Dietary Exposure to Lead and Cadmium in Yugoslavia

Abstract

Lead exposure still represents a matter of health concern especially in Yugoslavia. To assess the exposure of normal urban population to lead and cadmium through food, a preliminary monitoring was performed on a small group of urban population. Lead, cadmium and some essential elements (calcium, zinc, iron, copper and manganese) were analysed in collected duplicate diet samples and compared to similar population in Sweden. We found that dietary exposure to lead and cadmium is similar to other countries although Yugoslav urban population is exposed to much higher concentrations of lead in air than in cities of developed countries, due to high lead in gasoline. However, daily intake of some essential elements was significantly lower.

Also populations living around lead smelters in various parts of Yugoslavia are still exposed to elevated environmental lead and cadmium levels. To assess the exposure of the population living in this area, a cumulative long-term exposure to lead was determined by measuring lead in deciduous teeth. Concentrations of lead and cadmium in vegetables, soil and meals from the same region were also analysed. Values obtained for lead and cadmium in food products grown in exposed and control area were found to be related to respective concentrations of these elements in soil as well as to the distance from the smelter. Meals prepared in this region show the same trend, revealing very high intake particularly of lead.

The influence of nutritional factors, i.e. dietary calcium on lead metabolism, was also studied. Blood lead concentration was determined in two groups of peasant women living in two regions with different dietary calcium intake. Lower blood lead values were found in the higher dietary calcium intake region.     

The calcium requirement and factors causing calcium loss

Studies carried out under strictly controlled conditions during different calcium intakes in adult males have shown that the average calcium balance was only slightly positive (+22 mg/day) during a calcium intake of 800 mg/day, the recommended dietary calcium intake, not taking into consideration dermal losses of calcium. During this calcium intake, the calcium balances were negative in 34% of the subjects studied. Increasing the calcium intake to 1200 mg/day resulted in a significant increase of the calcium balance; further increases to different intake levels up to 2300 mg/day did not improve the calcium balance further. Increasing the phosphorus intake up to 2000 mg/day as well as increasing the protein intake from 1 g/kg body weight to 2 g/kg, given as meat, did not have an adverse effect on calcium metabolism. A variety of drugs, notably aluminum-containing antacids, induced calcium loss. Increasing the calcium intake more than 10-fold from 200 to 2500 mg/day did not lower the blood pressure in a large number of normotensive patients and in a small number of hypertensive patients studied.     

The role of vitamin D receptor gene polymorphisms in the bone mineral density of Greek postmenopausal women with low calcium intake

The aim of this study was to investigate the effect of common vitamin D receptor (VDR) gene polymorphisms on the bone mineral density (BMD) of Greek postmenopausal women. Healthy postmenopausal women (n=578) were recruited for the study. The BMD of the lumbar spine and hip was measured using dual-energy X-ray absorptiometry with the Lunar DPX-MD device. Assessment of dietary calcium intake was performed with multiple 24-h recalls. Genotyping was performed for the BsmI, TaqI and Cdx-2 polymorphisms of the VDR gene. The selected polymorphisms were not associated with BMD, osteoporosis or osteoporotic fractures. Stratification by calcium intake revealed that in the low calcium intake group (<680 mg/day), all polymorphisms were associated with the BMD of the lumbar spine (P<.05). After adjustment for potential covariates, BsmI and TaqI polymorphisms were associated with the presence of osteoporosis (P<.05), while the presence of the minor A allele of Cdx-2 polymorphism was associated with a lower spine BMD (P=.025). In the higher calcium intake group (>680 mg/day), no significant differences were observed within the genotypes for all polymorphisms. The VDR gene is shown to affect BMD in women with low calcium intake, while its effect is masked in women with higher calcium intake. This result underlines the significance of adequate calcium intake in postmenopausal women, given that it exerts a positive effect on BMD even in the presence of negative genetic predisposition.     

