Vitamin C supplement use and bone mineral density in postmenopausal women

Sex-specific association between dietary carbohydrate intake and bone mineral density among American adolescents: National Health and Nutrition Examination Survey

BACKGROUND

The association between dietary carbohydrate intake and bone mineral density (BMD) remains controversial, and research on this topic among adolescents is lacking. This study aimed to examine the relationship between dietary carbohydrate intake and BMD in adolescents.

METHODS

This study examined data from adolescents (12-19 years) in the National Health and Nutrition Examination Survey (NHANES) (2005-2010). Dietary carbohydrate intake was assessed via two 24-hour recalls. BMD at the lumbar spine, total spine, total femur, and femoral neck was measured by dual-energy X-ray absorptiometry (DXA). A two-day dietary weighted multivariate regression analysis was employed to adjusted for covariates and assess the relationship between carbohydrate intake and BMD. The consistency of the associations and potential modifying factors were further evaluated through stratification and interaction analyses, both weighted by the two-day dietary data. Additionally, stratified curve fitting elucidated sex-specific differences in this relationship.

RESULTS

After excluding missing data, 2616 adolescents aged 12-19 years were included in the study. In the fully adjusted two-day dietary sample weighted analysis model, a positive association was observed between dietary carbohydrate intake and BMD among all participants. Dietary carbohydrate intake was positively associated with lumbar spine BMD (β = 1.31, 95 % CI = 0.38-2.23), total spine BMD (β = 1.31, 95 % CI = 0.39-2.24), and femoral neck BMD (β = 0.91, 95 % CI = 0.05-1.77) among all participants. Subgroup analyses revealed a significant sex interaction effect (P < 0.05). Subsequently, stratified curve fitting and sex-specific multivariate regression analyses were conducted. The results indicated a positive correlation between dietary carbohydrate intake and BMD in males, whereas no such correlation was observed in females. The multivariate analysis results further confirmed the sex-specific differences in the relationship between dietary carbohydrate intake and BMD, consistent with the initial findings.

CONCLUSION

Our study demonstrated that carbohydrate consumption significantly enhances BMD during adolescent bone growth. This effect is sex-specific.

Serum vitamin C levels and risk of osteoporosis: results from a cross-sectional study and Mendelian randomization analysis

BACKGROUND

The role of vitamin C as an antioxidant in guarding against osteoporosis in adults is still debated. This research employs both a cross-sectional study and a two-sample bidirectional Mendelian randomization (MR) analysis to explore how serum vitamin C levels correlate with the incidence of osteoporosis among adults.

METHODS

In this study, we utilized data from the National Health and Nutrition Examination Survey (NHANES) database for the years 2003-2006, and 2017-2018 to conduct both a cross-sectional analysis and MR to investigate the relationship between serum vitamin C levels and the risk of osteoporosis in adults. We adjusted our analyses for essential demographic and lifestyle variables, and applied logistic regression techniques. Genetic determinants of vitamin C levels were analyzed through MR, using methods like inverse-variance weighted (IVW) and MR-Egger to assess causality. Statistical computations were carried out in R, incorporating visual tools such as restricted cubic spline curves (RCS) and forest plots to clarify the dose-response dynamics and variations across different subgroups. This study was approved by the NCHS Ethics Review Board, and informed consent was obtained from all participants.

RESULTS

In our investigation, we analyzed data from 3,940 participants, among whom 291 were diagnosed with osteoporosis. The logistic regression analysis of serum vitamin C quartiles did not indicate a significant trend. The most adjusted model showed a slight, albeit inconsistent, protective effect in the highest quartile (OR = 0.68, 95% CI: 0.47-0.99, P = 0.22). Mendelian randomization, employing methods such as IVW, reinforced the absence of a significant causal relationship between serum vitamin C levels and osteoporosis risk (IVW OR = 1.000, 95% CI: 0.999-1.001, P = 0.601).Subgroup analyses, visualized through forest plots and restricted cubic spline (RCS) curves, supported the primary findings, showing no significant effects or interactions between vitamin C levels and osteoporosis risk across different demographic and lifestyle subgroups. The RCS analysis particularly highlighted a lack of significant non-linear relationships between serum vitamin C concentration and the odds of osteoporosis (P for nonlinear = 0.840).

CONCLUSIONS

The cross-sectional study revealed that higher serum vitamin C levels do not consistently correlate with a reduced risk of osteoporosis. Meanwhile, the Mendelian randomization analysis confirmed that there is no genetic evidence to suggest a causal relationship between vitamin C levels and osteoporosis risk. Recent research highlights the polygenic nature of osteoporosis, with genetic predispositions playing a significant role in disease risk. The relationship between serum vitamin C and osteoporosis requires further research. This suggests the need for further investigation into the connection between vitamin C and bone health.

Diversity of the diet is correlated with osteoporosis in post-menopausal women: an Iranian case-control study

Background

Proper nutrition is a crucial factor in preventing osteoporosis, a significant pathological cause linked to skeletal weakness; this study investigated the relationship between dietary diversity score and food group diversity score with osteoporosis in postmenopausal women.

