium tolerance test, since in both groups the fasting and the absolute (or percentage) changes in urinary calcium, cAMP and blood iPTH levels following oral calcium loading, overlapped in each instance. The result of this study indicates that two indices, iPTH/Fx and cAMP/Fx, may prove particularly useful in differentiating AH from RH patients. Furthermore, since only a subgroup of patients with an abnormal calciuric response to an oral calcium load manifest an increase in calcium absorption, it is concluded that the calcium tolerance test overestimates calcium absorption in IH. Supported in part by Grant No. 5T32 AM0703310     

Comparison between the fractional isotopic calcium absorption and an oral calcium tolerance test

Summary In 27 subjects with several disorders of calcium metabolism, the fractional intestinal absorption of⁴⁷CaCl₂ was rather poorly correlated with the urinary output of calcium or with the maximal increase of serum calcium after an oral calcium load. Conversely, a good correlation was observed with the product of these parameters. We propose that this product be used as an estimate of intestinal calcium absorption when a radioisotopic method is not available.     

Oral calcium loading test and response to diuretics in normal taiwanese school children

To investigate possible mechanisms of increased urinary calcium excretion and increased prevalence of urolithiasis in 16- to 20-year-old children, oral calcium loading and diuretic tests were performed in 120 normal children in three age groups (7–8, 12–13, and 17–18 years of age). Urinary calcium/creatinine ratios and 24-h urinary calcium excretion were significantly increased following the oral calcium loading test in 17- to 18-year-olds compared with the two younger age groups. Oral furosemide resulted in increased urinary calcium excretion in the 17- to 18-year age group, while hydrochlorothiazide was less effective in reducing urinary calcium excretion in this age group. These results suggest that increased intestinal calcium absorption and decreased renal tubular reabsorption of calcium in 17- to 18-year-olds may be contributing factors in the increased prevalence of nephrolithiasis in older Taiwanese children.     

Caffeine and the calcium economy revisited

We report an analysis of data from 560 calcium balance studies carried out on 190 women aged 34.8–69.3 years at the time of study. The main purposes were to confirm a previously observed association between caffeine intake and calcium balance, and to attribute the association, if possible, to specific component(s) of balance. We found a caffeine relationship such that for every 6 fl oz (177.5 ml) serving of caffeine-containing coffee, calcium balance was more negative by 0.114 mmol/day (4.6 mg/day) (P<0.001). The relationship was localized to the input side of the balance equation, and both of its components (i.e. calcium intake and calcium absorption efficiency) were independently and inversely associated with caffeine intake. There was no evidence that the putative caffeine effect is confined to, or is greater among, subjects with low calcium intakes or those who are older or estrogen-deprived. The magnitude of the negative effect of caffeine on calcium balance suggests that it can be offset by increasing calcium intake by about 1 mmol (40 mg) for every 177.5 ml serving of caffeine-containing coffee.     

Comparison of the effect of gluconate, lactose, and xylitol on bone recalcification in calcium-deficient rats

The therapeutic value of three calcium absorption promoting carbohydrates, lactose, gluconate and xylitol, in bone calcification was evaluated in 7-week-old male rats which were fed on a semisynthetic Ca-deficient diet for 3 weeks. Lactose + CaCO₃, xylitol + CaCO₃, Ca-gluconate, or CaCO₃ alone were administered to the Ca-deficient rats for 2 weeks; the carbohydrate and Ca contents of the diets were 5% and 0.5%, respectively. The Ca-deficient rats showed a decrease in serum total Ca and ionized Ca²⁺ and in tibial Ca, Mg, P and density, with a concomitant increase in bone hydroxyproline concentration. Bone and serum tartrateresistant acid phosphatase activities were increased 2-fold and the serum 1,25(OH)₂D₃ level 5-fold. Smaller increases were found in serum calcitonin, PTH, alkaline phosphatase and osteocalcin levels. These changes (except calcitonin) were reversed by the administration of Ca and the carbohydrates. It was observed that all three agents improved the recalcification of bones compared with the effect of CaCO₃ alone. The effect of lactose and xylitol was superior to that of gluconate. These results suggest advantages in the use of xylitol in Ca-supplements.