Associations between the dietary intake of antioxidant nutrients and the risk of hip fracture in elderly Chinese: a case-control study

Vitamin A - discovery, metabolism, receptor signaling and effects on bone mass and fracture susceptibility

The first evidence of the existence of vitamin A was the observation 1881 that a substance present in small amounts in milk was necessary for normal development and life. It was not until more than 100 years later that it was understood that vitamin A acts as a hormone through nuclear receptors. Unlike classical hormones, vitamin A cannot be synthesized by the body but needs to be supplied by the food as retinyl esters in animal products and ß-carotene in vegetables and fruits. Globally, vitamin A deficiency is a huge health problem, but in the industrialized world excess of vitamin A has been suggested to be a risk factor for secondary osteoporosis and enhanced susceptibility to fractures. Preclinical studies unequivocally have shown that increased amounts of vitamin A cause decreased cortical bone mass and weaker bones due to enhanced periosteal bone resorption. Initial clinical studies demonstrated a negative association between intake of vitamin A, as well as serum levels of vitamin A, and bone mass and fracture susceptibility. In some studies, these observations have been confirmed, but in other studies no such associations have been observed. One meta-analysis found that both low and high serum levels of vitamin A were associated with increased relative risk of hip fractures. Another meta-analysis also found that low levels of serum vitamin A increased the risk for hip fracture but could not find any association with high serum levels of vitamin A and hip fracture. It is apparent that more clinical studies, including large numbers of incident fractures, are needed to determine which levels of vitamin A that are harmful or beneficial for bone mass and fracture. It is the aim of the present review to describe how vitamin A was discovered and how vitamin A is absorbed, metabolized and is acting as a ligand for nuclear receptors. The effects by vitamin A in preclinical studies are summarized and the clinical investigations studying the effect by vitamin A on bone mass and fracture susceptibility are discussed in detail.

Diet-derived antioxidants and osteoporosis: A Mendelian randomization study

BACKGROUND

Antioxidants can prevent osteoporosis, but the association between serum antioxidants and the cause of osteoporosis remains unknown. We aimed to utilize Mendelian randomization (MR) to determine whether genetically predicted serum levels of diet-derived antioxidants can affect the risk of osteoporosis, to determine the effect of dietary supplementation of antioxidants.

METHODS

Genetic variants associated with diet-derived antioxidants were selected from the genome-wide association studies. A total of 12,946 osteoporosis cases and 506,624 healthy controls were obtained from UK Biobank (UKB) and Genetic Factors of Osteoporosis (GEFOS) consortia. We implemented a two-sample MR design and performed several sensitivity analyses to evaluate the causal relationship.

RESULTS

In UKB, the genetically predicted higher β-carotene (OR = 0.863, p = 7.37 × 10-6, power = 100%) and γ-tocopherol (OR = 0.701, p = 0.021, power = 5%) had an inverse relationship with osteoporosis. However, only the association of serum β-carotene passed FDR correction. In GEFOS, there were no significant diet-derived antioxidants. The direction of the association of β-carotene with osteoporosis (OR = 0.844, p = 0.106, power = 87%) was consistent with that in the UKB dataset. A fixed-effects meta-analysis confirmed that β-carotene (OR = 0.862, p = 2.21 × 10-6) and γ-tocopherol (OR = 0.701, p = 2.31 × 10-2) could decrease the risk of osteoporosis. To reduce exclusion limit bias, we used total body bone mineral density, lumbar spine bone mineral density and femoral neck bone mineral density as surrogates and found that the genetically elevated circulating β-carotene level could increase total body BMD (beta = 0.043, p-value = 8.26 x 10-5, power = 100%), lumbar spine BMD (beta = 0.226, p-value = 0.001, power = 100%) and femoral neck BMD(beta = 0.118, p-value = 0.016, power = 100%).

CONCLUSIONS

We observed that genetically predicted serum β-carotene could elevate BMD and prevent osteoporosis.

Association between dietary selenium intake and the prevalence of osteoporosis and its role in the treatment of glucocorticoid-induced osteoporosis

BACKGROUND

Long-term glucocorticoid therapy may lead to osteoporosis (OP). Selenium (Se) is an essential microelement for human health and bone health. This study evaluated the association between dietary Se intake and the prevalence of OP and further explored the potential therapeutic effect of Se on glucocorticoid-induced OP (GIOP) in vivo and in vitro.

METHODS

Data were collected from a population-based cross-sectional study conducted in our hospital. OP is diagnosed based on bone mineral density (BMD) measurements using compact radiographic absorptiometry. Dietary Se intake was assessed using a semi-quantitative food frequency questionnaire. The association between dietary Se intake and OP prevalence was analyzed by multivariable logistic regression. In animal experiments, male Sprague-Dawley rats were intramuscularly injected with dexamethasone (1 mg/kg) daily to induce GIOP, while different doses of Se were supplemented in rat drinking water for 60 d. BMD and biomechanical parameters of rat femur were measured. The histopathological changes of the femur were observed by HE staining, the number of osteoclasts was observed by TRAP staining, and OCN positive expression was detected by immunohistochemical staining. OPG, RANKL, Runx2, and BMP2 in rat femur were detected by Western blot. Bone turnover markers and oxidative stress markers were measured using commercial kits. MC3T3-E1 cells were induced to osteogenic differentiation, stimulated with DXM (100 μM), and/or treated with Se at different doses. Cell proliferation and apoptosis were assessed by CCK-8 and flow cytometry. ALP activity was detected by ALP staining and cell mineralization was observed by alizarin red staining.

RESULTS

Participants with lower dietary Se intake had higher OP prevalence. Se supplementation improved BMD, biomechanical parameters, and histopathological changes of the femur in GIOP rats. Se supplementation also suppressed DXM-induced changes in bone turnover- and oxidative stress-related markers. Under DXM conditions, Se treatment induced MC3T3-E1 cell proliferation, ALP activity, and mineralization.

CONCLUSION

Lower Dietary Se intake is associated with OP prevalence. Moreover, Se takes a position in bone protection and anti-oxidative stress in GIOP models. Therefore, Se may be a complementary potential treatment for GIOP.

Low levels of serum vitamin C in children with limb fractures: a case-control study

Introduction

The role of vitamin C in pediatric fractures has not received much attention, although it is known to be a factor in osteoporotic fractures in the elderly. This case-control study aimed to investigate the changes in serum vitamin C levels among children with limb fractures.