Methods

This case-control study was conducted on 378 menopausal women aged 45-85 in Tehran, Iran. The age-matching method to control the confounding effect of age was used. The method of dual-energy X-ray absorptiometry (DXA) was used for assessing the bone mineral density of lumbar vertebrae and femoral neck. The bone mass status was evaluated with WHO criteria. All subjects were divided into the osteoporosis group and the non-osteoporosis group according to their T-score. A convenience sampling method was utilized to select the participants, which included two groups: case (n = 189) and control (n = 189). Data was collected using demographic and anthropometric information questionnaires, a valid 147 item food frequency questionnaire, and a physical activity questionnaire. Statistical analyses were conducted using SPSS-26, and p-values less than 0.05 were deemed to be statistically significant.

Results

The results indicated significant differences in weight, body mass index, physical activity, smoking, and alcohol use between the two groups. The mean ± standard deviation of dietary diversity score (DDS) was lower in participants with osteoporosis (case) (3.31 ± 1.26) than in control (4.64 ± 1.33) (p < 0.001). The mean ± standard deviation of diversity score of cereals, fruits, and vegetables in the osteoporosis group (respectively: 0.71 ± 0.21, 0.94 ± 0.76, and 0.45 ± 0.44) was less than the control group (respectively: 0.80 ± 0.21, 1.64 ± 0.55 and 0.87 ± 0.42) (p < 0.001). After adjusting the confounding variables, the risk of osteoporosis had an inverse relationship with the diversity score of vegetable (OR = 0.16; 95%CI: 0.07-0.35), bread and cereal (OR = 0.21; 95% CI: 0.05-0.87) and fruit (OR = 0.35; 95%CI: 0.22-0.56) (p < 0.05). Nevertheless, no discernible correlation was seen between the tertiles of DDS, dairy and meat diversity score, and osteoporosis.

Conclusion

We found a correlation between the diversity score of fruits, vegetables, and grains and osteoporosis. However, there is no significant correlation between the DDS triads and the diversity score of dairy products and meats with osteoporosis.

The association of combined vitamin C and D deficiency with bone mineral density and vertebral fracture

PURPOSE

Both vitamin C and D deficiencies are extremely common in clinical practice, especially in elderly population. Unfortunately, the role of vitamin C deficiency in osteoporosis related consequences is often neglected. The aim of the present study is to analyse if combined vitamin C and D deficiency would have an association with bone mineral density (BMD) and osteoporotic vertebral fracture (OVF).

METHODS

Ninety-nine post-menopausal female patients admitted in the department of spine surgery of third affiliated hospital of Sun Yat-sen University were enrolled in the study. The participants were divided into four groups; vitamin D deficiency alone (comparator group), vitamin C deficiency alone and combined vitamin C and D deficiency as experimental group. The levels of vitamin C, vitamin D, calcium, phosphorous, BMD and condition of OVF were analysed.

RESULTS

There were statistically significant differences between the groups in terms of vitamin C and D levels. In terms of lumbar BMD, significant differences were observed between vitamin D deficiency alone and combined vitamin C and D deficiency. Only the combined vitamin C and D deficiency had a significant negative association with lumbar BMD and T-score. Similarly, combined vitamin C and D deficiency had a significant positive association with lumbar osteoporosis. None of the groups had any significant association with OVF. Combined vitamin C and D deficiency was found to be significantly associated with lower lumbar BMD and osteoporosis.

CONCLUSION

Combined vitamin C and D deficiency results in lower bone mineral density and higher risk of osteoporosis. We believe that existence of deficiencies of both vitamins could have a synergistic effect. Therefore, we recommend that vitamin C and D should be routinely measured in clinical practice.

Association between composite dietary antioxidant and bone mineral density in children and adolescents aged 8-19 years: findings from NHANES

Dietary antioxidants may have beneficial effects on bone health, but it remains uncertain in children and adolescents. This study investigates the association of composite dietary antioxidant index (CDAI) with bone mineral density (BMD) in children and adolescents aged 8-19 years from the National Health and Nutrition Examination Survey (NHANES) 2007-2010. The study assessed the relationship between CDAI and BMD in 2994 individuals aged 8-19 years (average age 13.48 ± 3.32 years) from the NHANES 2007-2010. Multivariate linear regression analyses were utilized to detect the association between CDAI and total spine, femur neck, and total femur BMD, adjusting for confounders including age, race/ethnicity, sex, poverty income ratio (PIR), body mass index (BMI), serum phosphorus and calcium. Stratified analyses and interaction tests were performed to examine the stability of the results. The weighted characteristics showed that subjects in the fourth CDAI quartile were more likely to be older, men, and Non-Hispanic White. They have higher values of serum total calcium and phosphorus. After adjusting all confounders, CDAI was positively associated with the total spine (β = 0.0031 95% CI 0.0021-0.0040), total femur (β = 0.0039 95% CI 0.0028-0.0049), and femur neck BMD (β = 0.0031 95% CI 0.0021-0.0040) in children and adolescents. Furthermore, we found no interaction effects between different race/ethnicity, age, and sex groups. Our findings suggest that dietary intake of multiple antioxidants was positively associated with BMD in children and adolescents. These findings provide valuable evidence for improving bone health in the early stages of life. However, more prospective studies are required to validate our findings and their causal relationship.

