藏族成年男子膳食中铁的吸收状况研究

目的：了解藏族成年男子膳食中铁的吸收利用，为修订膳食营养素参考摄入量(DRIs)和改善铁的营养状况提供理论依据。方法：选择15名藏族成年健康男子给予代表性试验膳进行14d代谢平衡实验，收集血液样品测定铁营养状况指标，采用火焰原子吸收光谱法测定受试者的膳食、饮水、粪便、尿液样品中铁的含量。结果：受试者的铁营养状况正常、稳定。铁摄入量为61．96mg／d，粪铁排出量为42．16mg／d，尿铁排出量为6．95mg／d；铁表观吸收率为32．02％；铁表观利用率为20．79％，高于现行的DRIs的制订依据。结论：代表性膳食中铁的摄入量可满足受试者的需要量。     

藏族成年男子膳食中锌的吸收状况研究

目的了解藏族成年男子膳食中锌的吸收利用,为修订膳食营养素参考摄入量(DRIs)和改善锌的营养状况提供理论依据。方法在营养调查的基础上设计出代表性的3d食谱,选择13名18~19岁的藏族健康男子给予试验膳进行14d的代谢平衡实验,收集试验期受试者的膳食、饮水、粪便、尿液样品,采用火焰原子吸收光谱法测定各样品中锌的含量,计算锌的表观吸收率、表观利用率。结果锌的表观吸收率为24·15%,与现行的DRIs的制订依据估计值接近;表观利用率为7·61%。结论代表性膳食中锌的摄入量能满足受试者的需要量。     

三例慢性放射病患者的氮平衡观察

选择三例慢性放射病患者进行了两期氮平衡实验,每期三日。第一期:当膳食中蛋白质摄入量为75.4～77.2g,热量为1586～1669kcal时,氮平衡为-0.01～-0.50g,第二期:当膳食中蛋白质和热量分别增加至97.2g和2467～2483kcal时,氮平衡为+2.37～+2.93g。两期的蛋白质、脂肪、糖的表观消化率基本相似,显然第一期出现的负氮平衡与蛋白质和热量摄取量不足有关。文中指出,在治疗慢性放射病患者时,应注意供给高热量和高蛋白质的膳食。     

代谢平衡法与粪便监测法评价藏族成年男子膳食锌吸收率的比较

目的:比较代谢平衡法(MB)和粪便监测法(FM)评价藏族成年男子膳食锌(Zn)吸收率。方法:进行14d人体现场代谢试验,受试者于D5晚一次性口服浓集67Zn的稳定性同位素示踪剂4.0mg及稀土元素镱(Yb)1.0mg,口服卡红标记、并收集D4~12的粪便和尿液样品,同时收集膳食、饮水样品;用感耦等离子体质谱仪测定粪样67Zn/68Zn的比值,并用原子吸收分光光度计分析所收集样品中的锌含量,比较用两种方法测定该人群膳食Zn吸收率的结果。结果:MB和FM评价藏族成年男子膳食Zn吸收率分别为(23.8±3.9)%、(21.4±4.3)%,二者的差异(配对t检验)和相关性(Pearson)均有统计学意义;未吸收的Zn示踪剂和Yb经胃肠道排出情况几乎一致,主要在口服后5d内排出。结论:14d代谢试验评价膳食Zn吸收率时,MB略高于FM,后者的试验期可依据Yb的排出情况缩短至4~5d。两种方法评价的结果都表明藏族成年男子膳食Zn吸收尚可。     

某高级中学住宿生膳食与营养状况调查

[目的 ]　为创建我区学生膳食示范点 ,为今后发展中学学生膳食探索经验。 [方法 ]　用记帐法和称量法调查2 71名住宿学生的膳食情况 ,并结合人体测量指标评估其营养状况。 [结果 ]　平均每日男女生能量和各种营养素摄入量分别为 :能量 (32 5 0± 16 4)kcal,(2 5 80± 172 )kcal;蛋白质 (112 .1± 10 .3) g ,(97.0± 9.7)g ;脂肪 (137.6± 11.5 ) g ,(136 .0± 10 .9) g ;碳水化物 (390 .6± 17.9)g ,(2 37.8± 18.0 ) g。蛋白质 /脂肪 /碳水化物供能比为 13 .8∶38.1∶48.1;15 .0∶47.4∶36 .9。脂肪供能占总热量比例超过 30 %。碳水化物供能比低于 5 0 %。来自动物及豆类的蛋白质占总蛋白质的 5 0 %以上。早中晚三餐热能分配为 2 1∶38∶41和 2 7∶35∶38。常量及微量元素中铁、钠、钾、磷、碘、铜、硒、锰均达中国居民膳食营养素参考摄入量(DRIs)要求 ;钙、锌男女生摄入量分别为DRIs 的 5 8.90 %和 5 6 .6 0 %、79.47%和 78.71%。维生素E、C和尼克酸均达DRIs要求 ;VitA摄入量男女分别为DRIs 的 6 3 .9%和 73 .1%。VitB2 摄入量男女分别为DRIs 的 83 .33 %和 90 .83 %。 [结论 ]　膳食结构基本合理 ,但应减少脂肪摄入 ,增加主食和菜果的供给量。     