Methods

We recruited 325 children with and 316 children without limb fractures hospitalized between January 2021 and December 2021. Following admission, basic demographic data of all participants were collected, and fasting serum vitamin C levels were determined using ultra-high-performance liquid chromatography-tandem mass spectrometry.

Results

The mean age of the fracture group was 5.1 years (95% CI, 4.83-5.33). The serum vitamin C levels in the fracture group (4.48 µg/ml) were significantly lower than those in the control group (8.38 µg/ml) (p < 0.0001). Further subgroup analysis of the fracture group revealed that serum vitamin C levels decreased significantly after 4 years of age and there was a significant difference in the duration after injury between <6 and >6 h (p = 0.0224). Spearman's rank correlation coefficient suggested that age and vitamin C levels were negatively correlated in the fracture group.

Conclusion

In general, children with limb fractures had lower serum vitamin C levels, especially those aged 4 years and over.

The association between selenium and bone health: a meta-analysis

Aims

Previous studies have suggested that selenium as a trace element is involved in bone health, but findings related to the specific effect of selenium on bone health remain inconclusive. Thus, we performed a meta-analysis by including all the relevant studies to elucidate the association between selenium status (dietary intake or serum selenium) and bone health indicators (bone mineral density (BMD), osteoporosis (OP), or fracture).

Methods

PubMed, Embase, and Cochrane Library were systematically searched to retrieve relevant articles published before 15 November 2022. Studies focusing on the correlation between selenium and BMD, OP, or fracture were included. Effect sizes included regression coefficient (β), weighted mean difference (WMD), and odds ratio (OR). According to heterogeneity, the fixed-effect or random-effect model was used to assess the association between selenium and bone health.

Results

From 748 non-duplicate publications, 19 studies were included. We found a significantly positive association between dietary selenium intake (β = 0.04, 95% confidence interval (CI) 0.00 to 0.07, p = 0.029) as well as serum selenium (β = 0.13, 95% CI 0.00 to 0.26, p = 0.046) and BMD. Consistently, those with higher selenium intake had a lower risk of OP (OR = 0.47, 95% CI 0.31 to 0.72, p = 0.001), and patients with OP had a significantly lower level of serum selenium than healthy controls (WMD = -2.01, 95% CI -3.91 to -0.12, p = 0.037). High dietary selenium intake was associated with a lower risk of hip fracture (OR = 0.44, 95% CI 0.37 to 0.52, p < 0.001).

Conclusion

Selenium was positively associated with BMD and inversely associated with OP; dietary selenium intake was negatively associated with hip fracture. The causality and therapeutic effect of selenium on OP needs to be investigated in future studies.

Composite dietary antioxidant intake and osteoporosis likelihood in premenopausal and postmenopausal women: a population-based study in the United States

OBJECTIVE

Osteoporosis is a skeletal disease characterized by low bone mass, reduced bone strength, and increased fracture risk. We aimed to investigate the association between combined dietary antioxidant intake and the likelihood of osteoporosis in premenopausal and postmenopausal women, based on data from the National Health and Nutrition Examination Survey.

METHODS

Nutrient intake data were obtained using two 24-hour recalls. Composite dietary antioxidant index (CDAI), which refers to the intake amounts of β-carotene, vitamin A, vitamin C, vitamin E, selenium, zinc, copper, and iron, was then constructed. Prevalent osteoporosis was defined according to bone mineral density T scores of ≤ -2.5 and self-reports. Multiple logistic and Poisson regression models were used for association analyses.

RESULTS

A total of 3,418 participants (1,157 premenopausal and 2,261 postmenopausal women) 40 years or older were included, 776 (22.70%) of whom had prevalent osteoporosis. In terms of individual nutrients, postmenopausal women in the highest CDAI quartiles for dietary β-carotene, vitamin A, vitamin C, and iron intakes had a low likelihood of osteoporosis. Regarding the CDAI-osteoporosis association, postmenopausal women in the highest quartile were less likely to have osteoporosis (OR Q3 vs Q1 , 0.64; 95% CI, 0.43-0.96; OR Q4 vs Q1 , 0.56; 95% CI, 0.35-0.89; P for trend = 0.013), after controlling for covariates.

CONCLUSIONS

CDAI was negatively associated with the likelihood of osteoporosis in postmenopausal women. Our findings suggest that the combined intake of antioxidant nutrients can help reduce the likelihood of osteoporosis in women.

Relationship of blood heavy metals and osteoporosis among the middle-aged and elderly adults: A secondary analysis from NHANES 2013 to 2014 and 2017 to 2018

Objective

This study aimed to assess the relationship between blood heavy metals and a higher prevalence of osteoporosis in middle-aged and elderly US adults using the National Health and Nutritional Examination Surveys (NHANES).

Methods

The secondary data analysis was performed using the data of NHANES 2013–2014 and 2017–2018. We used the information, including physical examination, laboratory tests, questionnaires, and interviews, provided by participants in NHANES. Logistic regression and weighted quantile sum (WQS) regression models were used to explore the relationships between levels of blood heavy metals and a higher prevalence of osteoporosis.

Results

A total of 1,777 middle-aged and elderly participants were analyzed in this study, comprising 115 participants with osteoporosis and 1,662 without osteoporosis. Adjusted model 1 showed a significant positive relationship between cadmium (Cd) levels and a higher prevalence of osteoporosis (quartile 2, OR = 7.62; 95% CI, 2.01–29.03; p = 0.003; quartile 3, OR = 12.38; 95% CI, 3.88–39.60; p &lt; 0.001; and quartile 4, OR = 15.64; 95% CI, 3.22–76.08; p = 0.001). The fourth quartile of selenium (Se) level (OR = 0.34; 95% CI, 0.14–0.39; p &lt; 0.001) led to a lower prevalence of osteoporosis and exerted a protective effect on model 1. Other models produced similar results to those of model 1. A subgroup analysis showed that Cd levels were positively related to a higher prevalence of osteoporosis in all three models in women, while this relationship was not found in men. The fourth quartile of the Se level was related to a lower prevalence of osteoporosis in both male and female analyses. A significant positive relationship was found between the blood Cd level and a higher prevalence of osteoporosis in the non-smoking subgroup. Blood Se level showed a protective effect on the fourth quartile in both the smoking and non-smoking subgroups.

Conclusion

Blood Cd level aggravated the prevalence of osteoporosis, while blood Se level could be a protective factor in osteoporosis among the US middle-aged and older populations.

