Increased Expression of PHGDH Under High-Selenium Stress In Vivo.

The purpose of this study is to explore the glycolytic remodeling under high-selenium (Se) stress. Three groups of male C57BL/6J mice were fed on diets with different Se contents (0.03, 0.15, and 0.30 mg Se/kg). Glucose tolerance test (GTT) and insulin tolerance test (ITT) were measured at the third month. Mice were killed at the fourth month. Plasma, liver, and muscle tissues were fetched for biochemistry and Se analysis. The expressions of insulin signaling pathway (PI3K-AKT-mTOR), glutathione peroxidase 1 (GPX1), selenoprotein N (SELENON), 3-phosphoglycerate dehydrogenase (PHGDH), serine hydroxymethyltransferases 1 (SHMT1), 5,10-methylenetetrahydrofolate reductase (MTHFR), and methionine synthase (MS) were analyzed by western blotting (WB) in liver and muscle tissues. The results of GTT and ITT showed that glucose tolerance and insulin tolerance were both abnormal in the 0.03 mg Se/kg and 0.3 mg Se/kg groups. Se concentrations in plasma, liver, and muscle of 0.03 mg Se/kg group were significantly lower than that of 0.15 mg Se/kg and 0.30 mg Se/kg groups (p < 0.05 or p < 0.01). The expressions of P-Akt (Thr-308) in muscle (p < 0.05) and PI3K and mTOR in liver (p < 0.001) of 0.30 mg Se/kg group were downregulated. The expressions of GPX1 in liver and muscle (p < 0.05 and p < 0.001), SELENON in muscle (p < 0.05), PHGDH in liver and muscle (p < 0.05), and SHMT1 (p < 0.05), MTHFR (p < 0.001), and MS (p < 0.001) in muscle of 0.3 mg Se/kg group were upregulated. The de novo serine synthesis pathway (SSP) was found to be activated in liver and muscle tissues of mice with a high-Se diet for the first time.

Effect of N, N-Dimethylglycine on Homocysteine Metabolism in Rats Fed Folate-Sufficient and Folate-Deficient Diets.

OBJECTIVE: This study aimed to investigate the effects of N,N-dimethylglycine (DMG) on the concentration and metabolism of plasma homocysteine (pHcy) in folate-sufficient and folate-deficient rats. METHODS: In this study, 0.1% DMG was supplemented in 20% casein diets that were either folate-sufficient (20C) or folate-deficient (20CFD). Blood and liver of rats were subjected to assays of Hcy and its metabolites. Hcy and its related metabolite concentrations were determined using a liquid chromatographic system. RESULTS: Folate deprivation significantly increased pHcy concentration in rats fed 20C diet (from 14.19 ± 0.39 µmol/L to 28.49 ± 0.50 µmol/L; P < 0.05). When supplemented with DMG, pHcy concentration was significantly decreased (12.23 ± 0.18 µmol/L) in rats fed 20C diet but significantly increased (31.56 ± 0.59 µmol/L) in rats fed 20CFD. The hepatic methionine synthase activity in the 20CFD group was significantly lower than that in the 20C group; enzyme activity was unaffected by DMG supplementation regardless of folate sufficiency. The activity of hepatic cystathionine ß-synthase (CBS) in the 20CFD group was decreased but not in the 20C group; DMG supplementation enhanced hepatic CBS activity in both groups, in which the effect was significant in the 20C group but not in the other group. CONCLUSION: DMG supplementation exhibited hypohomocysteinemic effects under folate-sufficient conditions. By contrast, the combination of folate deficiency and DMG supplementation has deleterious effect on pHcy concentration.

Low-Se Diet Can Affect Sperm Quality and Testicular Glutathione Peroxidase-4 activity in Rats.