彝族成年男子膳食中铁、锌、钙的生物利用研究

目的:评价彝族成年男子膳食中铁、锌和钙的生物利用情况,为防治该人群矿物质缺乏病提供基础信息。方法:以代谢平衡法于现场对12名20~22岁彝族世居地的成年男子进行14d试验。试验开始,收集对象空腹血,检测血红蛋白、红细胞压积、血清铁蛋白、血浆锌和钙浓度。试验期间,收集4~12d试验膳及摄入试验膳后排出的粪便和尿样。应用火焰原子吸收法测定膳食、粪便和尿中三种矿物质的含量,分别计算出它们的表观吸收率、平衡状态和表观利用率。结果:彝族成年男子代表性膳食中铁、锌和钙的表观吸收率(%)分别为15.8±6.2、24.5±4.1、32.3±9.7;表观利用率(%)分别为1.9±5.7、12.8±4.3、5.5±15.9。平衡试验显示铁,锌,钙均为平衡,但钙的变动范围较大。结论:膳食中铁、锌摄入量能满足试验对象的需要量,而钙的摄入量则不能满足其需要量。三种矿物质的表观吸收率与表观利用率基本上与我国正常人相同。建议彝族居民增加钙含量高的食物摄入量,以预防钙缺乏。     

稳定性同位素评价藏族青年男子膳食铁的吸收率

目的用铁的稳定性同位素示踪剂评价藏族青年男子膳食铁的吸收率,为改善该人群膳食铁吸收的提供参考数据。方法于现场进行人体代谢试验,受试者口服稳定性同位素示踪铁剂(浓集57Fe的FeSO4)及稀土元素镝,粪便监测法收集示踪剂排出粪样;用感耦等离子体质谱仪测定粪样57Fe56Fe的比值,分析评价该人群膳食铁的吸收率。结果口服同位素评价藏族青年男子膳食铁的吸收率为13.4%±6.4%;每日示踪剂铁和镝排出呈良好相关性。结论稀土元素镝与未吸收的示踪剂铁在消化道有一致的排出过程,前者的回收率能很好反映粪样收集情况;藏族成年男子膳食铁的吸收较好。     

运用半定量食物频率调查法评估拉萨农村藏族婴幼儿母亲的膳食结构

目的 了解2岁以下藏族农村儿童的母亲膳食结构特点.方法 采用半定量食物频率问卷于2008年对拉萨农村2岁以下藏族儿童的母亲进行横断面调查.结果 共调查386名农村2岁以下藏族儿童母亲,平均年龄28.5岁,平均受教育年限为4.6年.其家庭人均消费植物油25.9 g/d,显著低于全国平均水平(P＜0.01),动物性油脂中酥油、糖和盐的人均每日消费量分别为27.8 g、12.9g和14.8 g,显著高于全国平均水平(P＜0.01).共调查91种食物.其中22种食物的中位摄入频率为每周一次及以上.因子分析提取三个主要因子,反映三种膳食结构类型,第一因子是植物性膳食结构,其特点是以蔬菜、谷类、水果为主,辅以少量肉类、奶和豆制品,是该人群的主导膳食;第二因子是藏族特色膳食,主要摄入以糌粑为代表的富有藏族特色的食物,辅以简单蔬菜;第三因子是以肉类和奶制品为主的膳食,富有藏族特色.妇女每日平均摄入能量2097.02 kcal,达到膳食营养素参考摄入量(RNI)的91.2%,蛋白质的摄入量只达到RNI的82%,维生素A摄入量只相当于RNI的34.7%,钙、铁和锌的摄入量相当于RNI的64.6%、174.1%和150.7%.65%的能量来自谷类,动物性食物只提供了7.4%的能量和15.5%的蛋白质,57.6%的铁来自糌粑.结论 拉萨农村2岁以下藏族儿童母亲的膳食以植物性食物为主,膳食结构单调,存在蛋白质、能量及微营养素摄入不足.     