Genome-wide genotype-serum proteome mapping provides insights into the cross-ancestry differences in cardiometabolic disease susceptibility

Identification of protein quantitative trait loci (pQTL) helps understand the underlying mechanisms of diseases and discover promising targets for pharmacological intervention. For most important class of drug targets, genetic evidence needs to be generalizable to diverse populations. Given that the majority of the previous studies were conducted in European ancestry populations, little is known about the protein-associated genetic variants in East Asians. Based on data-independent acquisition mass spectrometry technique, we conduct genome-wide association analyses for 304 unique proteins in 2,958 Han Chinese participants. We identify 195 genetic variant-protein associations. Colocalization and Mendelian randomization analyses highlight 60 gene-protein-phenotype associations, 45 of which (75%) have not been prioritized in Europeans previously. Further cross-ancestry analyses uncover key proteins that contributed to the differences in the obesity-induced diabetes and coronary artery disease susceptibility. These findings provide novel druggable proteins as well as a unique resource for the trans-ancestry evaluation of protein-targeted drug discovery.

The effects of β-carotene on osteoporosis: a systematic review and meta-analysis of observational studies

PURPOSE

The aim is to evaluate the effect of β-carotene for osteoporosis and provide quantitative evidence.

METHOD

PubMed, Embase, Web of Science, and Cochrane Library were searched for eligible studies. Fifteen studies were included. Random-effect model was applied to pool the odds ratio (OR). The risk of osteoporosis and fracture were compared between low β-carotene intake group and high β-carotene intake group.

RESULT

The intake of β-carotene was unassociated with the overall risk of osteoporosis [OR = 0.733, 95% Cl (0.528, 1.018), p = 0.064]. Subgroup analysis showed that the intake of β-carotene was negatively associated with the risk of osteoporosis in both male subgroup [OR = 0.7, 95% Cl (0.549, 0.893), I² = 40.40%, p = 0.004] and female subgroup [OR = 0.684, 95% Cl (0.487, 0.960), I² = 86.40%, p = 0.028]. There was also a negative association between β-carotene intake and osteoporosis in Asia subgroup [OR = 0.512, 95% Cl (0.403, 0.650), I² = 0.00%, p = 0], whereas no association was observed in Western subgroup [OR = 1.107, 95% Cl (0.908, 1.350), I² = 2.30%, p = 0.314]. In addition, random-effect model was adopted to pool the standard mean difference (SMD), and the results showed that β-carotene intake was positively associated with overall bone mineral density (BMD) [SMD =  - 0.213, 95% Cl (- 0.391, - 0.034), I² = 87.30%, p = 0.019]. Subgroup analysis showed that β-carotene intake was positively associated with BMD in Asian participants [SMD =  - 0.394, 95% Cl (- 0.461, - 0.328), I² = 0, p = 0], while unassociated in Western participants [SMD =  - 0.047, 95% Cl (- 0.314, 0.219), I² = 78.9%, p = 0.727].

CONCLUSION

β-carotene may improve BMD and reduce the risk of osteoporosis and fracture. However, these effects could vary by gender and race and need to be further validated by longitudinal studies.

Vitamin A Nutritional Status Is a Key Determinant of Bone Mass in Children

The bone mass increases that occur during the period of childhood are of great significance for maximizing the peak bone mass in adults and preventing for osteoporosis. Studies have reported that VA can improve the bone health in adults. Moreover, limited studies have assessed such associations in children. In this cross-sectional study including 426 children, we assessed the children’s plasma retinol concentration by liquid chromatography–mass spectrometry and the dietary intake of VA and carotenoids using a structured Food Frequency Questionnaire. Their bone mineral content and bone mineral density (BMD) were measured using dual-energy X-ray absorptiometry. After adjusting for potential confounders, the restricted cubic spline revealed an inverted U-shaped association between plasma retinol concentration and BMD; the estimated effects on the TBLH BMD per μmol/L increase in the plasma retinol concentration were 1.79 × 10⁻² g/cm² below 1.24 μmol/L and −5.78 × 10⁻³ g/cm² above this point (p for non-linearity = 0.046). A multiple linear regression analysis revealed a positive association between the plasma retinol concentration and the TBLH BMC (β = 1.89, 95% CI: 1.64 × 10⁻¹–3.62, p = 0.032). In conclusion, an appropriate plasma retinol concentration and greater intakes of dietary VA and β-carotene may enhance the bone mineral status of children who are aged 6–9 years.

Superoxide Dismutase and Glutathione Reductase as Indicators of Oxidative Stress Levels May Relate to Geriatric Hip Fractures' Survival and Walking Ability: A Propensity Score Matching Study

Background

Oxidative stress status may affect bone metabolism and regeneration. However, few studies reported whether oxidative stress could impact the outcomes of hip fractures. This study aimed to explore if superoxide dismutase and glutathione reductase, the critical antioxidant enzymes, correlated with the prognosis of hip fractures.

Methods

Patients with hip fractures were extracted from our database, and those who met the inclusion criteria were analyzed. Propensity score matching was used to reduce the influence of confounding factors, and ROC curves based on matched populations were created to determine the optimal cutoff points of SOD and GR. Then, outcomes between SOD or GR and outcomes of hip fractures were compared.

Results

Out of 301 patients enrolled in this study, 50 patients died within one year. After a 1:1 PSM, the patients with less than 1-year survival had significantly lower SOD (p = 0.026) and GR (p = 0.021) than those who were still alive at one year. Logistics analysis showed that low SOD and low GR may be independent risk factors for 6-month survival, 1-year survival, 6-month free walking ability, and 1-year free walking ability.

Conclusion

SOD and GR may be the independent risk factors for survival and walking abilities of hip fractures.

Effect of Copper and Selenium Supplementation on the Level of Elements in Rats' Femurs under Neoplastic Conditions

A study was conducted to determine the effect of long-term supplementation with selenium and copper, administered at twice the level used in the standard diet of rats, on the content of selected elements in the femoral bones of healthy rats and rats with implanted LNCaP cancer cells. After an adaptation period, the animals were randomly divided into two experimental groups. The rats in the experimental group were implanted with prostate cancer cells. The rats in the control group were kept in the same conditions as those in the experimental group and fed the same diet, but without implanted cancer cells. The cancer cells (LNCaP) were intraperitoneally implanted in the amount of 1 × 106 (in PBS 0.4 mL) at the age of 90 days. The content of elements in the samples was determined by a quadrupole mass spectrometer with inductively coupled plasma ionization (ICP-MS). In the femoral bones of rats with implanted LNCaP cells, in the case of the standard diet and the copper-enriched diet, there was a marked decreasing trend in the content of the analysed elements relative to the control rats. This may indicate slow osteolysis taking place in the bone tissue. Contrasting results were obtained for the diet enriched with selenium; there was no significant reduction in the level of these elements, and there was even an increase in the concentrations of Fe and K in the bones of rats with implanted LNCaP cells. Particularly, numerous changes in the mineral composition of the bones were generated by enriching the diet with copper. The elements that most often underwent changes (losses) in the bones were cobalt, iron, manganese and molybdenum. The changes observed, most likely induced by the implantation of LNCaP cells, may indicate a disturbance of mineral homeostasis.