This study aimed to observe the influence of selenium (Se) deficiency on sperm quality and selenoprotein expression in rats. Four-week male Wista rats were randomly divided into three groups: Se-A, Se-L, and Se-D (respectively for Se- adequate, low, and deficient group). After 9 weeks, the rats were sacrificed by anesthesia, with the cauda epididymidis quickly fetched for sperm count, motility, and deformity. Meanwhile the blood, liver, brain, heart, and testis were collected for Se and biochemical analysis. It was found that the rats in Se-D had poor growth, while the Se concentrations in blood, liver, and heart for Se-D decreased significantly, compared with Se-A and Se-L (p < 0.01). But no significant difference was observed in testis and brain and also no statistical significance for sperm count. The sperm motility for Se-A (63.07%) was significantly higher than Se-L (53.91%) and Se-D (54.15%). Deformities were observed in both Se-L and Se-D. Both glutathione peroxidases (GPxs) and selenoprotein-P (SEPP1) levels in plasma and tissues of Se-D were significantly lower than those of Se-A and Se-L (p < 0.01). The SEPP1 levels in heart and brain of Se-L were lower than Se-A (p < 0.01). There was no statistical difference for GPx1 between Se-A and Se-L. The GPx4 level in testis of Se-L was lower than Se-A (p < 0.05). However, the SEPP1 in plasma, liver, testis, and the GPx3 level in plasma of Se-L were higher than those of Se-A (p < 0.05 or p < 0.01). Our results show that dietary Se deficiency could reduce GPx4 and SEPP1 expression in testis, which further influence sperm motility and may cause sperm deformity. Selenoprotein expression in some tissues of Se-L was higher than that of Se-A, but sperm quality and GPx4 expression in testis were not improved for Se-L. Low active pseudoselenoproteins might be synthesized in low-Se condition. The underlying mechanism needs to be further investigated.

Breast milk selenocystine as a biomarker for selenium intake in lactating women at differential geographical deficiency risk in China.

BACKGROUND AND OBJECTIVES: A reliable biomarker for optimal selenium (Se) intake in lactating women is not currently available. METHODS AND STUDY DESIGN: Daily dietary Se intake in lactating women was calculated from a 24-hour meal record survey for over 3 days. Se levels in plasma and breast milk were measured through inductively coupled plasma mass spectrometry. Plasma selenoprotein P 1 levels and glutathione peroxidase 3 activity were measured using an enzyme-linked immunosorbent assay. Ultra-performance liquid chromatography-tandem mass spectrometry was used to analyze proteinaceous Se species in enzymatically digested breast milk. RESULTS: Dietary Se intakes of lactating women from Liangshan, Beijing, and Enshi were 41.6±21.2 ng/d, 51.1±22.6 ng/d, and 615±178 ng/d, respectively (p<0.05). The Se levels in the blood and breast milk were significantly associated with the dietary Se intake (p<0.05). The proteinaceous Se species in breast milk were SeMet and SeCys2. The levels of SeMet in the lactating women from Liangshan, Beijing, and Enshi were 3.31±2.44 ng Se/mL, 7.34±3.70 ng Se/mL, and 8.99±9.64 ng Se/mL, while that of SeCys2 were 13.7±12.0 ng Se/mL, 35.6±20.9 ng Se/mL, and 57.4±13.2 ng Se/mL, respectively. Notably, the concentration of SeCys2, the metabolite of unstable SeCys, reached a saturation platform, whereas no similar phenomenon were found for the total Se SeMet from Secontaining proteins. CONCLUSIONS: SeCys2 in breast milk is a potential biomarker for determining the optimal Se intake in lactating women.

Pharmacokinetics and metabolism of icaritin in rats by UPLC-MS/MS.

Icaritin (ICT) has distinct bioactivities, especially known for its beneficial effects on bone-related degenerative disorders; however, its pharmacokinetic properties remain unknown. A novel developed UPLC-MS/MS method for the determination of ICT and its main metabolite glucuronidated icaritin (GICT) was firstly applied to pharmacokinetic and metabolism studies of ICT in female rats, which were intraperitoneally given 40 mg/kg ICT. Following the protein precipitation of plasma samples with acetonitrile, ICT and GICT were separated on a C18 column using gradient elution mode and quantified in the multiple reaction monitoring mode. The linearities were acceptable for ICT (r = 0.9960) and GICT (r = 0.9968), and the lower limit of quantification values was 0.5 and 5 ng/ml, respectively. The accuracy fell in the range of 92.0%-103.1% and precisions were within 9.5%. Good linearity, accuracy, precision, and recovery were achieved for the UPLC-MS/MS method. ICT was predominantly and rapidly biotransformed to GICT which was slowly eliminated in vivo with a terminal half-life value of 4.51 hr. Pharmacokinetics of pure ICT eliminated biotransformation interference of Epimedium extract and disclosed genuine pharmacokinetic manner of ICT, as well as firstly elucidated low concentration and bioavailability of ICT in rat plasma.