Vitamin C Deficiency Deteriorates Bone Microarchitecture and Mineralization in a Sex-Specific Manner in Adult Mice

Vitamin C (VitC) is essential for bone health, and low VitC serum levels increase the risk for skeletal fractures. If and how VitC affects bone mineralization is unclear. Using micro-computed tomography (μCT), histologic staining, as well as quantitative backscattered electron imaging (qBEI), we assessed the effects of VitC on femoral structure and microarchitecture, bone formation, and bone mineralization density distribution (BMDD) in the VitC incompetent Gulo-/- mouse model and wild-type mice. In particular, VitC-supplemented, 20-week-old mice were compared with age-matched counterparts where dietary VitC intake was excluded from week 15. VitC depletion in Gulo-/- mice severely reduced cortical thickness of the diaphyseal shaft and bone volume around the growth plate (eg, bone volume of the primary spongiosa -43%, p < 0.001). Loss of VitC also diminished the amount of newly formed bone tissue as visualized by histology and calcein labeling of the active mineralization front. BMDD analysis revealed a shift to higher calcium concentrations upon VitC supplementation, including higher average (~10% increase in female VitC deficient mice, p < 0.001) and peak calcium concentrations in the epiphyseal and metaphyseal spongiosa. These findings suggest higher bone tissue age. Importantly, loss of VitC had significantly more pronounced effects in female mice, indicating a higher sensitivity of their skeleton to VitC deficiency. Our results reveal that VitC plays a key role in bone formation rate, which directly affects mineralization. We propose that low VitC levels may contribute to the higher prevalence of bone-degenerative diseases in females and suggest leveraging this vitamin against these conditions. © 2023 American Society for Bone and Mineral Research (ASBMR).

Blackcurrants Reduce the Risk of Postmenopausal Osteoporosis: A Pilot Double-Blind, Randomized, Placebo-Controlled Clinical Trial

Beneficial effects of blackcurrant supplementation on bone metabolism in mice has recently been demonstrated, but no studies are available in humans. The current study aimed to examine the dose-dependent effects of blackcurrant in preventing bone loss and the underlying mechanisms of action in adult women. Forty peri- and early postmenopausal women were randomly assigned into one of three treatment groups for 6 months: (1) a placebo (control group, n = 13); (2) 392 mg/day of blackcurrant powder (low blackcurrant, BC, group, n = 16); and (3) 784 mg/day of blackcurrant powder (high BC group, n = 11). The significance of differences in outcome variables was tested by repeated-measures ANOVA with treatment and time as between- and within-subject factors, respectively. Overall, blackcurrant supplementation decreased the loss of whole-body bone mineral density (BMD) compared to the control group (p < 0.05), though the improvement of whole-body BMD remained significant only in the high BC group (p < 0.05). Blackcurrant supplementation also led to a significant increase in serum amino-terminal propeptide of type 1 procollagen (P1NP), a marker of bone formation (p < 0.05). These findings suggest that daily consumption of 784 mg of blackcurrant powder for six months mitigates the risk of postmenopausal bone loss, potentially through enhancing bone formation. Further studies of larger samples with various skeletal conditions are warranted to confirm these findings.

Suboptimal Plasma Vitamin C Is Associated with Lower Bone Mineral Density in Young and Early Middle-Aged Men: A Retrospective Cross-Sectional Study

Background: This study was conducted to evaluate associations between bone mineral density (BMD) and four selected circulating nutrients, particularly vitamin C, among adults aged 20−49 years. Methods: In this retrospective cross-sectional study, the lumbar spine BMD of 866 men and 589 women were measured by dual-energy X-ray absorptiometry and divided into tertiles, respectively. Logistic regressions were used to identify the predictors of low BMD by comparing subjects with the highest BMD to those with the lowest. Results: Multivariate logistic regressions identified suboptimal plasma vitamin C (adjusted odds ratio (AOR) 1.64, 95% confidence interval (CI) 1.16, 2.31), suboptimal serum vitamin B12 (AOR 2.05, 95% CI 1.02, 4.12), and low BMI (BMI < 23) (AOR 1.68, 95% CI 1.12, 2.53) as independent predictors for low BMD in men. In women, low BMI was the only independent predictor for low BMD. Plasma vitamin C, categorized as suboptimal (≤8.8 mg/L) and sufficient (>8.8 mg/L), was positively significantly correlated with the lumbar spine BMD in men, but there was no association in women. Conclusions: Plasma vitamin C, categorized as suboptimal and sufficient, was positively associated with the lumbar spine BMD in young and early middle-aged men. A well-designed cohort study is needed to confirm the findings.