The Effects of Selenium on Bone Health: From Element to Therapeutics

Osteoporosis, characterized by low bone mass and a disruption of bone microarchitecture, is traditionally treated using drugs or lifestyle modifications. Recently, several preclinical and clinical studies have investigated the effects of selenium on bone health, although the results are controversial. Selenium, an important trace element, is required for selenoprotein synthesis and acts crucially for proper growth and skeletal development. However, the intake of an optimum amount of selenium is critical, as both selenium deficiency and toxicity are hazardous for health. In this review, we have systematically analyzed the existing literature in this field to determine whether dietary or serum selenium concentrations are associated with bone health. In addition, the mode of administration of selenium as a supplement for treating bone disease is important. We have also highlighted the importance of using green-synthesized selenium nanoparticles as therapeutics for bone disease. Novel nanobiotechnology will be a bridgehead for clinical applications of trace elements and natural products.

Higher Dietary Se Intake Is Associated With the Risk of New-Onset Fracture: A National Longitudinal Study for 20 Years

Background: The association between dietary selenium (Se) intake and osteoporosis-related fractures remains inconsistent. We aimed to examine the dose relationship between Se intake and incident fracture among Chinese adults. Methods: The dietary data were retrieved from the China Health and Nutrition Survey conducted between 1991 and 2011, and 17,150 participants aged above 20 were included. A 3-day, 24-h recall of food intake was performed to assess cumulative average dietary Se intake. The fracture was based on self-report in each survey between 1997 and 2011. The association between Se intake and fracture was tested by Cox regression, and the non-linear association was examined by restricted cubic splines (RCS). Results: There were 976 fracture cases during a mean of 10.2 years follow-up. In a fully adjusted Cox model, across the quartiles of Se intake, the hazard ratios (HRs) for fracture were 1.07 (95% CI .86-1.33), 1 (reference), 1.25 (95% CI 1.02-1.53), and 1.33 (95% CI 1.07-1.65). RCS showed a parabolic association (P non-linear = 0.037) between Se and fracture for men as well as a U-shape dose-response (P non-linear = 0.04) between Se and fracture for subjects living in highly urbanized areas. Conclusion: In conclusion, there is a non-linear association between selenium intake and fracture, with higher intake associated with increased risk. The shape of the association varies by gender and urbanization level.

Vitamin C in orthopedic practices: Current concepts, novel ideas, and future perspectives

Vitamin C (ascorbic acid), is an important antioxidant that has been applied broadly in the field of orthopaedics. Current research on vitamin C examines the molecule's role in bone and tendon physiology, as well as joint replacement and Postoperative pain. Most laboratory and human studies associate the use of vitamin C with improved bone health and tendon healing. Recent literature moderately supports the use of vitamin C to improve functional outcomes, decreased postoperative pain, and prevent complex regional pain syndrome following orthopaedic procedures. The perioperative use of vitamin C in patients undergoing joint replacement surgery and anterior cruciate ligament reconstruction is still under investigation. Overall, there is need for high-quality human trials to confirm whether vitamin C can potentiate the outcomes of orthopaedic procedures and to determine optimal dosage and means of administration to maximize its proposed benefits. The purpose of this review was to summarize the application of vitamin C in orthopaedic practices and to identify potential areas for future study.

Vitamin A and Bone Health: A Review on Current Evidence

Vitamin A is a fat-soluble micronutrient essential for growth, immunity, and good vision. The preformed retinol is commonly found in food of animal origin whereas provitamin A is derived from food of plant origin. This review summarises the current evidence from animal, human and cell-culture studies on the effects of vitamin A towards bone health. Animal studies showed that the negative effects of retinol on the skeleton were observed at higher concentrations, especially on the cortical bone. In humans, the direct relationship between vitamin A and poor bone health was more pronounced in individuals with obesity or vitamin D deficiency. Mechanistically, vitamin A differentially influenced the stages of osteogenesis by enhancing early osteoblastic differentiation and inhibiting bone mineralisation via retinoic acid receptor (RAR) signalling and modulation of osteocyte/osteoblast-related bone peptides. However, adequate vitamin A intake through food or supplements was shown to maintain healthy bones. Meanwhile, provitamin A (carotene and β-cryptoxanthin) may also protect bone. In vitro evidence showed that carotene and β-cryptoxanthin may serve as precursors for retinoids, specifically all-trans-retinoic acid, which serve as ligand for RARs to promote osteogenesis and suppressed nuclear factor-kappa B activation to inhibit the differentiation and maturation of osteoclasts. In conclusion, we suggest that both vitamin A and provitamin A may be potential bone-protecting agents, and more studies are warranted to support this hypothesis.

Multivitamins and risk of fragility hip fracture: a systematic review and meta-analysis

PURPOSE

Hip fracture is a severe complication of osteoporosis and is associated with a significant healthcare burden worldwide. This meta-analysis explores the association between combined multivitamin use and hip fracture risk. Our results provide more patient-centered insight into the impact of supplement use on osteoporosis outcomes.

METHODS

We searched three online databases in August 2019 and included studies that reported on multivitamin use in patients with osteoporotic hip fractures. The inclusion criteria were (1) adult patients with osteoporotic hip fractures, (2) availability of full-text articles in English, and (3) at least 1 year of follow-up. No suitable randomized controlled trials could be identified for inclusion in the analysis. The quality of the included studies was assessed using the Newcastle-Ottawa Scale (NOS).

RESULTS

Eight studies containing 80,148 subjects in total were included in this study. Among these, 4237 cases of fragility hip fracture were reported. The average age was 69±5.3 years, and 21% of subjects were male. Multivitamin use was found to be significantly associated with a lower risk of sustaining a fragility hip fracture (OR 0.49, 95%CI: 0.32-0.77). The Begg and Mazumdar test and funnel plot indicated that no significant publication bias was present.