Blood pressure in relation to dietary calcium intake, alcohol consumption, blood lead, and blood cadmium in female nonsmokers

The interrelationship of dietary calcium (Ca) intake, alcohol consumption, blood lead (BPb), blood cadmium (BCd), age, and body mass index (BMI) to blood pressure was examined in 267 peasant women 40-85 years of age. They were residents of two rural areas in Croatia and differed with regard to dietary Ca intake: 100 women with low Ca intake (approximately 450 mg/day) and 167 women with relatively high Ca intake (approximately 940 mg/day). All of the women were nonsmokers and consumed very little or no alcohol. Median and range BPb values were 74 (29-251) microg/L in women with low Ca intake and 59 (21-263) microg/L in women with high Ca intake (p < 0.0002), whereas corresponding BCd values were 0.6 (0.2-3.6) microg/L and 0.6 (0.3-4.5) microg/L (p > 0.10). Results of multiple regression showed a significant (p < 0.05) increase in systolic blood pressure with age, BMI, and BCd, and marginally with alcohol consumption (multiple r = 0.48, p < 10(- 6)). An increase in diastolic blood pressure was significantly (p < 0.05) associated with BMI, age, and residence area (i.e., it was higher in women with low Ca intake), and marginally with BCd, and alcohol consumption (multiple r = 0.38, p < 10(-6)) When the two groups of women with different Ca intake were subdivided into consumers and nonconsumers of alcohol, BPb was related positively to alcohol consumption and inversely to Ca intake. The highest BPb was found in the subgroup of alcohol consumers with low Ca intake, and the lowest BPb in the subgroup of nonconsumers with high Ca intake: 78 (42-251) microg/L and 51 (22-192) microg/L, respectively (p < 10(-8)). Diastolic blood pressure was significantly higher in the former subgroup as compared to the latter: 95 (72-130) mm Hg and 90 (60-120) mm Hg, respectively (p < 0.05). This cannot be explained by age, BMI, or BCd, which were comparable in the two subgroups. The results indicate that alcohol consumption and low Ca intake can increase BPb, which may significantly contribute to an increase in diastolic blood pressure in female nonsmokers even at relatively low-level Pb exposure.     

Calcium intake, food sources and seasonal variations in eastern Croatia

The objective of this study was to examine the quantity of calcium intake among adults, the sources of calcium, differences among seasons, as well as the differences between sexes, correlation with body mass index (BMI), and age. The study included 161 healthy volunteers from the eastern part of Croatia. Each subject completed three food frequency questionnaires (FFQ) with 150 items, at an interval of 3-4 months. The mean calcium intake for whole population for all three FFQs was 965 mg/day. At the same time, the quantity of calcium for all subjects was 14.2 mg/kg, women 14.5 mg/kg, and men 13.6 mg/kg, respectively. There was an inverse relation between calcium intake and age for men (r = -0.32 p = 0.028), but not for women. Correlation between calcium intake and BMI was negative, but not significantly. Milk and dairy products were the main source of calcium. Marginally low mean calcium intake goes to show the needful to educate the population.     

Regional adipose tissue metabolism in postmenopausal women after treatment with exogenous sex steroids

In order to evaluate the effect of exogenous sex steroids on adipose tissue metabolism, two groups of postmenopausal women were studied. In one of the groups, the effect of 50 micrograms ethinyl estradiol (EE) was investigated given orally alone and in combination with 10 mg norethisterone acetate (NET). This combination is reminiscent of an old high dose oral contraceptive. In the other group, the effect of 3 mg 17 beta-estradiol was evaluated when administered percutaneously alone and in combination with 300 mg micronized progesterone given orally. These substances and doses were chosen to provide a "physiological" hormonal influence. In the femoral region 50 micrograms EE induced an increase in LPL activity. This elevated LPL value was reversed with the addition of 10 mg NET. Moreover, during treatment with 50 micrograms EE, a decrease in norepinephrine stimulated lipolysis was seen in the abdominal region. The percutaneous administration of 17 beta-estradiol with or without micronized progesterone, however, was inert as regards subcutaneous adipose tissue metabolism. Our findings indicate, therefore, that EE in doses used in oral contraception might promote lipid accumulation in the femoral adipose tissue depot.     

Effects in rats of iron on lead deprivation

In two fully crossed, two-factor experiments, F1 generation male rats were fed a basal diet supplemented with lead (lead acetate) at 0 or 2 micrograms/g and iron (ferric sulfate) at 50 or 250 micrograms/g (Experiment 1). Supplements in Experiment 2 were lead at 0 or 1 micrograms/g and iron at 50, 250, or 1000 micrograms/g. After 28 or 50 d in Experiment 1, and 35 d in Experiment 2, a relationship between lead and iron was found. Body weight was lower in low-lead than lead-supplemented 28-d-old rats regardless of dietary iron, whereas hematocrit and hemoglobin were lower in low-lead than lead-supplemented rats fed 50 micrograms iron/g diet. A similar finding was obtained with hematocrit and hemoglobin in 35-d-old rats. Dietary lead did not affect rats fed 250 or 1000 micrograms iron/g diet. Also, feeding low dietary lead did not affect 50-d-old rats regardless of dietary iron. Liver and bone concentrations of lead were markedly affected by dietary lead and iron. The concentration of lead in liver and bone was lower in low-lead than lead-supplemented rats. Compared to rats fed 50 micrograms iron/g diet, rats fed 250 micrograms iron/g diet exhibited a decreased lead concentration in liver and bone. This decrease was accentuated by lead supplementation. The findings suggest that lead acted pharmacologically to affect iron metabolism in rats.     