Pain in Hemophilia: Unexplored Role of Oxidative Stress

Hemophilia is the most common X-linked bleeding diathesis caused by the genetic deficiency of coagulation factors VIII or IX. Despite treatment advances and improvements in clinical management to prevent bleeding, management of acute and chronic pain remains to be established. Repeated bleeding of the joints leads to arthropathy, causing pain in hemophilia. However, mechanisms underlying the pathogenesis of pain in hemophilia remain underexamined. Herein, we describe the novel perspectives on the role for oxidative stress in the periphery and the central nervous system that may contribute to pain in hemophilia. Specifically, we cross examine preclinical and clinical studies that address the contribution of oxidative stress in hemophilia and related diseases that affect synovial tissue to induce acute and potentially chronic pain. This understanding would help provide potential treatable targets using antioxidants to ameliorate pain in hemophilia.

Evaluation of the Effects of Favipiravir Combined with Vitamin C on Alveolar Bone in Rats

Introduction: Favipiravir and Vitamin C (Vit C) were used together in the treatment of the COVID-19 pandemic. However, the effects of favipiravir on the periodontium are still unknown. Therefore, the aim of this study was to investigate the effects of Favipiravir and Vit C treatment on alveolar bone metabolism. Experimental: Fifty healthy adult male Sprague-Dawley rats (2–3 months old) were randomly divided into five equal groups (n = 10): Control, Favi 20, Favi 100, Favi 20+Vit C, Favi 100+Vit C. Favipiravir (20 mg/kg and 100 mg/kg, i.m.) and Vit C (150 mg/kg/day, oral) were administered to the rats for 14 days. Alveolar bone loss (ABL) and histopathological changes were examined using a light microscope. Immunohistochemistry was used to determine levels of receptor activator of nuclear factor kappa-B ligand (RANKL), caspase-3, bone morphogenic protein 2 (BMP-2) and alkaline phosphatase (ALP) in the bone tissues. Results: Favipiravir increased the levels of RANKL and caspase-3 expression but decreased BMP-2 and ALP levels in a dose-dependent manner. Favi 20+Vit C and Favi 100 +Vit C groups showed decreased RANKL and caspase-3 levels in addition to increased BMP-2 and ALP levels. Conclusion: Favipiravir can cause histopathological damage to the periodontium, but administration of favipiravir combined with Vit C can provide a protective effect against this damage.

Antioxidant Activity of Natural Samwirin A: Theoretical and Experimental Insights

Samwirin A (SW), a natural compound isolated from Sambucus williamsii or Rourea harmandiana, is known to exhibit potent antiosteoporosis activity and promote cell proliferation in rat osteoblast-like UMR 106 cells. Antiosteoporosis activity suggests that the compound must also exhibit antioxidant activity but this has not been studied thus far. In the present study, the antioxidant activity of SW was examined by experimental and computational studies. It was found that SW exhibits good hydroperoxyl scavenging activity, particularly in water at physiological pH (k overall = 1.01 × 107 M-1 s-1). The single-electron transfer mechanism defines the HOO• + SW reaction in water, while the activity in the lipid medium is moderate and it follows the formal hydrogen transfer mechanism. The rate constant of the HOO• scavenging reaction in the aqueous solution is about 78 times higher than the reference compound Trolox. The computational results are in line with experimental data underscoring that SW is a promising radical scavenger in aqueous media at physiological pH.

Sufficient Plasma Vitamin C Is Related to Greater Bone Mineral Density among Postmenopausal Women from the Boston Puerto Rican Health Study

BACKGROUND

Vitamin C may benefit bone as an antioxidant.

OBJECTIVES

This cross-sectional study evaluated associations between dietary, supplemental, and plasma vitamin C with bone mineral density (BMD) among Puerto Rican adults.

METHODS

Diet was assessed by food-frequency questionnaire (n = 902); plasma vitamin C, measured in fasting blood (n = 809), was categorized as sufficient (≥50 μmol/L), insufficient (20-49 μmol/L), or low (<20 μmol/L). Associations between vitamin C and BMD (measured by DXA) were tested, with false discovery rate correction for multiple comparisons, and interactions by smoking, sex, and estrogen status. Least-squares mean BMDs were compared across tertiles of diet and plasma vitamin C.

RESULTS

Participants' mean age was 59 ± 7 y (range: 46-78 y), 72% were women, mean dietary vitamin C was 95 ± 62 mg/d, and plasma vitamin C ranged from 1.7 to 125 μmol/L. No associations were observed between dietary vitamin C and BMD (P-value range: 0.48-0.96). BMD did not differ by vitamin C supplement use (P-value range: 0.07-0.29). Total femur BMD was higher (P = 0.04) among plasma vitamin C-sufficient participants (mean: 1.06; 95% CI: 1.035, 1.076 g/cm2) compared with low plasma vitamin C participants (1.026; 0.999, 1.052 g/cm2) in adjusted models. Findings at the trochanter were similar (P = 0.04). Postmenopausal women without estrogen therapy, with sufficient plasma vitamin C, showed greater total femur BMD (1.004 ± 0.014 g/cm2) compared to those with low plasma vitamin C (0.955 ± 0.017 g/cm2; P = 0.001). Similar findings were observed at the trochanter (P < 0.001). No significant associations were observed among premenopausal women or those with estrogen therapy or men. Interactions with smoking status were not significant.