CONCLUSION

Combined multivitamins are amongst the most widely used supplements and are often preferred over single vitamins. Our meta-analysis indicates that multivitamin use is significantly protective against osteoporotic hip fracture. In the future, randomized controlled trials should be performed to establish multivitamins as effective preventative measures for this injury.

Nutritional Supplements and Skeletal Health

PURPOSE OF REVIEW

Nutrition influences skeletal health throughout the lifespan, from the impact of maternal intakes during development, through the development of peak bone mass, to the rate of bone loss during aging. However, there are limited data available on the effects of nutritional supplements on bone density, let alone fracture risk. This review will assess the current literature, focusing on human studies, and emphasizing nutrients where bone density or fracture data are available.

RECENT FINDINGS

Calcium and vitamin D supplements, in combination, reduce fracture risk, particularly in populations with low intakes. Extensive recent analyses have supported the safety of these interventions at recommended intakes. There is growing evidence that specific isoflavones may improve bone density although fracture data are lacking. Multiple other nutrient supplements may benefit skeletal health, but data are limited. The effect size of nutrient interventions are relatively small, requiring large sample sizes for trials with bone outcomes, may be difficult to blind, and the impact of supplementation may depend on baseline intake. However, nutrition is the only intervention that can be implemented life long and on a population wide basis. Further investigation is needed into the potential benefits of nutritional supplements to determine in which settings supplements may add benefit in addition to dietary intakes.

Is Zinc an Important Trace Element on Bone-Related Diseases and Complications? A Meta-analysis and Systematic Review from Serum Level, Dietary Intake, and Supplementation Aspects

Bone-related diseases are very common problems, especially in the elderly population. Zinc takes part in the growth and maintenance of healthy bones. This meta-analysis aims to evaluate the effects of zinc supplementation or dietary zinc intake on serum zinc levels and bone turnover markers. A systematical research was performed with 2899 articles in PubMed, WoS, and Scopus for relevant articles in English which have mean/standard deviation values of serum zinc levels, dietary zinc intake/zinc supplementation (mg/day), and bone turnover markers up to February 2020. In the overall analysis, serum zinc level was significantly lower in patients with osteoporosis compared with controls (p 0.0002). Dietary zinc intake decreased in the fracture group compared with controls according to subgroup analysis patients with fracture (p 0.02). Zinc supplementation was effective on the femoral neck (p < 0.0001) and lumbar spine (p 0.05) bone mineral density (BMD). In the correlation analysis of the data obtained from all of the included studies, serum osteocalcin (p 0.0106, r - 0.9148) correlated with serum zinc level. In conclusion, serum zinc level and dietary zinc intake could have an essential role in preventing osteoporosis. Zinc supplementation might improve bone turnover markers for bone formation such as serum osteocalcin and serum alkaline phosphatase and also, BMD at the site of the femoral neck.

Selenium status is independently related to bone mineral density, FRAX score, and bone fracture history: NHANES, 2013 to 2014

Selenium is an essential trace mineral element for humans. Although previous in vitro and animal studies have reported the vital role of selenium in bone, the results of the relationship between the selenium status and bone health were inconsistent in epidemiological studies. The risk of selenium deficiency is negligible for U.S. general population, however, the relationship between selenium status and bone health has never been surveyed in a nationally representative sample. In this study, we analyzed the data of 2983 adults (aged ≥40 years) in the National Health and Nutrition Examination Survey (NHANES) 2013-2014 to investigate the association among three markers of the selenium status (measured from whole blood, serum, and dietary intake), total spine and femur bone mineral density (BMD), and FRAX scores, and history of bone fractures. We found a one-unit increase in the ln-whole-blood selenium level was correlated with an increase in the total femur BMD of 0.064 g/cm² (S.E. = 0.025; P = 0.022) in all participants and 0.086 g/cm² (S.E. = 0.031; P = 0.013) in menopausal women. Additionally, a one-unit increase in the ln-selenium intake amount was associated with an increase in the total femur BMD of 0.014 g/cm² (S.E. = 0.007; P = 0.043) in all participants. We also found that the dietary and whole-blood selenium statuses were negatively associated with the FRAX score, while levels of all the three selenium biomarkers were negatively associated with a history of bone fractures. In conclusion, increased selenium status is correlated with an increased total femur BMD, decreased FRAX scores, and a reduced incidence of previous bone fractures in the U.S. representative survey of adults. Further study is warranted to clarify the causal inference.

Arsenic, cadmium, and selenium exposures and bone mineral density-related endpoints: The HORTEGA study

BACKGROUND AND OBJECTIVES

Experimental data suggest that trace elements, such as arsenic (As), cadmium (Cd), and selenium (Se) can influence the bone remodeling process. We evaluated the cross-sectional association between As, Cd, and Se biomarkers with bone mineral density (BMD) measured at the calcaneus, in a representative sample of a general population from Spain. As secondary analyses we evaluated the associations of interest in subgroups defined by well-established BMD determinants, and also conducted prospective analysis of osteoporosis-related incident bone fractures restricted to participants older than 50 years-old.

METHODS

In N = 1365 Hortega Study participants >20 years-old, urine As and Cd were measured by inductively coupled-plasma mass spectrometry (ICPMS); plasma Se was measured by atomic absorption spectrometry (AAS) with graphite furnace; and BMD at the calcaneus was measured using the Peripheral Instaneuous X-ray Imaging system (PIXI). As levels were corrected for arsenobetaine (Asb) to account for inorganic As exposure.

RESULTS

The median of total urine As, Asb-corrected urine As, urine Cd, and plasma Se was 61.3, 6.53 and 0.39 μg/g creatinine, and 84.9 μg/L, respectively. In cross-sectional analysis, urine As and Cd were not associated with reduced BMD (T-score < -1 SD). We observed a non-linear dose-response of Se and reduced BMD, showing an inverse association below ~105 μg/L, which became increasingly positive above ~105 μg/L. The evaluated subgroups did not show differential associations. In prospective analysis, while we also observed a U-shape dose-response of Se with the incidence of osteoporosis-related bone fractures, the positive association above ~105 μg/L was markedly stronger, compared to the cross-sectional analysis.

CONCLUSIONS

Our results support that Se, but not As and Cd, was associated to BMD-related disease. The association of Se and BMD-related disease was non-linear, including a strong positive association with osteoporosis-related bone fractures risk at the higher Se exposure range. Considering the substantial burden of bone loss in elderly populations, additional large prospective studies are needed to confirm the relevance of our findings to bone loss prevention in the population depending on Se exposure levels.