Selenium in infant formula milk.

Formula-based animal milk is an alternative source of infant nutrition in many cases when breastfeeding is unacceptable or inaccessible; however, these replacements often have low selenium levels. The composition of infant formula milk should be as close as possible to that of human breast milk, both in content and chemical speciation. Selenium is an essential trace element for infants. Generally, human breast milk is the ideal food to ensure adequate infant Se intake. However, to date, sodium selenite or sodium selenate has been used as selenium supplementation in infant formula milk in most countries. This inorganic Se, which is not a natural component of food, may not be the optimal speciation for Se supplementation in infant formula milk. Advances in speciation in foods, especially in animal milk, suggest that future proposals for selenium speciation in human breast milk can lead to discussions regarding the most favorable methods of selenium supplementation in infant formula milk.

The Synergistic Effect of Serine with Selenocompounds on the Expression of SelP and GPx in HepG2 Cells.

We explored the synergistic effect of serine combined with several selenocompounds or used alone on the expression of selenoprotein P (SelP) and glutathione peroxidase (GPx) in this study. We first compared the SelP and GPx expression difference between HepG2 and Hela cells treated with serine and finally chose HepG2 as experimental cell. In the serine-used-alone experiment, three kinds of selenium nutritional models (low-, adequate-, and high-selenium) were established and serine was 10 times gradient diluted (0.01 to 100 µmol/L). In the combined experiment, the selenocompound doses were set as 0.01, 0.1, and 1 µmol Se/L and serine was set according to its molar ratio with the selenocompounds. We found that SelP and GPx concentrations in the low-, adequate-, and high-selenium models increased following with serine dose. When the concentration of sodium selenite and SeMet was 1 µmol Se/L while MeSeCys was 0.1 and 1 µmol Se/L, SelP concentrations for serine combined with selenocompounds groups were significantly higher than that of selenocompounds used alone. When the concentration of sodium selenite was 0.1 µmol Se/L, SeMet was 0.1 and 1 µmol Se/L while MeSeCys was 0.01 and 1 µmol Se/L, GPx concentrations for serine combined with selenocompounds groups were significantly higher than that of selenocompounds used alone. Our preliminary result indicated the beneficial effect of serine on the expression of SelP and GPx, which suggested that it might be a candidate for combined selenium supplement.

The effects of different levels of calcium supplementation on the bone mineral status of postpartum lactating Chinese women: a 12-month randomised, double-blinded, controlled trial.

Increasing dietary Ca intake may prevent the excessive mobilisation of bone mineral in nursing mothers. We aimed to investigate whether higher Ca intake could positively modulate the bone mineral changes in Chinese postpartum lactating women. The study was a 12-month randomised, double-blinded, parallel group trial conducted over 12 months. A total of 150 postpartum women were randomly selected to receive either 40 g of milk powder containing 300 mg of Ca and 5 µg of vitamin D (Low-Ca group) or same milk powder additionally fortified with 300 mg of Ca (Mid-Ca group) or 600 mg of Ca (High-Ca group). Bone mineral density (BMD) for the whole body, the lumbar spine, the total left hip and its sub-regions was measured using dual-energy X-ray absorptiometry. A total of 102 subjects completed the whole trial. The duration of total lactating time was 7·9 (SD 2·8) months on average. The intention-to-treat analysis yielded the following mean percentage changes in BMD for the whole body, the lumbar spine and the total left hip, respectively: -0·93 (SD 1·97), 2·11 (SD 4·90) and -1·60 (SD 2·65)% for the Low-Ca group; -0·56 (SD 1·89), 2·21 (SD 3·77) and -1·43 (SD 2·30)% for the Mid-Ca group; and -0·44 (SD 1·67), 2·32 (SD 4·66) and -0·95 (SD 4·08)% for the High-Ca group. The differences between the groups were not statistically significant (P: 0·5-0·9). The results of the complete case analysis were similar. In sum, we found no significant differences in the bone mineral changes from baseline to 12 months in postpartum lactating women consuming milk powder fortified with different levels of Ca.