Calcium in the diet of selected groups of people]

Calcium-content was determined in 23,557 daily food rations of the individuals fed individually or in sets of food or meals prepared in various institutions (3,298) in 1975-1987. Calcium deficit in daily food of girls and adult women has ranged from 50% to 6.2% in comparison with daily intakes recommended in Poland. Mean content of calcium per 1000 kcal ranged from 191.6 mg to 276.2 mg in 24 of the analysed meals. Calcium deficit amounted to 14-37.4% in 20 out of 24 analysed daily meals for boys and men. Calcium content in the remaining daily food rations was equal or even higher than the Polish daily intake recommendation. A mean calcium content per 1000 kcal ranged from 211.6 mg to 342.1 mg. These results suggest, that the daily calcium intake in several groups of the general population is to low, especially in women. Authors suggest, that such a low calcium intake in the diet increases the risk of osteoporosis, and intoxications with lead and cadmium salts, especially in children.     

二苯基脲磺酸钙对小麦苗抗旱性的影响

用浓度为100mgL^-1的二苯基脲磺酸钙溶液喷小麦苗期叶片,能明显增加小麦幼苗的过氧化物酶、过氧化氢酶和超氧化物岐化酶的活性,并使保水力和复活能力增强。用100mgL^-1DSC拌种,还可提高小麦种子在干旱条件下的萌发率。     

Soy isoflavones, CYP1A1, CYP1B1, and COMT polymorphisms, and breast cancer: a case-control study in southwestern China

CYP1A1, CYP1B1, and COMT are key enzymes involved in estrogen metabolism. Soy isoflavones, phytoestrogens found in soy foods, may modify the activity of these enzymes. A case-control study was conducted to assess the associations between soy isoflavone intake and the CYP1A1 Ile462Val, CYP1B1 Val432Leu, and COMT Val158Met polymorphisms and breast cancer, as well as their combined effects on breast cancer. A total of 400 newly diagnosed breast cancer cases and 400 healthy controls were recruited. Participants' daily intake of soy isoflavones (DISI [mg/day]) was calculated and transformed to energy-adjusted DISI by the residual method. Gene sequencing was used to analyze CYP1A1, CYP1B1, and COMT polymorphisms. Adjusted odds ratios (aORs) and 95% confidence intervals (95% CIs) were estimated by conditional logistic regression. A strong protective dose-dependent effect of energy-adjusted DISI on breast cancer was found in both pre- and postmenopausal women (P(trend)??1, OR 95% CIs exclude 1). In premenopausal women, only carrying CYP1B1 Leu/Leu was associated with breast cancer risk (aOR?=?2.05, 95% CI: 1.11-3.79). Carrying CYP1A1 Val/Val was related to breast cancer risk only among all women. A stratified analysis was performed at two levels of energy-adjusted DISI, with wildtype homozygous genotypes and low energy-adjusted DISI as the reference. In the high energy-adjusted DISI subgroup, carrying the CYP1B1 Leu/Leu genotype did not affect breast cancer risk in either all women or in the menopausal subgroups, compared with the reference. Overall, in Han Chinese women, carrying CYP1A1 Val/Val and COMT Met/Met appears to be associated with breast cancer risk, especially in postmenopausal women. CYP1B1 susceptible genotypes (Val/Leu or Leu/Leu) also contribute to increased breast cancer risk, regardless of menopausal status, but high soy isoflavone intake may reduce this risk.     