Effects of β-carotene intake on the risk of fracture: a Bayesian meta-analysis

BACKGROUND

Epidemiological studies examining the association between β-carotene intake and risk of fracture have reported inconsistent findings. We conducted a meta-analysis to investigate the association between β-carotene intake and risk of fracture.

METHODS

We systematically searched PubMed, EMBASE and Cochrane library databases for relevant articles that were published until December 2019. We also identified studies from reference lists of articles identified from the clinical databases. The frequentist and Bayesian random-effects model was used to synthesize data.

RESULTS

Nine studies with a total of 190,545 men and women, with an average age of 59.8 years, were included in this meta-analysis. For β-carotene intake (1.76-14.30 mg/day), the pooled risk ratio (RR) of any fracture was 0.67 (95% Credible Interval (CrI): 0.51-0.82; heterogeneity: P = 0.66, I2 = 0.00%) and 0.63 (95%CrI: 0.44-0. 82) for hip fracture. By study design, the pooled RRs were 0.55 (95% CrI: 0.14-0.96) for case-control studies and 0.82 (95% CrI: 0.58-0.99) for cohort studies. By geographic region, the pooled RRs were 0.58 (95% CrI: 0.28-0.89), 0.86 (95% CrI: 0.35-0.1.37), and 0.91(95% CrI: 0.75-1.00) for studies conducted in China, the United States, and Europe, respectively. By sex, the pooled RRs were 0.88 (95% CrI: 0.73-0.99) for males and 0.76 (95% CrI, 0.44-1.07) for females. There was a 95% probability that β-carotene intake reduces risk of hip fracture and any type of fracture by more than 20%.

CONCLUSIONS

The present meta-analysis suggests that β-carotene intake was inversely associated with fracture risk, which was consistently observed for case-control and cohort studies. Randomized controlled trials are warranted to confirm this relationship.

Selenium and bone health: a protocol for a systematic review and meta-analysis

INTRODUCTION

Bone health affects the ability of human body to stay active, and its degradation can cause considerable morbidity and mortality. The factors related to bone health play an important role in preventing osteoporosis and its adverse consequences. However, the risk factors for osteoporosis have not been fully elucidated. Deficiency in the trace element selenium may be one of the risk factors for the development of osteoporosis. Previous studies have investigated the effects of selenium on osteoporosis; however, the results are inconclusive. Therefore, the present study aimed to systematically examine the existing literature on the associations between dietary or serum selenium and bone mineral density (BMD), osteoporosis or osteoporotic fractures, and to quantify such associations through meta-analysis.

METHODS AND ANALYSIS

PubMed, Embase and Cochrane Library will be searched using a specified search strategy to identify relevant studies up to October 2019. Both interventional and observational studies in humans will be included. The outcomes will include BMD and the prevalence or incidence of osteoporosis and osteoporotic fractures. For dietary or serum selenium and BMD, osteoporosis or osteoporotic fractures pooled analyses, estimates will be expressed as the mean difference, and the pooled OR, relative risk, HR or beta coefficient, and corresponding 95% CIs. Heterogeneity of the studies and publication bias will be investigated accordingly. To assess the quality and the risk of bias of the included studies, the Newcastle-Ottawa Quality Scale or the Cochrane risk of bias assessment tool will be used where appropriate.

ETHICS AND DISSEMINATION

Since no private and confidential patient data will be included in the reporting, approval from an ethics committee is not required. The results will be published in a peer-reviewed journal. The study raises no ethical issues.

PROSPERO REGISTRATION NUMBER

CRD42019147188.

The interplay between host genetics and the gut microbiome reveals common and distinct microbiome features for complex human diseases

BACKGROUND

Interest in the interplay between host genetics and the gut microbiome in complex human diseases is increasing, with prior evidence mainly being derived from animal models. In addition, the shared and distinct microbiome features among complex human diseases remain largely unclear.

RESULTS

This analysis was based on a Chinese population with 1475 participants. We estimated the SNP-based heritability, which suggested that Desulfovibrionaceae and Odoribacter had significant heritability estimates (0.456 and 0.476, respectively). We performed a microbiome genome-wide association study to identify host genetic variants associated with the gut microbiome. We then conducted bidirectional Mendelian randomization analyses to examine the potential causal associations between the gut microbiome and complex human diseases. We found that Saccharibacteria could potentially decrease the concentration of serum creatinine and increase the estimated glomerular filtration rate. On the other hand, atrial fibrillation, chronic kidney disease and prostate cancer, as predicted by host genetics, had potential causal effects on the abundance of some specific gut microbiota. For example, atrial fibrillation increased the abundance of Burkholderiales and Alcaligenaceae and decreased the abundance of Lachnobacterium, Bacteroides coprophilus, Barnesiellaceae, an undefined genus in the family Veillonellaceae and Mitsuokella. Further disease-microbiome feature analysis suggested that systemic lupus erythematosus and chronic myeloid leukaemia shared common gut microbiome features.

CONCLUSIONS

These results suggest that different complex human diseases share common and distinct gut microbiome features, which may help reshape our understanding of disease aetiology in humans. Video Abstract.

Role of Vitamin C in Osteoporosis Development and Treatment-A Literature Review

Osteoporosis and associated low energy fractures are a significant clinical problem, especially in the elderly population. The occurrence of a hip fracture is associated with significant mortality and a high risk of disability. For this, apart from the treatment of osteoporosis, effective prevention of both the development of the disease and related fractures is extremely important. One aspect of osteoporosis prevention is proper dietary calcium intake and normal vitamin D3 levels. However, there is some evidence for a potential role of vitamin C in osteoporosis and fracture prevention, too. This review aims to summarize the current knowledge about the role of vitamin C in osteoporosis development, prevention and treatment. The PubMed/Medline search on the role of vitamin C in bone metabolism database was performed for articles between 2000 and May 2020. Reports from in vitro and animal studies seem promising. Epidemiological studies also indicate the positive effect of high vitamin C content in the daily diet on bone mineral density. Despite promising observations, there are still few observational and intervention studies and their results do not allow for unequivocal determination of the benefits of high daily intake of vitamin C or its long-term supplementation.

Association between dietary selenium intake and the prevalence of osteoporosis: a cross-sectional study

Objective

To examine the correlation between dietary selenium (Se) intake and the prevalence of osteoporosis (OP) in the general middle-aged and older population in China.