CONCLUSIONS

Dietary vitamin C was not associated with BMD. Low plasma vitamin C, compared with sufficiency, was associated with lower hip BMD, particularly among postmenopausal women without estrogen therapy. Future research is needed to determine whether vitamin C status is associated with change in BMD or reduction in fracture risk.

Oxidative Stress and Osteoporosis

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Oxidative stress has been implicated as a causative factor in many disease states, possibly including the diminished bone mineral density in osteoporosis.

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Understanding the effects of oxidative stress on the development of osteoporosis may lead to further research improving preventative and therapeutic measures that can combat this important contributor to morbidity and mortality worldwide.

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A diet rich in whole plant foods with high antioxidant content along with antioxidant-preserving lifestyle changes may improve bone mineral density and reduce the risk of fragility-related fractures. While it is not explicitly clear if antioxidant activity is the effector of this change, the current evidence supports this possibility.

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Supplementation with isolated antioxidants may also provide some osteoprotective benefits, but whole plant food-derived antioxidants potentially have more overall benefits. Larger-scale clinical trials are needed to give credence to definitive clinical recommendations.

Natural medicine delivery from biomedical devices to treat bone disorders: A review

With an increasing life expectancy and aging population, orthopedic defects and bone graft surgeries are increasing in global prevalence. Research to date has advanced the understanding of bone biology and defect repair mechanism, leading to a marked success in the development of synthetic bone substitutes. Yet, the quest for functionalized bone grafts prompted the researchers to find a viable alternative that regulates cellular activity and supports bone regeneration and healing process without causing serious side-effects. Recently, researchers have introduced natural medicinal compounds (NMCs) in bone scaffold that enables them to release at a desirable rate, maintains a sustained release allowing sufficient time for tissue in-growth, and guides bone regeneration process with minimized risk of tissue toxicity. According to World Health Organization (WHO), NMCs are gaining popularity in western countries for the last two decades and are being used by 80% of the population worldwide. Compared to synthetic drugs, NMCs have a broader range of safety window and thus suitable for prolonged localized delivery for bone regeneration. There is limited literature focusing on the integration of bone grafts and natural medicines that provides detailed scientific evidences on NMCs, their toxic limits and particular application in bone tissue engineering, which could guide the researchers to develop functionalized implants for various bone disorders. This review will discuss the emerging trend of NMC delivery from bone grafts, including 3D-printed structures and surface-modified implants, highlighting the significance and potential of NMCs for bone health, guiding future paths toward the development of an ideal bone tissue engineering scaffold. STATEMENT OF SIGNIFICANCE: To date, additive manufacturing technology provids us with many advanced patient specific or defect specific bone constructs exhibiting three-dimensional, well-defined microstructure with interconnected porous networks for defect-repair applications. However, an ideal scaffold should also be able to supply biological signals that actively guide tissue regeneration while simultaneously preventing post-implantation complications. Natural biomolecules are gaining popularity in tissue engineering since they possess a safer, effective approach compared to synthetic drugs. The integration of bone scaffolds and natural biomolecules exploits the advantages of customized, multi-functional bone implants to provide localized delivery of biochemical signals in a controlled manner. This review presents an overview of bone scaffolds as delivery systems for natural biomolecules, which may provide prominent advancement in bone development and improve defect-healing caused by various musculoskeletal disorders.

Evidence of a Positive Link between Consumption and Supplementation of Ascorbic Acid and Bone Mineral Density

In animal models it has been shown that ascorbic acid (AA) is an essential cofactor for the hydroxylation of proline in collagen synthesis. However, there are still no precise indications regarding the role of AA in maintaining bone health in humans, so the aim of this narrative review was to consider state of the art on correlation between bone mineral density (BMD), AA dietary intake and AA blood levels, and on the effectiveness of AA supplement in humans. This review included 25 eligible studies. Fifteen studies evaluated correlations between AA intake and BMD: eight studies demonstrated a positive correlation between AA dietary intake and BMD in 9664 menopausal women and one significant interaction between effects of AA intake and hormone therapy. These data were also confirmed starting from adolescence (14,566 subjects). Considering studies on AA blood concentration and BMD, there are four (337 patients) that confirm a positive correlation. Regarding studies on supplementation, there were six (2671 subjects), of which one was carried out with AA supplementation exclusively in 994 postmenopausal women with a daily average dose of 745 mg (average period: 12.4 years). BMD values were found to be approximately 3% higher in women who took supplements.