Leucocyte Ascorbic Acid Levels and Vitamin C Intake in Older People

Leucocyte ascorbic acid (L.A.A.) levels and vitamin C intake were measured in a random sample of men and women aged 62-94 years. L.A.A. distributions are positively skewed but log normal. L.A.A. mean values show no age difference in men but are significantly lower in older women. The mean value for all women (23·88μg/10⁸ cells) is significantly higher than that for all men (18·11 μg/10⁸ cells). L.A.A. values are significantly higher in both sexes in the six months July to December. Vitamin C intake distributions are positively skewed but not improved by log transformation. No significant age or sex differences were found except that a significantly greater proportion of men over than of those under 70 years have intakes less than 30 mg daily. Mean intake is significantly higher in men but not in women in the six months April to September, though in both sexes a significantly greater proportion have intakes less than 30 mg daily in October to March compared with April to September. Fifty per cent. of men and 58% of women have intakes less than 30 mg daily, 23·6% of men and 28·1% of women have intakes less than 20 mg daily, and 4·7% of men and 3% of women have intakes less than 10 mg daily. These percentages increase during the winter. A moderate correlation is present between vitamin C intake and L.A.A. level. L.A.A. levels increase in parallel with but lag behind seasonal increases in vitamin C intake.     

Determining human dietary requirements for boron

A dietary requirement is defined as the lowest continuing intake of a nutrient that for a specified indicator of adequacy, will maintain a defined level of nutriture in an individual. An essential dietary component is one that the body cannot synthesize in sufficient quantities to maintain health. Recommended dietary allowances (RDAs) are based on estimates of the dietary requirements, and are designed to prevent deficiency diseases and promote health through an adequate diet. In 1996, the Food and Nutrition Board (FNB) began a revision process of the RDAs using as criteria specific indicators of adequacy and functional end points for reducing the risk of chronic disease. Boron (B) is a dietary component, and evidence from animal studies indicates that it is a dietary essential; it cannot be synthesized in tissues, and organisms exposed to very low levels of B show developmental defects. In humans, there is evidence of homeostatic regulation of B and an interrelationship with bone metabolism. To understand better the relationship between dietary B and B homeostasis, we measured the dietary B intake and urinary B losses in seven male participants of a controlled metabolic study of Zn homeostasis. Average dietary B intake for the repeated menu days, days 1, 2, and 3, was 4.56, 1.87, and 4.75 mg/d, respectively. Urinary B excretion during the 42-d collection period averaged 3.20 ± 0.41 mg/d. When dietary B was low, urinary B loss (2.92 mg/d) was significantly lower than when B intake was higher (3.15 and 3.54 mg/d). Our study showed that urinary B excretion changes rapidly with changes in B intake, indicating that the kidney is the site of homeostatic regulation. To enable establishment of a dietary requirement for B in the future, further research of homeostatic regulation and functional markers of B metabolism need to be performed, followed by epidemiological studies to identify health conditions associated with inadequate dietary B.     

Consumption of Calcium-Fortified Cereal Bars to Improve Dietary Calcium Intake of Healthy Women: Randomized Controlled Feasibility Study

Calcium is an important structural component of the skeletal system. Although an adequate intake of calcium helps to maintain bone health and reduce the risk of osteoporosis, many women do not meet recommended daily intakes of calcium. Previous interventions studies designed to increase dietary intake of women have utilized primarily dairy sources of calcium or supplements. However, lactose intolerance, milk protein allergies, or food preferences may lead many women to exclude important dairy sources of dietary calcium. Therefore, we undertook a 9 week randomized crossover design trial to examine the potential benefit of including a non-dairy source of calcium in the diet of women. Following a 3 week run-in baseline period, 35 healthy women > 18 years were randomized by crossover design into either Group I or Group II. Group I added 2 calcium-fortified cereal bars daily (total of 400 mg calcium/day) (intervention) to their usual diet and Group II continued their usual diet (control). At the end of 3 weeks, diets were switched for another 3 weeks. Intakes of calcium and energy were estimated from 3-day diet and supplemental diaries. Wilcoxon signed-rank tests were used for within group comparisons and Mann Whitney U tests were used for between group comparisons of calcium and energy intake. Dietary calcium was significantly higher during intervention (1071 mg/d) when participants consumed 2 calcium-fortified cereal bars daily than during the baseline (720 mg/d, P <0.0001) or control diets (775 mg/d, P = 0.0001) periods. Furthermore, the addition of 2 calcium-fortified cereal bars daily for the 3 week intervention did not significantly increase total energy intake or result in weight gain. In conclusion, consumption of calcium-fortified cereal bars significantly increased calcium intake of women. Further research examining the potential ability of fortified cereal bars to help maintain and improve bone health of women is warranted.