长春市城乡居民膳食结构与营养状况调查

目的了解长春市居民膳食营养状况,为营养教育和营养改善工作提供科学依据。方法采用分层整群随机抽样方法,对644户居民970人进行家庭膳食调查,并与中国居民膳食营养素参考摄入量(DRIs)比较,分析营养素摄入达标状况。结果长春市居民每日人均能量摄入为2 212.78 kcal,占推荐摄入量(RNIs)的96.21%。蛋白质摄入量为46.42 g/d,占推荐摄入量(RNI)的77.37%,农村高于城区;脂肪摄入量为135.02 g/d,硫胺素和核黄素摄入量分别占RNIs的47.15%和63.57%;钙、磷、铁摄入量分别为161.90 mg/d、609.90 mg/d和8.49 mg/d,分别为RNIs的20.24%、87.13%和56.60%。城市蛋白质、碳水化合物来源以粮谷类为主,农村蛋白质、脂肪则以动物类为主。B1、B2硫胺素和Ca摄入量偏低。结论长春市居民主要营养素摄入量基本满足人体需要,加强居民合理营养、平衡膳食的宣传教育,预防营养相关疾病发病率上升,加强饮食指导是提高当前城乡居民营养水平的重要措施之一。     

山东省农村儿童代表性膳食中铁、钙吸收率分析

目的研究山东省农村学龄前儿童代表性膳食中铁、钙的吸收率,以及膳食因素对其吸收利用的影响.方法用代谢平衡法.使用原子吸收分光光度计（AAS）测定膳食与粪便的铁、钙含量,计算铁、钙的吸收率.同时测定影响铁、钙吸收的因子膳食脂肪、蛋白、植酸、纤维素和维生素C（VC）的含量,计算日平均摄入量,将其结果与我国儿童每日推荐膳食营养素摄入量（RNI）进行比较.结果铁、钙的吸收率分别为6.10%,53.09%,铁的平均日摄入量为11.80mg,占RNI的98.3%,低于推荐量;钙的平均日摄入量为295.40mg,占RNI的36.92%,低于推荐量.蛋白质和VC的日摄入量分别为31.2g与13.3mg,占RNI的56.73%和29.60%,低于推荐量.脂肪、植酸和膳食纤维的摄入量较高.结论在蛋白质和抗坏血酸的日摄入量较低,脂肪、植酸和膳食纤维的摄入量较高的条件下,铁吸收率较低,铁营养缺乏.钙摄入量显著低于RNI,显示钙摄入严重不足.     

Human protein requirements: the effect of variations in energy intake within the maintenance range.

Protein requirement studies in man generally avoid deficient dietary energy intakes because they decrease the efficiency of nitrogen utilization, but the opposite effect of excess dietary energy is usually overlooked. Four young men were fed the 1973 FAO/WHO safe level of egg protein (0.57 g/kg) at several levels of dietary energy. The data indicate that a significant proportion of the population may require excess energy intakes to maintain nitrogen balance at this level of dietary protein. Variations in dietary energy ranging from submaintenance to 15 to 20% above estimated maintenance needs altered net egg protein utilization in three subjects by 2 to 4.5 units/kcal per kg body wt.     

Effect of reduced energy intake versus increased physical activity on the outcome of nitrogen balance experiments in man

The effects of energy deficiency created by a reduced energy intake versus an increased physical activity on urinary nitrogen excretion, nitrogen balance and the biological value of the dietary protein (0.57 g/kg/day from a mixed diet) are reported. Two experiments, 21 and 27 days respectively, designed to even out possible effects of time on nitrogen balance, were conducted on 12 young adult men and women. During energy deficiency, urinary nitrogen increased while nitrogen balance and biological value decreased. No significant differences between the two kinds of energy deficiency were found but the effect on the parameters studied tended to be less pronounced the longer the subjects had been on the experimental diets.     