Suppression effects of betaine-enriched spinach on hyperhomocysteinemia induced by guanidinoacetic acid and choline deficiency in rats.

Betaine is an important natural component of rich food sources, especially spinach. Rats were fed diets with betaine or spinach powder at the same level of betaine for 10 days to investigate the dose-dependent effects of spinach powder supplementation on hyperhomocysteinemia induced by guanidinoacetic acid (GAA) addition and choline deprivation. The GAA-induced hyperhomocysteinemia in rats fed 25% casein diet (25 C) was significantly suppressed by supplementation with betaine or spinach, and it was completely suppressed by taking 11.0% spinach supplementation. The choline deprivation-induced enhancement of plasma homocysteine concentration in rats fed 25% soybean protein diet (25S) was markedly suppressed by 3.82% spinach. Supplementation with betaine or spinach partially prevented the effects of GAA on hepatic concentrations of methionine metabolites. The decrease in activity of betaine-homocysteine S-methyltransferase (BHMT) and cystathionine ß-synthase (CBS) in GAA-induced hyperhomocysteinemia was recovered by supplementation with betaine or spinach. Supplementation with betaine or spinach did not affect BHMT activity, whereas it partially restored CBS activity in choline-deprived 25S. The results indicated that betaine or spinach could completely suppress the hyperhomocysteinemia induced by choline deficiency resulting from stimulating the homocysteine removal by both remethylation and cystathionine formation.

Calcium supplementation and bone mineral accretion in Chinese adolescents aged 12-14 years: a 12-month, dose-response, randomised intervention trial.

A 12-month, dose-response, randomised, intervention trial was conducted to determine adequate Ca intake levels for Chinese adolescents by investigating the effect of Ca supplementation on bone mineral accretion. A total of 220 Han adolescents (111 girls and 109 boys) aged 12-14 years were recruited. All subjects were randomly divided into three groups. The bone mineral content (BMC) and bone mineral density (BMD) of the whole body, lumbar spine (L1-L4), left hip and femoral neck were measured by dual-energy X-ray absorptiometry. Girls in the high-Ca group (actual Ca intake: 1243 (sd 193) mg/d) exhibited greater increases in the femoral neck BMC compared with those in the low-Ca group (9·7 v. 6·4 %, P =0·04) over the 1-year intervention period. The increases in femoral neck BMC were greater in boys in the high-Ca and medium-Ca groups (actual Ca intake: 985 (sd 168) mg/d) than in those in the low-Ca group (15·7 v. 11·7 %, P =0·03; 15·8 v. 11·7 %, P =0·03). Ca supplementation had significant effects on the whole-body BMC and BMD in subjects with physical activity levels>34·86 metabolic equivalents and on the spine BMD and BMC and BMD of most sites in subjects with Tanner stage < 3. Increasing Ca intake levels with Ca supplementation enhanced femoral neck mineral acquisition in Chinese adolescents. Furthermore, high physical activity levels and low Tanner stage appeared to significantly contribute to the effect of Ca supplementation on bone mass. Whether this is a lasting beneficial effect leading to the optimisation of peak bone mass needs to be determined in other long-term prospective studies.

Effects of milk salt supplementation on bone mineral gain in pubertal Chinese adolescents: a 2-year randomized, double-blind, controlled, dose-response trial.