Effects of Caffeic Acid and Its Derivatives on Bone: A Systematic Review

PURPOSE

Caffeic acid is a metabolite of hydroxycinnamate and phenylpropanoid, which are commonly synthesized by all plant species. It is present in various food sources that are known for their antioxidant properties. As an antioxidant, caffeic acid ameliorates reactive oxygen species, which have been reported to cause bone loss. Some studies have highlighted the effects of caffeic acid against bone resorption.

METHODS

A systematic review of the literature was conducted to identify relevant studies on the effects of caffeic acid on bone. A comprehensive search was conducted from July to November 2020 using PubMed, Scopus, Cochrane Library and Web of Science databases. Cellular, animal and human studies reporting the effects of caffeic acid, as a single compound, on bone cells or bone were considered.

RESULTS

The literature search found 226 articles on this topic, but only 24 articles met the inclusion criteria and were included in this review. The results showed that caffeic acid supplementation reduced osteoclastogenesis and bone resorption, possibly through its antioxidant potential and increased expression of osteoblast markers. However, some studies showed that caffeic acid did not affect bone resorption in ovariectomized rats and might impair bone mechanical properties in normal rats.

CONCLUSION

Caffeic acid potentially regulates the bone remodelling process by inhibiting osteoclastogenesis and bone resorption, as well as osteoblast apoptosis. Thus, it has medicinal values against bone diseases.

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.

Sustained release of vitamin C from PCL coated TCP induces proliferation and differentiation of osteoblast cells and suppresses osteosarcoma cell growth

The objective of this study is to understand the effect of sustained release of vitamin C from β-tricalcium phosphate (β-TCP) scaffold on proliferation, viability and differentiation of human fetal osteoblast cells (hFOB). The influence of pH, drug concentration, and presence of polymer on the sustained release of vitamin C from polycaprolactone (PCL) coated β-TCP scaffolds are studied. Prolonged and sustained release of vitamin C, over 60 days is observed in PCL coated β-TCP scaffolds compared to uncoated scaffolds. Presence of PCL helps to minimize the burst release of vitamin C from β-TCP scaffolds in the initial 24 h of release. To evaluate the osteogenic potential of vitamin C incorporated β-TCP scaffolds, osteoblast cells are cultured and cell morphology, proliferation, viability, and differentiation are assessed. Morphological characterization shows layer like osteoblast cell attachment in the presence of vitamin C compared to the control. MTT cell viability assay shows 2 folds increase in osteoblast cell density in the presence of vitamin C after 3,7 and 11 days of culture. Furthermore, increased ALP activity at 11 days of culture indicates the possible role of vitamin C on osteoblast differentiation. Additionally, a preliminary study shows vitamin C loaded scaffolds suppress osteosarcoma (MG-63) cell proliferation to 4 folds after 3 days compared to control. These results show a sustained release of vitamin C from PCL coated β-TCP scaffolds improve proliferation, viability, and differentiation of osteoblasts cell as well as mitigate osteosarcoma cell proliferation, suggesting its potential application as synthetic bone graft substitutes in tissue engineering application.

Impact of vitamin C on teriparatide treatment in the improvement of bone mineral density, strength, and quality in vitamin C-deficient rats

Age-related decreases in serum levels of vitamin C (VC) may negatively affect the efficacy of anti-osteoporotic pharmacotherapy. The purpose of this study was to evaluate the effects of VC and teriparatide (TPTD) on bone mineral density (BMD), strength, and quality in VC-deficient osteogenic disorder Shionogi (ODS) rats. Six-month-old female ODS rats were divided into an untreated ODS control group, a VC group, a TPTD group, and a VC + TPTD group, based on the administration of VC and TPTD (n = 10 each). VC was given as 2.0 mg/ml supplemented water. TPTD was administered subcutaneously once a week at 30 µg/kg body weight. After 12 weeks of treatment, BMDs of the femur and lumbar spine, bone strengths of the femoral diaphysis and metaphysis, and cancellous bone quality of proximal tibiae as estimated by Fourier transform infrared spectroscopy (FTIR) were compared between groups. Compared to the ODS control group, the VC group showed significantly higher total femoral BMD, but the TPTD group showed significantly higher femoral and lumbar spinal BMD, maximum load of femoral metaphysis, and hydroxyapatite (HA) crystallinity by FTIR (p < 0.05). In addition to the increases shown in the TPTD group, the VC + TPTD group also showed significantly higher stiffness of the femoral diaphysis and breaking energy of the femoral metaphysis compared to the ODS control group (p < 0.05). These results indicated that TPTD alone increased cancellous/cortical BMD and cancellous bone strength with improvement of HA crystallinity in ODS rats, but addition of VC supplementation further improved cortical bone strength.

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.