Trial Registration

ClinicalTrials.gov NCT01508689     

The effect of boron supplementation on its urinary excretion and selected cardiovascular risk factors in healthy male subjects

Boron (B) is an essential trace element for plants and its interrelationship with mineral and bone metabolism and endocrine function in humans has been proposed. Relatively little is known about the occurrence of B in the food chain and hence a biomarker which reflects its intake is required. Two studies were carried out to quantify the urinary B concentration of subjects consuming their habitual diet and the effect of supplementation. In addition, the effect of supplementation on plasma lipoprotein cholesterol concentrations and susceptibility to oxidation and plasma steroid hormones were determined. Boron excretion, obtained on two different occasions from 18 healthy male subjects, was found to be in the range 0.35–3.53 mg/day, with no significant difference between the two occasions. Supplementation with 10 mg B/d for 4 wk resulted in 84% of the supplemented dose being recovered in the urine. Plasma estradiol concentrations increased significantly as a result of supplementation (51.9±21.4 to 73.9±22.2 pmol/L;p<0.004) and there was a trend for plasma testosterone levels to be increased. However, there was no difference in plasma lipids or the oxidizability of low-density lipoprotein Our studies suggest that the absorption efficiency of B is very high and estimation of the urinary B concentration may provide a useful reflection of B intake. In addition, the elevation of endogenous estrogen as a result of supplementation suggests a protective role for B in atherosclerosis.     

Zinc and copper concentrations in serum from Spanish women during pregnancy

A cross-sectional study of serum zinc (Zn) and copper (Cu) levels in 31 healthy pregnant women and 51 healthy, nonpregnant controls living in the Mediterranean area of Granada, Spain, was performed. The subjects were divided into two groups: Group A, consisted of pregnant women in three categories according to the trimester of pregnancy, and Group B consisted of nonpregnant women acting as controls. In pregnant women, serum Zn levels were found from 0.300-1.340 mg/L and serum Cu from 0.936-2.304 mg/L, whereas in the nonpregnant women group, the mean serum levels were 0.947 ±0.265 mg/L for Zn and 1.092 ±0.365 mg/L for Cu. Serum Zn progressively decreased with gestation. Mean Zn levels were 0.829 ±0.253, 0.846 ±0.329, and 0.620 ±0.142 mg/L, corresponding to the first, second, and third trimesters of pregnancy, respectively. Serum Zn concentrations were significantly lower in pregnant women as compared to controls: 0.712 ±0.236 mg/L vs 0.947 ±0.265 mg/L, respectively (p < 0.05). In contrast, Cu levels increased with period of gestation from 1.053 ±0.498 mg/L in the first trimester to 1.616 ±0.304 mg/L in the second and 1.689 ±0.344 mg/L in the third. Serum Cu levels in the second and third trimesters of pregnancy were significantly higher (p < 0.05) than those determined during the first trimester and for nonpregnant controls. Both Zn and Cu during pregnancy did not appear to be dependent on the subject’s age (p > 0.05).     

Effect of dietary boron on mineral, estrogen, and testosterone metabolism in postmenopausal women

A study was done to examine the effects of aluminum, magnesium, and boron on major mineral metabolism in postmenopausal women. This communication describes some of the effects of dietary boron on 12 women between the ages of 48 and 82 housed in a metabolic unit. A boron supplement of 3 mg/day markedly affected several indices of mineral metabolism of seven women consuming a low-magnesium diet and five women consuming a diet adequate in magnesium; the women had consumed a conventional diet supplying about 0.25 mg boron/day for 119 days. Boron supplementation markedly reduced the urinary excretion of calcium and magnesium; the depression seemed more marked when dietary magnesium was low. Boron supplementation depressed the urinary excretion of phosphorus by the low-magnesium, but not by the adequate-magnesium, women. Boron supplementation markedly elevated the serum concentrations of 17 beta-estradiol and testosterone; the elevation seemed more marked when dietary magnesium was low. Neither high dietary aluminum (1000 mg/day) nor an interaction between boron and aluminum affected the variables presented. The findings suggest that supplementation of a low-boron diet with an amount of boron commonly found in diets high in fruits and vegetables induces changes in postmenopausal women consistent with the prevention of calcium loss and bone demineralization.     