BACKGROUND/OBJECTIVE: Adequate calcium intakes may enhance bone mineral accumulation during childhood. Little is known about the optimal calcium intake in Chinese adolescents. We examined the effects of three levels of calcium intake on bone mineral accretion in adolescents. METHODS: This was a 2-year randomized, double-blind, controlled trial. The subjects were randomly assigned to receive 40 g of milk powder containing 300 mg of calcium and 200 IU of vitamin D (Low-Ca group), or same milk powder additionally fortified with 300 mg of calcium (Mid-Ca group) or 600 mg of calcium (High-Ca group) for 2 years. The subjects' bone mineral density (BMD) and bone mineral content (BMC) at the total body, lumbar spine and left hip were determined by dual-energy X-ray absorptiometry at baseline and after the second year of treatment. Of the 111 girls and 109 boys (aged 12-14 years) enrolled, 91 girls and 91 boys completed the trial. RESULTS: The girls in the High-Ca group (1,110 mg/d) had 2.3%, 2.7% and 2.6% greater BMD accretion at the total hip, femoral neck and shaft (P<0.05) but not at total body less head and spine than those in the Low-Ca group (655 mg/d). A significant effect of higher calcium intake was also observed for percentage change of size-adjusted BMC at femur neck (P=0.047). Bonferroni tests indicated no significant differences in the percentage changes in BMD, BMC or size-adjusted BMC between the Mid- and Low-Ca groups and between the High- and Mid-Ca groups. Extra calcium had no observable additional effect in the boys (P>0.05). CONCLUSION: An intake of 1000 mg/d or more might be helpful in maximizing bone mineral accretion in the hip for girls. But further large studies are required to identify its long-term effects and the optimal calcium intake for boys.

Fruit and vegetable intake and bone mass in Chinese adolescents, young and postmenopausal women.

OBJECTIVE: Previous studies showed an inconsistent association of fruit and vegetable consumption with bone health. We assessed the associations in Chinese adolescents, young and postmenopausal women. DESIGN: A cross-sectional study conducted in China during July 2009 to May 2010. SETTING: Bone mineral density (BMD) and content (BMC) at the whole body, lumbar spine and left hip were measured with dual-energy X-ray absorptiometry. Dietary intakes were assessed using an FFQ. All these values were separately standardized into Z-scores in each population subgroup. SUBJECTS: One hundred and ten boys and 112 girls (11-14 years), 371 young women (20-34 years, postpartum within 2 weeks) and 333 postmenopausal women (50-70 years). RESULTS: After adjustment for potential covariates, analysis of covariance showed a significantly positive association between fruit intake and BMD and BMC in all participants combined (P-trend: < 0.001 to 0.002). BMD Z-score increased by 0.25 (or 2.1 % of the mean), 0.22 (3.5 %), 0.23 (3.0 %) and 0.25 (3.5 %), and BMC Z-score increased by 0.33 (5.7 %), 0.25 (5.8 %), 0.34 (5.9 %) and 0.29 (4.7 %), at the total body, lumbar spine, total hip and femoral neck in participants belonging to the top tertile compared with the bottom tertile of fruit intake (all P < 0.05), respectively. There was no significant association between vegetable intake and bone mass at all bone sites studied except for total body BMD (P = 0.030). Relatively more pronounced effects were observed in boys and postmenopausal women. CONCLUSION: Our findings add to the existing evidence that fruits and vegetables may have a bone sparing effect.

Relatively high bone mineral density in Chinese adolescent dancers despite lower energy intake and menstrual disorder.

OBJECTIVE: The effect of dietary restriction, intense exercise and menstrual dysfunction on bone mineral density remains controversial. The aim of this study was to assess the skeletal health status and relationship between bone mineral density and nutrient intake, menstrual status, estrogen level and other factos in Chinese adolescent dancers. METHODS: Sixty dancers and 77 healthy controls underwent measurements of bone density, body composition, and estrogen level. Nutrient intake, menstrual status and physical activity were assessed with questionnaires. The correlation between these factors were analyzed. RESULTS: The dancers under study had a significantly lean body mass index (18.3 +/- 1.4 kg/m2 vs. 21.7 +/- 3.1 kg/m2), lower percentage of body fat (0.25 +/- 0.05 vs. 0.34 +/- 0.04) and later age at menarche (14.0 +/- 0.9 y vs. 13.0 +/- 1.3 y), and the estrogen level, daily calorie and fat intake in them were also lower than in the controls. All the dancers undertook intensive physical activity every day and up to 69% of them suffered from irregular menarche. Yet they had relatively high BMD and BMC of the total body and legs than the controls after adjusting for BMI and age. Site-specific BMD was positively correlated to BMI, body composition and training hours per week and negatively correlated to the age at menarche and menstrual frequency. CONCLUSIONS: The relatively high BMD and BMC of the dancers at the total body and legs were probably caused by high levels of weight-bearing physical activity. To ameliorate disordered eating, especially low energy intake might be helpful to prevent the Triad and to improve the bone health in adolescent dancers.