Vitamin C Activates Osteoblastogenesis and Inhibits Osteoclastogenesis via Wnt/β-Catenin/ATF4 Signaling Pathways

This study evaluated the effects of vitamin C on osteogenic differentiation and osteoclast formation, and the effects of vitamin C concentration on bone microstructure in ovariectomized (OVX) Wistar rats. Micro-computed tomography analysis revealed the recovery of bone mineral density and bone separation in OVX rats treated with vitamin C. Histomorphometrical analysis revealed improvements in the number of osteoblasts, osteoclasts, and osteocytes; the osteoblast and osteoclast surface per bone surface; and bone volume in vitamin C-treated OVX rats. The vitamin C-treated group additionally displayed an increase in the expression of osteoblast differentiation genes, including bone morphogenetic protein-2, small mothers against decapentaplegic 1/5/8, runt-related transcription factor 2, osteocalcin, and type I collagen. Vitamin C reduced the expression of osteoclast differentiation genes, such as receptor activator of nuclear factor kappa-B, receptor activator of nuclear factor kappa-B ligand, tartrate-resistant acid phosphatase, and cathepsin K. This study is the first to show that vitamin C can inhibit osteoporosis by promoting osteoblast formation and blocking osteoclastogenesis through the activation of wingless-type MMTV integration site family/β-catenin/activating transcription factor 4 signaling, which is achieved through the serine/threonine kinase and mitogen-activated protein kinase signaling pathways. Therefore, our results suggest that vitamin C improves bone regeneration.

NADPH oxidases in bone homeostasis and osteoporosis

Bone is a tissue with constant remodeling, where osteoblasts form and osteoclasts degrade bone. Both cell types are highly specialized in their function and both form from precursors and have to be replaced on a regular basis. This replacement represents one control level of bone homeostasis. The second important level would be the control of the function of osteoblasts and osteoclasts in order to keep the balance of bone -formation and -degradation. Both differentiation and control of cellular function are potentially redox sensitive processes. In fact, reactive oxygen species (ROS) are utilized by a wide range of cells for differentiation and control of cellular signaling and function. A major source of ROS is the family of NADPH oxidases. The sole function of those enzymes is the formation of ROS in a controlled and targeted manner. Importantly the members of the NADPH oxidase family differ in their localization and in the type and amount of ROS produced. Accordingly the impact of the members of the NADPH oxidase family on differentiation and function differs between cell types. This review will highlight the function of different NADPH oxidases in differentiation and function of bone cells and thereby will discuss the role of NADPH oxidases in bone homeostasis and osteoporosis.

β-Carotene prevents bone loss in hind limb unloading mice

β-Carotene has been reported to be useful to maintain a positive balance of bone turnover. However, the effects of β-carotene on bone loss remain to be elucidated in mice with hind limb unloading. Therefore, we investigated whether β-carotene prevented bone loss induced by skeletal hind limb unloading in mice. Female 8-week-old ddY mice were divided into six groups (n = 6–8 each) and subjected to: (1) normal housing, (2) sham unloading fed a control diet, (3) hind limb unloading fed a control diet, (4) hind limb unloading fed a 0.025% β-carotene-containing diet, (5) hind limb unloading fed a 0.05% β-carotene-containing diet, and (6) hind limb unloading fed a 0.25% β-carotene-containing diet. After 3 weeks, bone mineral density of the tibia was markedly reduced by unloading, which was prevented by 0.025% β-carotene. Histological analysis revealed a hind limb unloading-induced decrease in the calcified bone of the femur, which was slightly prevented by 0.025% β-carotene. The 0.025% β-carotene-containing diet increased the gene expression of osteoprotegerin in the bone marrow cells in unloading mice. These results suggest that a β-carotene-containing diet may preserve bone health in subjects with disabilities as well as in astronauts.

Antioxidant and Anti-Osteoporosis Activities of Chemical Constituents of the Stems of Zanthoxylum piperitum

Two new lignans, zanthoxyloside C (1) and zanthoxyloside D (2), together with nine known compounds comprising lignans (3-5), flavonoids (6-8), and phenolics (9-11), were isolated from the methanol extract of the stems of Zanthoxylum piperitum. All isolates were evaluated for their antioxidant and anti-osteoporotic activities using oxygen radical absorbance capacity (ORAC), cupric reducing antioxidant capacity (CUPRAC), and tartrate-resistant acid phosphatase (TRAP) assays. Compounds 7-10 showed peroxyl radical-scavenging capacities and 4, 6-7, and 9 showed reducing capacities. Moreover, compounds 3, 6-9, and 11 significantly suppressed TRAP activities. These results indicated that the stems of Z. piperitum could be an excellent source for natural antioxidant and anti-osteoporosis.

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.