Serum zinc levels in healthy subjects from southeastern Spain

The serum zinc (Zn) concentrations of 80 healthy subjects (48 male, 32 female) from southeastern Spain were determined by atomic absorption spectrometry. The samples were digested by heating in a 4:1 mixture of nitric and perchloric acids. The concentration of Zn was determined against a Contox Trace Metal Serum Control Panel A standard reference. Zn concentrations in the standard were found to be 2.332 ±0.489 mg/L, with a mean recovery of 102.7%. In the serum samples, the relative standard deviation was <6% for the range of concentrations determined: 0.420-1.540 mg/L for women (mean value 0.947 ±0.265 mg/L) and 0.490-1.480 mg/L for men (mean value 0.951 ±0.243 mg/L). In healthy subjects, no statistically significant differences were observed in the Zn levels with respect to their sex (p > 0.05) or the location where they lived (mountainous vs coastal zones). It is concluded that the dietary Zn intake and Zn status for healthy adults in this region of Spain are within normal values.     

建鲤和异育银鲫摄食不同质量饲料时的氮收支和能量收支比较

实验探讨了建鲤和异育银鲫摄食低质和高质饲料时氮和能量的收支情况.低质饲料以豆粕为主要蛋白源,饲料蛋白含量为33.91%,高质饲料以鱼粉为主要蛋白源,饲料蛋白含量为45.59%.55d的生长结果显示,氮收支和能量收支受到饲料质量和鱼类种类的显著影响:摄食低质饲料时,建鲤的生长氮和生长能比例显著低于异育银鲫,排泄氮、排泄能和代谢能比例显著高于异育银鲫;摄食高质饲料时,两种鱼的氮收支和能量收支无显著差异;建鲤的氮收支和能量收支受饲料质量的显著影响,摄食低质饲料时,其生长氮和生长能比例均显著低于摄食高质饲料时,而排泄氮、粪能和代谢能比例均显著高于摄食高质饲料时;异育银鲫的氮收支、生长能和代谢能比例不受饲料质量的显著影响.结果表明,在低质饲料条件下,建鲤利用氮和能量的能力弱于异育银鲫,在高质饲料条件下,两种鱼没有显著差异.与异育银鲫相比,建鲤利用氮和能量的能力受饲料质量的影响更为显著.       

Distribution of lead in human milk fractions

The purpose of this study was to determine the concentration and distribution of lead, calcium, iron, zinc, and copper in major fractions (fat, casein, whey) of mature milk from 38 nursing adult women with low environmental lead exposure. The potential associations between milk lead and maternal blood lead and between milk and blood lead and essential mineral data (nutritional status, dietary intake, and milk concentration) were investigated. Maternal blood lead (geometric mean, 60 μg/L) was negatively associated, although modestly, with dietary calcium intake (r=−0.32, p=0.02). Lead in whole milk (geometric mean, 1.2 μg/L) was positively associated with calcium in whole milk (r=0.56, p=0.005). Distribution of lead in milk fractions was 63%, 28%, and 9%, in whey, fat, and casein, respectively. Milk distribution of essential minerals was 67–76%, 17–18%, and 7–17% in whey, fat, and casein, respectively. Lead in milk whey was positively associated with lead in maternal blood (r=0.49, p=0.02). However, milk lead was not affected by nutritional status, dietary intake, and milk composition of the essential minerals. The high percentage of lead in the milk whey fraction, as seen for the essential minerals, suggests that most lead in human milk is bioavailable to the infant.     

Intestinal absorption of calcium from yogurt in lactase-deficient subjects.

Fractional intestinal absorption of calcium (FACa) was measured using radioactive calcium and 200 mg of calcium carrier provided either by yogurt or by CaCl2 in 7 lactase-deficient (L(-] and 7 normal (L(+] subjects. During the control period prior to yogurt consumption, mean calcium intake was 819 mg per day in L(-) and 931 mg per day in L(+) subjects (NS). In both groups of subjects yogurt increased FACa from 20.8 +/- 3.9% to 26.9 +/- 7.2% (P = 0.065) in L(+) subjects and from 20.2 +/- 5.6% to 23.5 +/- 6.4% (P = 0.050) in L(-) subjects. The significant increase in FACa observed in L(-) subjects indicates that yogurt, which is an autodigesting source of lactose, does not impair calcium absorption. FACa increase could reflect the lower dietary calcium intake in L(-) subjects when compared with L(+) subjects, due to avoidance of milk and non-fermented dairy products which could cause intestinal discomfort. It is concluded that yogurt is a well-tolerated and efficient source of calcium in subjects with lactase deficiency.