Methods

Data for analyses were collected from a population based cross-sectional study performed at the Xiangya Hospital Health Management Centre. Dietary Se intake was evaluated using a validated semi-quantitative food frequency questionnaire. OP was diagnosed on the basis of bone mineral density scans using a compact radiographic absorptiometry system. The correlation between dietary Se intake and the prevalence of OP was primarily examined by multivariable logistic regression.

Results

This cross-sectional study included a total of 6267 subjects (mean age: 52.2 ± 7.4 years; 42% women), and the prevalence of OP among the included subjects was 9.6% (2.3% in men and 19.7% in women). Compared with the lowest quartile, the energy intake, age, gender and body mass index (BMI)-adjusted odds ratios of OP were 0.72 (95% confidence interval [CI] 0.55–0.94), 0.72 (95% CI 0.51–1.01) and 0.47 (95% CI 0.31–0.73) for the second, third and fourth quartiles of dietary Se intake, respectively (P for trend = 0.001). The results remained consistent in male and female subjects. Adjustment for additional potential confounders (i.e., smoking status, drinking status, physical activity level, nutritional supplements, diabetes, hypertension, fibre intake, and calcium intake) did not cause substantial changes to the results.

Conclusions

In the middle-aged and older humans, participants with lower levels of dietary Se intake have a higher prevalence of OP in a dose-response manner.

Vitamin C intake in relation to bone mineral density and risk of hip fracture and osteoporosis: a systematic review and meta-analysis of observational studies

We aimed to systematically review available data on the association between vitamin C intake and bone mineral density (BMD), as well as risk of fractures and osteoporosis, and to summarise this information through a meta-analysis. Previous studies on vitamin C intake in relation to BMD and risk of fracture and osteoporosis were selected through searching PubMed, Scopus, ISI Web of Science and Google Scholar databases before February 2017, using MeSH and text words. To pool data, either a fixed-effects model or a random-effects model was used, and for assessing heterogeneity, Cochran's Q and I 2 tests were used. Subgroup analysis was applied to define possible sources of heterogeneity. Greater dietary vitamin C intake was positively associated with BMD at femoral neck (pooled r 0·18; 0·06, 0·30) and lumbar spine (pooled r 0·14; 95 % CI 0·06, 0·22); however, significant between-study heterogeneity was found at femoral neck: I 2=87·6 %, P heterogeneity<0·001. In addition, we found a non-significant association between dietary vitamin C intake and the risk of hip fracture (overall relative risk=0·74; 95 % CI 0·51, 1·08). Significant between-study heterogeneity was found (I 2=79·1 %, P heterogeneity<0·001), and subgroup analysis indicated that study design, sex and age were the main sources of heterogeneity. Greater dietary vitamin C intake was associated with a 33 % lower risk of osteoporosis (overall relative risk=0·67; 95 % CI 0·47, 0·94). Greater dietary vitamin C intake was associated with a lower risk of hip fracture and osteoporosis, as well as higher BMD, at femoral neck and lumbar spine.

Can Dietary Intake of Vitamin C-Oriented Foods Reduce the Risk of Osteoporosis, Fracture, and BMD Loss? Systematic Review With Meta-Analyses of Recent Studies

Background: Several epidemiological studies have been performed to evaluate the association of dietary intake of vitamin C-oriented foods (DIVCF) with risk of fracture and bone mineral density (BMD) loss, but the results remain controversial. Therefore, we conducted a systematic meta-analysis to assess this correlation. Methods: We searched EmBase, PubMed, Web of Science, and the Chinese database CNKI for relevant articles published up to August 2019. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated using the random- or fixed-effects model. Discrepancies were resolved by consultation with a third expert. Results: A total of 13 eligible articles (including 17 studies) with 19,484 subjects were identified for the present meta-analysis. The pooled RR of hip fracture for the highest vs. lowest category was 0.66 (95% CI, 0.47-0.94) for DIVCF, i.e., people with a greater frequency of Vitamin C uptake had a 34% (95% CI, 6%-53%) lower prevalence of hip fracture. In subgroup analyses stratified by study design, gender, and age, the negative associations were statistically significant. Furthermore, the statistical analysis of the association between DIVCF and risk of osteoporosis (RR, 0.66; 95% CI, 0.48-0.92), BMD at the lumbar spine (pooled r, 0.15; 95% CI, 0.09-0.23), and BMD at the femoral neck (pooled r, 0.20; 95% CI, 0.11-0.34) showed beneficial effects of DIVCF. Conclusion: Our meta-analysis indicates that DIVCF is negatively associated with the risk of hip fracture, osteoporosis, and BMD loss, suggesting that DIVCF decreases the risk of hip fracture, osteoporosis, and BMD loss.

Higher dietary carotenoid intake associated with lower risk of hip fracture in middle-aged and elderly Chinese: A matched case-control study

BACKGROUND

Mechanism studies have suggested that carotenoids may benefit bone health due to their antioxidant properties, but epidemiological data on their effects on risk of hip fracture are sparse.

PURPOSE

To explore the relationships between dietary total and specific carotenoids and the risk of hip fracture in a middle-aged and elderly Chinese population.

DESIGN

A case-control study of 1070 patients with hip fractures (diagnosed within 2 weeks) aged 55-80 years and 1070 age- (within 3 years) and gender-matched controls was conducted in Guangdong, China between 2009 and 2015. Information on dietary carotenoid intake was assessed using a 79-item food frequency questionnaire administered in face-to-face interviews, and general information was collected using structured questionnaires. The univariate and multivariate conditional logistic regression models were applied to analyze the associations.

MAIN RESULTS

Higher intakes of both total and some specific carotenoids (including β-carotene, β-cryptoxanthin and lutein/zeaxanthin) were significantly associated with a lower risk of hip fracture (all p trends <0.01). Compared with the lowest quartile of carotenoids, the multivariate-adjusted odds ratios and 95% confidential intervals of the highest quartile were 0.44 (0.29, 0.68) (total carotenoids), 0.50 (0.29, 0.69) (β-carotene), 0.55 (0.38, 0.80) (β-cryptoxanthin) and 0.40 (0.27, 0.59) (lutein/zeaxanthin), respectively. There were no statistically significant associations between α-carotene and lycopene intakes and hip fracture risk after adjustment for various confounding variables.

CONCLUSION

These results suggest that the consumption of carotenoids may be protective against hip fracture in middle-aged and elderly Chinese adults.