[Relationship between estrogen receptor gene Px haplotype and the effect of calcium and soy isoflavone supplementation on bone mineral density of Chinese postmenopausal women].

OBJECTIVE: To investigate the relationship between estrogen receptor gene Px haplotype and the effect of calcium and soy isoflavone supplementation on bone mineral density (BMD) of Chinese postmenopausal women. METHODS: It was a randomly controlling test for 12 months. The Pvu II and Xba I polymorphisms of ER-alpha gene were detected by using restriction fragment length polymorphisms (RFLP) in 691 Chinese postmenopausal women, aged 45-65 years. In 497 carriers of definitive Pvu II-Xba I haplotype, 93 subjects were chosen randomly. BMD was measured by dual energy X-ray absorptiometry (DXEA). According to BMD T score in any skeleton site of 81 subjects at baseline, 29 subjects with T > or = -1.5 were grouped into observation group, and 52 subjects with T < -1.5 were randomly assigned into two intervention groups and received either a 100 mg soy isoflavone and 440 mg Ca and 100 IU VD supplement/d (n = 26) or 440 mg Ca and 100 IU VD supplement/d (n = 26). BMD of the whole body, lumber (L2-L4), and hip were measured at baseline and after 12 months. RESULTS: After one year fellow-up, the BMD at L2-L4, femur neck site and whole body were significantly decreased as compared with those of baseline (P < 0.05, change percent of BMD as follows: -3.31%, -3.09%, -1.88%) in observation group, and the whole body BMD was significantly lower at 12 month than that at baseline in subjects with Px haplotype (percent change was -2.44%, P < 0.05), but no difference was found in subjects without Px haplotype. Whole body and femur neck BMD were significantly decreased in both Ca group and Ca + soy isoflavone group, but no significant difference of change percent between two groups. There were no significant changes in L2-L4 and trochanter BMD irrespective of treatment. ER-alpha Px haplotype had no effect on the changes in BMD in both Ca group and Ca + soy isoflavone group. CONCLUSION: The rate of bone loss in Chinese postmenopausal women seems to haverelation to ER Px haplotype. Calcium supplementation for 1 year might lower the bone loss rate, but soy isoflavone supplementation for 1 year had notshowu no effects. The effect of supplementation had no relationship with ER Px haplotype.

[Study on the association between estrogen receptor-alpha gene polymorphisms and pubertal skeletal developmental status in China].

OBJECTIVE: To investigate the association between estrogen receptor-alpha (ER-alpha) gene polymorphisms, pubertal bone mineral density (BMD) and bone turnover markers, to better understand the frequencies of ER-a genotypes. METHODS: The ER-alpha Pvu II and Xba I genotypes were determined by PCR-RFLP in 158 healthy adolescent girls (12-14 years old) while BMD was measured by dual-energy X-ray absorptiometry (DEXA). The bone turnover markers (BAP, BGP, TRACP) and calcium adjust hormone (25-OH-VitD, E2) were detected by ELISA. The relationship among BMD, bone turnover markers, and polymorphisms of ER-a were examined. RESULTS: (1) Although the bone turnover markers had a trend in ER-alpha Pvu II genotypes as pp>PP>Pp but no significant difference was found (P > 0.05). There were no significant differences found among Xba I genotypes and between Px haplotype and non-Px haplotype. (2) No association was noticed between ER-a genotype and BMD at any site of the forearm and the whole body. Compared with non-Px haplotype, the Px haplotype had lower BMD, but there was no significant difference noticed (P > 0.05). CONCLUSION: ER-alpha gene Pvu II and Xba I polymorphism seemed not potentially influence on BMD and bone turnover markers in the pubertal girls in Beijing, suggesting that it might not be the major genetic factor regarding this population.