四川省少数民族地区肠道蠕虫感染现状调查

目的了解四川省藏族农区和彝族地区肠道蠕虫感染现状。方法对省内甘孜州3个藏族县和凉山州1个彝族县3岁以上的部分人群用粪便生理盐水直接涂片显微镜查蠕虫卵。结果共检查了2 653人,其中424人感染肠道蠕虫,感染率为15.98%。查出的肠道蠕虫有蛔虫、鞭虫和蛲虫等土源性线虫以及带绦虫,土源性线虫感染率为10.74%,带绦虫感染率为5.24%。藏区和彝区均有带绦虫分布,感染率分别为5.52%和1.57%。土源性线虫彝区感染率为80.63%,藏区5.32%。青壮年带绦虫病感染率明显高于其他年龄段人群,而青少年和儿童土源性线虫感染率最高。结论四川省藏族农区和彝族地区带绦虫病高度流行,土源性线虫在彝族地区的流行尤为严重。相关部门应给予高度重视,综合性防控措施急需实施以减轻疾病危害、维护社会稳定。     

Protein utilization by young women consuming animal or plant protein diets at various levels of vitamin B-6 intake

Eight young women consumed a vitamin B-6 depletion diet (egg albumen formula, less than 0.05 mg vitamin B-6/d) for 11-28 d. Subjects (n = 4) then consumed either animal protein (AP, mainly dairy and poultry products) or plant protein (PP, mainly various types of beans) diets with increasing vitamin B-6 intake (0.5, 1.0, 1.5, and 2.0 mg/d) for periods of 14-21 d. All diets provided 1.55 g protein/kg body wt. Apparent protein digestibility of AP (94.6%) was significantly higher than that of PP (88.4%) diets (p less than 0.001). Protein digestibility was not significantly affected by vitamin B-6 intake. Apparent nitrogen balance of subjects consuming AP diets was slightly, though not significantly, higher than that of subjects fed PP diets. N balance was not influenced by vitamin B-6 intake. Data suggest that short-term low vitamin B-6 intake does not affect protein utilization in humans as determined by digestibility and N balance.     

Human protein requirements: interrelationships between energy intake and nitrogen balance in young men consuming the 1973 FAO/WHO safe level of egg protein, with added non-essential amino acids

Our recent studies have shown that the 1973 FAO/WHO "safe level of intake" of egg protein (0.57 g/kg/day) is inadequate for maintaining protein nutritional status in young men receiving generous energy intakes. Therefore, an experiment was conducted to determine nitrogen (N) balance and the energy intake needed to support it when supplementary N, equivalent to 0.23 g of protein (N X 6.25)/kg/day from a nonessential amino acid mixture, was added to a diet containing 0.57 g of egg protein/kg/day. Four young men, 20 to 21 years old, participated in the 58- to 79-day metabolic N balance study. This group required significantly lower energy intakes to maintain N balance than a previously studied group fed only 0.57 g of egg protein under identical conditions. The energy intakes predicted to maintain N balance were approximately 10 to 15% less than the requirements estimate from body weight and N balance data. Present results, although based on a limited number of subjects, suggest that total N may be the limiting factor in short-term N balance at the 1973 FAO/WHO egg protein intake level for a significant proportion of young adult male populations. Long-term metabolic studies will be necessary before the practical significance of the observations can be determined.     

Short-term low-protein intake does not increase serum parathyroid hormone concentration in humans

We investigated whether inadequate dietary protein would result in increased serum parathyroid hormone (PTH) concentration, consistent with secondary hyperparathyroidism. Data from 2 controlled feeding studies were utilized. In study 1, 26 healthy women (15 young, 21-46 y, and 11 elderly, 70-81 y) consumed for 12 d each in separate trials 3 levels of protein, 1.00, 0.75, and 0.50 g protein/(kg. d). Blood was drawn from fasting subjects on d 12 of each trial. In study 2, 24 persons (54-80 y) were fed diets with either 1.20 g protein/(kg. d) for 2 wk (HPro, n = 11, 6 men, 5 women) or 1.2 g protein/(kg. d) for 1 wk and then 0.50 g protein/(kg. d) for a 2nd week (IPro, n = 13, 6 men, 7 women). Blood was obtained from fasting subjects after wk 1 and 2. Consistent with altered protein metabolism, urinary total nitrogen excretion and blood urea nitrogen fell progressively with decreasing protein intake in study 1; in study 2, the values decreased from wk 1 to 2 in the IPro group only. Serum intact PTH concentrations did not differ among the 3 protein intakes in study 1, or between the HPro and IPro groups in study 2. These findings do not support the hypothesis that the short-term ingestion of inadequate dietary protein increases serum PTH concentration.     