Carotenoids and risk of fracture: a meta-analysis of observational studies

To quantify the association between dietary and circulating carotenoids and fracture risk, a meta-analysis was conducted by searching MEDLINE and EMBASE databases for eligible articles published before May 2016. Five prospective and 2 case-control studies with 140,265 participants and 4,324 cases were identified in our meta-analysis. Among which 5 studies assessed the association between dietary carotenoids levels and hip fracture risk, 2 studies focused on the association between circulating carotenoids levels and any fracture risk. A random-effects model was employed to summarize the risk estimations and their 95% confidence intervals (CIs). Hip fracture risk among participants with high dietary total carotenoids intake was 28% lower than that in participants with low dietary total carotenoids (OR: 0.72; 95% CI: 0.51, 1.01). A similar risk of hip fracture was found for β-carotene based on 5 studies, the summarized OR for high vs. low dietary β-carotene was 0.72 (95% CI: 0.54, 0.95). However, a significant between-study heterogeneity was found (total carotene: I2 = 59.4%, P = 0.06; β-carotene: I2 = 74.4%, P = 0.04). Other individual carotenoids did not show significant associations with hip fracture risk. Circulating carotene levels had no significant association with any fracture risk, the pooled OR (95% CI) was 0.83 (0.59, 1.17). Based on the evidence from observational studies, our meta-analysis supported the hypothesis that higher dietary total carotenoids or β-carotene intake might be potentially associated with a low risk of hip fracture, however, future well-designed prospective cohort studies and randomized controlled trials are warranted to specify the associations between carotenoids and fracture.

Dietary vitamin C intake and the risk of hip fracture: a dose-response meta-analysis

The meta-analysis suggested that dietary vitamin C was statistically inversely associated with the risk of hip fracture (overall OR = 0.73, 95% CI = 0.55-0.97, I ² = 69.1%) and with the increase of 50 mg/day vitamin C intake, the risk of hip fracture will reduce by 5% (OR = 0.95, 95% CI 0.91-1.00, P = 0.05).

INTRODUCTION

Previous studies had inconsistent findings regarding the association between vitamin C intake and the risk of hip fracture. Therefore, we conducted a meta-analysis to evaluate the association of dietary vitamin C intake and the risk of hip fracture.

METHODS

Relevant studies were identified by searching PubMed, Embase, and Web of Science up to December 2016. Additional articles were identified from reviewing the reference lists of relevant articles. The summary relative risks (RRs) or odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by random effects model. Funnel plot and Egger's test were used to test publication bias.

RESULTS

The total six articles containing 7908 controls and 2899 cases of hip fracture were included in this meta-analysis. By comparing the highest versus the lowest categories of vitamin C intake, we found that dietary vitamin C was statistically correlated with the risk of hip fracture [overall OR = 0.73, 95% CI = 0.55-0.97, I ² = 69.1%]. A linear dose-response association showed that the increase with vitamin C intake of 50 mg/day statistically reduced by 5% (OR = 0.95, 95% CI 0.91-1.00, P = 0.05) the risk of hip fracture.

CONCLUSIONS

In conclusion, the results of current meta-analysis strongly support that increasing dietary vitamin C intake can decrease the risk of hip fracture. In order to verify the association of vitamin C intake and hip fracture risk, further well-designed largely randomized controlled trials (RCTs) are needed.

Prospective study of dietary Non Enzymatic Antioxidant Capacity on the risk of hip fracture in the elderly

BACKGROUND

Dietary antioxidants may play an important role in the prevention of bone loss and associated fractures by reducing levels of oxidative stress. We prospectively investigated the association between dietary Non Enzymatic Antioxidant Capacity (NEAC) and the risk of hip fracture and whether this effect was modified by smoking.

METHOD

In the Swedish National March Cohort 13,409 men and women over the age of 55 who had not experienced cancer, cardiovascular disease or hip fracture, were followed through record-linkages from 1997 through 2010. NEAC was assessed by a validated food frequency questionnaire collected at baseline. We categorized the distribution of NEAC into sex-specific quartiles and used multivariable adjusted Cox proportional hazards regression models to estimate hazard ratios (HRs) with 95% confidence intervals (95% CI).

RESULTS

During a mean follow-up time of 12.4years, we identified 491 incident cases of first hip fracture. Subjects in the highest quartile of dietary NEAC had a 39% lower risk of incident hip fracture compared to those in the lowest quartile (HR: 0.61; 95% CI: 0.44-0.85). The association was non-linear (p for non-linearity: 0.004) with a potential threshold between the first and the second quartile and no further risk reduction at higher levels of dietary NEAC. Due to a low smoking prevalence in our study population, we had limited power to detect effect modification between dietary NEAC and smoking on a multiplicative or additive scale.

CONCLUSION

Higher dietary NEAC intake is associated with lower risk of hip fracture in the elderly.

Association of dietary and serum vitamin E with bone mineral density in middle-aged and elderly Chinese adults: a cross-sectional study

Previous studies have suggested that vitamin E (VE) may affect bone health, but the findings have been inconclusive. We examined the relationship between VE status (in both diet and serum) and bone mineral density (BMD) among Chinese adults. This community-based study included 3203 adults (2178 women and 1025 men) aged 40-75 years from Guangzhou, People's Republic of China. General and dietary intake information were collected using structured questionnaire interviews. The serum α-tocopherol (TF) level was quantified by reversed-phase HPLC. The BMD of the whole body, the lumbar spine and left hip sites (total, neck, trochanter, intertrochanter and Ward's triangle) were measured using dual-energy X-ray absorptiometry. In women, the dietary intake of VE was significantly and positively associated with BMD at the lumbar spine, total hip, intertrochanter and femur neck sites after adjusting for covariates (P(trend): 0·001-0·017). Women in quartile 3 of VE intake typically had the highest BMD; the covariate-adjusted mean BMD were 2·5, 3·06, 3·41 and 3·54% higher, respectively, in quartile 3 (v. 1) at the four above-mentioned sites. Similar positive associations were observed between cholesterol-adjusted serum α-TF levels and BMD at each of the studied bone sites (P(trend): 0·001-0·022). The covariate-adjusted mean BMD were 1·24-4·83% greater in quartile 4 (v. 1) in women. However, no significant associations were seen between the VE levels (dietary or serum) and the BMD at any site in men. In conclusion, greater consumption and higher serum levels of VE are associated with greater BMD in Chinese women but not in Chinese men.