[Association of bone mineral density with gene polymorphisms and environmental factors in Chinese postmenopausal women].

OBJECTIVE: To investigate the relationship between bone mineral density (BMD) and polymorphisms of the eatrogen receptor (ER) and vitamin D receptor (VDR) in relation to some environmental factors. METHODS: Ninety postmenopausal Chinese rural women of Han population, aged 45 to 65, were voluntarily enrolled in this study. We conducted BMD measurement of the lumber spine and hip by dual energy X-ray absorptiometry (DXEA) and performed a questionnaire survey of diet intake and outside activity. The polymorphisms of ER gene and VDR gene were determined using polymerase chain reaction restriction fragment length polymorphism ( PCR-RFLP). RESULTS: There is no significant influence of ER Px haplotype on BMD in Chinese women. VDR Bsm I polymorphisms was associated with BMD at the lumbar spine and the BMD in the Bb genotype was lower than in the bb genotype (P < 0.05), but the significant difference was weakened after adjusting for confounding factors such as age height weight activity diet and menopause age. Women with the ER Px haplotype and VDR B allele genotype had lowest BMD at lumber (P < 0.05), but the difference of BMD became not significant after adjusting for confounding factors such as age height weight activity diet and menopause age. Diet calcium, protein, carbohydrate and energy simply related to BMD. Stepwise multiple regression analysis showed that age and body weight were strong predictor of BMD in postmenopausal women. Other significant predictors were menopausal age and carbohydrate at lumber spine and menopausal age at femur neck. CONCLUSION: BMD was not associated with ER genotype but with VDR Bsm I polymorphism. Environmental factors influence the relationship between gene polymorphism and BMD.

[Relationship between the absorption of dietary calcium and the Fok I polymorphism of VDR gene in young women].

OBJECTIVE: To investigate the relationship between the absorption of dietary calcium and VDR (Vitamin D(3) receptor, VDR) gene RFLPs in Chinese young women with representative diets. METHODS: Forty subjects were selected from three hundred young female students aged 18 - 23 years old. After identifying the VDR gene Fok I RFLPs, the subjects were given the representative diets during the 3-day adaptation period and the 12-day metabolism period. The copy food and drinking for measurement of nutrients and also the complete feces each day were collected. The dietary calcium absorption of each subject was examined and calculated. RESULTS: As expected, the intake of dietary calcium in subjects is close to the results set by the of National Nutrition Investigation in 1992 (from young women at 17 year old) or the daily reference intake (DRI) for adult woman; the difference of the absorption of dietary calcium among VDR gene RFLPs in young women was observed: ff < Ff < FF, (28.7 +/- 10.5)%, (30.4 +/- 15.9)% and (40.6 +/- 11.0)% respectively; only significant difference between FF genotype and Ff genotype, P < 0.05. CONCLUSION: Our results were consistent with those gained from the previous studies on children about the relationship between the absorption of dietary calcium and VDR (Vitamin D(3) receptor, VDR) gene RFLPs, and now it might occur in young women. Further studies need to be taken by using stable isotope and increasing subjects in young women.

[Fractional utilization of reduced iron powder in Chinese child bearing age women with dual stable isotopes].

OBJECTIVE: To study the utilization of reduced iron powder in child-bearing-age women with traditional Chinese food. METHODS: 20 health child-bearing-age women were randomly divided into two groups. With ferrous sulfate as control, the utilization of reduced iron was measured using dual stable isotopes. RESULTS: The fractional utilization of iron in ferrous sulfate was 5.8%, while in reduced iron powder was 2.1%. The rates of absorbed iron incorporated into hemoglobin were 70.1% and 91.3% respectively. The differences were statistic significant. CONCLUSION: With traditional Chinese food, the utilization of reduced iron in child-bearing-age women was 2.1%, and the rate of absorbed iron incorporated into red blood cells was 91.3%.