Increasing habitual protein intake results in reduced postprandial efficiency of peripheral, anabolic wheat protein nitrogen use in humans

BACKGROUND: The postprandial retention of dietary protein decreases when the prevailing protein intake increases. OBJECTIVE: We investigated the influence of the prevailing protein intake on the regional utilization and anabolic use of wheat protein during the postprandial non-steady state in humans. DESIGN: Healthy adults (n = 8) were adapted for 7 d, first to a normal-protein diet (NP: 1 g x kg(-1) x d(-1)) and then to a high-protein diet (HP: 2 g x kg(-1) x d(-1)). After each adaptation period, the subjects received the same single, solid mixed meal containing [15N]-labeled wheat protein. The postprandial kinetics of dietary nitrogen were then measured for 8 h in blood and urine. These data were further analyzed by using a multicompartmental model to predict the postprandial kinetics of dietary nitrogen in unsampled pools. RESULTS: The postprandial whole-body retention of wheat protein nitrogen, measured 8 h after meal ingestion, decreased by 10% when the subjects switched from the NP diet to the HP diet. According to modeling results, this resulted from an increased splanchnic utilization of dietary nitrogen for urea production, whereas its incorporation into splanchnic proteins was unchanged, leading to a 20-30% decrease in peripheral availability and anabolic use in HP-adapted compared with NP-adapted subjects having ingested the same protein load. CONCLUSIONS: By combining clinical experimentation with compartmental modeling, we provide a global overview of postprandial dietary protein metabolism. Increasing prior protein intake was shown to reduce the postprandial retention of wheat protein nitrogen, mainly by diminishing the efficiency of its peripheral availability and anabolic use.     

Nitrogen balance of healthy Dutch women before and during pregnancy

BACKGROUND: Experimental studies including longitudinal nitrogen balance studies could provide insight into protein metabolism in pregnancy. OBJECTIVE: Our aim was to determine the development of nitrogen balance during pregnancy compared with nitrogen balance before pregnancy in women consuming imposed constant diets. We also tracked changes in muscle mass and lean body mass by measuring urinary 3-methylhistidine (3-MeH) and urinary creatinine. DESIGN: Nitrogen balance was determined over 8 d in 12 healthy Dutch women before pregnancy and at weeks 12, 23, and 34 of gestation. Complete daily diets were supplied during each balance period so that each subject's energy, protein, and macronutrient intakes were similar in amount and composition in all 4 balance periods. RESULTS: Throughout pregnancy there was no significant change in loss of nitrogen in feces and therefore no change in protein digestibility. The amount of nitrogen excreted in urine in late pregnancy (11.0 +/- 1.4 g/d) was significantly (P < 0.01) less than in early pregnancy (12.6 +/- 1.3 g/d). Nitrogen retention increased toward term, even though energy balance became progressively negative. The difference between the first (-0.4 +/- 1.7 g N/d) and third (1.2 +/- 1.6 g N/d) trimester was significant (P < 0.05). No differences were found in either 3-MeH or creatinine excretion between trimesters. CONCLUSIONS: These urinary nitrogen excretion and nitrogen retention data show that when the dietary supply remains constant, nitrogen balance increases toward the end of pregnancy, suggesting a more efficient use of dietary protein later in pregnancy. Urinary 3-MeH and creatinine excretion indicated no change in protein metabolism.     

1989-2006年中国九省(区)居民膳食纤维摄入状况及其变化趋势

目的 分析1989-2006年中国9个省(自治区)18～45岁健康居民膳食纤维的摄入状况、膳食纤维食物来源及其的变化趋势.方法 以1989、1991、1993、1997、2000、2004和2006年中国健康与营养调查项目中连续3 d 24 h回顾法膳食调查数据为基础.将有完整膳食调查资料的18～45岁健康居民作为研究对象,7轮调查的样本量分别为5597、5596、5323、5485、5308、4144和3889名.比较不同时间、性别、地区居民膳食纤维摄入量及其食物来源地变化趋势.结果 9个省(自治区)18～45岁健康居民平均每天不溶性膳食纤维摄入量由1989年的15.1 g/d下降到2000年的11.6 g/d,总膳食纤维摄入量由22.6g/d下降到17.8 g/d.2000年农村男女平均每天不溶性膳食纤维的摄入量分别比1989年减少5.1和5.2 g(2000年分别为13.2、11.8 g;1989年分别为18.3、17.0 g),2006年农村男性和女性平均每天不溶性膳食纤维的摄入量分别为13.5和12.0 g/d.1989-2006年间城市男性和女性平均每日不溶性膳食纤维摄入量分别波动在9.4～11.8 g/d和8.3～10.8g/d,总膳食纤维的摄入量男性和女性分别波动在15.7～17.6和13.5～16.4g/d.城乡居民不溶性膳食纤维和总膳食纤维摄入量的差距呈现缩小的趋势.2006年70.6%(8.4/11.9)的不溶性膳食纤维来自蔬菜[(4.1±3.1)g/d]、面及其制品[(2.6±3.6)g/d]和米及其制品[(1.7±1.3)g/d].结论 1989-2006年9个省(自治区)居民膳食纤维摄入量呈现下降趋势.蔬菜、米、面及其制品是膳食纤维的主要食物来源.

Abstract：

Objective To analyze the status and trend of dietary fiber intake and its food sources among Chinese residents aged 18-45 years old in 9 provinces(autonomous region),from 1989 to 2006.Methods Twenty-four-hour dietary recall data of three consecutive days from China Health and Nutrition Survey(1989,1991,1993,1997,2000,2004 and 2006)were used.And the 18-45 years old subjects with complete information on dietary survey were included.The sample size of these 7 surveys were 5597,5596,5323,5485,5308,4144 and 3889,respectively.The trends of dietary fiber intake and food sources by time and sex were studied.Results From 1989 to 2000,the total of daily dietary fiber intake of 18-45 years old healthy residents decreased from 15.1 g/d to 11.6 g/d,insoluble dietary fiber intake decreased from 22.6 g/d to 17.8 g/d.In villages,from 1989 to 2000,the insoluble dietary fiber intake decreased 5.1 g/d in males and 5.2 g/d in females(13.2,11.8 g in 2000,respectively; 18.3,17.0 g in 1989,respectively).In 2006,the insoluble dietary intake was 12.6 g/d in males and 11.2 g/d in females in villages.In cities,from 1989 to 2006,the insoluble dietary fiber intake was 9.4-11.8 g/d in males and 8.3-10.8 g/d in females.The total dietary fiber intake was 15.7-17.6 g/d in males and 13.5-16.4 g/d in females.The difference of insoluble and total dietary fiber intake between city and village was decreasing.In 2006,70.6%(8.4/11.9)insoluble dietary fiber came from vegetables((4.1 ± 3.1)g/d),wheat flour and its products((2.6 ± 3.6)g/d),rice and its products((1.7 ± 1.3)g/d).Conclusion Dietary fiber intake among Chinese aged 18-45 in 9 provinces(autonomous region)decreased from 1989 to 2006.Vegetables,wheat flour,rice and their products were the major food sources of insoluble dietary fiber.     

Contribution of dietary protein and inorganic sulfur to urinary sulfate: toward a biomarker of inorganic sulfur intake

BACKGROUND: Sulfiting agents are widely used as food additives. Limits are set on their use in foods because they may adversely affect health. Sulfiting agents are excreted in urine as sulfate, which is indistinguishable from sulfate derived from sulfur amino acids. OBJECTIVE: The objective was to assess the contribution of inorganic sulfur to urinary sulfate excretion and of dietary protein to urinary sulfate and nitrogen excretion with the aim of developing a urinary biomarker of inorganic sulfur intake. DESIGN: Nine healthy men were fed a sequence of 3 diets for 15 d (n = 7), 5 diets for 10 d (n = 6), or both. The diets contained 51-212 g protein/d (0.43-1.71 g S/d) and 0.17-0.27 g inorganic S/d; p-aminobenzoic acid-validated 24-h urine samples (n = 47) were analyzed for sulfate and nitrogen. RESULTS: Dietary inorganic sulfur was efficiently excreted as sulfate in urine. Urinary sulfate derived from protein correlated strongly (r(2) = 0.86) with urinary nitrogen. Urinary recovery of protein sulfur and nitrogen decreased from 84% at average protein intakes (72 g/d) to 70% at high protein intakes (212 g/d). The nitrogen:sulfur ratio (in g) of the protein in the study diets was 18.9, which was maintained in urine (18.4 +/- 0.1) after dietary inorganic sulfur intake was subtracted from urinary sulfate. Therefore, inorganic sulfur intake (g/d) = urinary sulfur (g/d) - 0.054 x urinary nitrogen (g/d). For typical UK intakes of inorganic sulfur (0.25 g/d), this biomarker should produce mean (+/- SD) values of 0.24 +/- 0.10 g S/d. CONCLUSION: Twenty-four-hour urinary nitrogen and sulfate values can be used to predict inorganic sulfur intake.