Effect of anthocyanin-rich bilberry extract on bone metabolism in ovariectomized rats

Menopause is associated with increased oxidative stress, which serves a role, in part, in the pathogenesis of postmenopausal bone loss. Fruits and vegetables are rich in antioxidative nutrients and phytochemicals. Berries are a natural source of anthocyanins, and their intake may improve bone health. The aim of the present study was to determine the effect of an anthocyanin-rich bilberry extract (VME) on bone metabolism in an ovariectomized (Ovx) rat. Female Sprague-Dawley rats (12 weeks old) were randomly divided into the following four groups: Baseline, Sham, Ovx and Ovx+VME (n=8-12 rats per group). Rats in the Baseline group were sacrificed immediately, while those in the other groups were subjected to either sham operation (Sham) or bilateral Ovx (Ovx and Ovx+VME). Rats in the Ovx+VME group were administered VME daily at a dose of 500 mg/kg body weight. At 8 weeks after surgery, bone mass and bone histomorphometry were evaluated. The femur bone mineral density (BMD) in the Ovx group was significantly lower than that in the Sham group (P<0.01). Supplementation of VME in the Ovx rats did not result in an increase in BMD. Histomorphometric analyses revealed that Ovx resulted in decreased measures of bone volume and trabecular number and increased measures of osteoid volume, mineralizing surface and bone formation rates (all P<0.01), whereas VME had no significant effects on these parameters. The present findings indicate that VME did not alter bone metabolism in Ovx rats, suggesting that consumption of VME may not be helpful in preventing postmenopausal bone loss.

Oxidative stress in bone remodeling: role of antioxidants

ROS are highly reactive molecules which consist of a number of diverse chemical species, including radical and non-radical oxygen species. Oxidative stress occurs as a result of an overproduction of ROS not balanced by an adequate level of antioxidants. The natural antioxidants are: thiol compounds among which GSH is the most representative, and non-thiol compounds such as polyphenols, vitamins and also various enzymes. Many diseases have been linked to oxidative stress including bone diseases among which one of the most important is the osteoporosis. The redox state changes are also related to the bone remodeling process which allows the continuous bone regeneration through the coordinated action of bone cells: osteoclasts, osteoblasts and osteocytes. Changes in ROS and/or antioxidant systems seem to be involved in the pathogenesis of bone loss. ROS induce the apoptosis of osteoblasts and osteocytes, and this favours osteoclastogenesis and inhibits the mineralization and osteogenesis. Excessive osteocyte apoptosis correlates with oxidative stress causing an imbalance in favor of osteoclastogenesis which leads to increased turnover of bone remodeling and bone loss. Antioxidants either directly or by counteracting the action of oxidants contribute to activate the differentiation of osteoblasts, mineralization process and the reduction of osteoclast activity. In fact, a marked decrease in plasma antioxidants was found in aged or osteoporotic women. Some evidence shows a link among nutrients, antioxidant intake and bone health. Recent data demonstrate the antioxidant properties of various nutrients and their influence on bone metabolism. Polyphenols and anthocyanins are the most abundant antioxidants in the diet, and nutritional approaches to antioxidant strategies, in animals or selected groups of patients with osteoporosis or inflammatory bone diseases, suggest the antioxidant use in anti-resorptive therapies for the treatment and prevention of bone loss.

Integrative Medicine for Geriatric and Palliative Care

More than 80% of people in the United States who are older than 65 years have 1 or more chronic medical problems, and 50% have 2 or more. The cost of care for the elderly is at least 3 to 4 times that of younger populations and is rapidly growing, mostly because of a lack of preventive approaches and overly medicalized and fragmented care. This article summarizes the most up-to-date evidence for specific integrative modalities for common geriatric conditions, including falls, frailty, osteoporosis, and end-of-life palliative care.

Nutritional Aspects of Bone Health and Fracture Healing

INTRODUCTION

Fractures are quite common, especially among the elderly. However, they can increase in prevalence in younger ages too if the bone health is not good. This may happen as a result of bad nutrition.

METHODS

A customized, retrospective review of available literature was performed using the following keywords: bone health, nutrition, and fractures.

RESULTS

Insufficient intake of certain vitamins, particularly A and D, and other nutrients, such as calcium, may affect bone health or even the time and degree of bone healing in case of fracture. The importance of different nutrients, both dietary and found in food supplements, is discussed concerning bone health and fracture healing.

CONCLUSION

A healthy diet with adequate amounts of both macro- and micronutrients is essential, for both decreasing fracture risk and enhancing the healing process after fracture.

Calcium Bioavailability and Kinetics of Calcium Ascorbate and Calcium Acetate in Rats

The objective was to investigate the bioavailability and mechanism of calcium absorption of calcium ascorbate (ASC) and calcium acetate (AC). A series of studies was performed in adult Sprague-Dawley male rats. In the first study, each group of rats (n = 10/group) was assigned to one of the five test meals labeled with 45Ca: (i) 25 mg calcium as heated ASC or (ii) unheated ASC, (iii) 25 mg calcium as unheated AC, (iv) 3.6 mg Ca as unheated ASC, or (v) unheated AC. Femur uptake indicated better calcium bioavailability from ASC than AC t both calcium loads. A 5-min heat treatment partly reduced bioavailability of ASC. Kinetic studies were performed to further investigate the mechanism of superior calcium bioavailability from ASC. Two groups of rats (n = 10/group) received oral doses of 25 mg Ca as ASC or AC. Each dose contained 20 μCi 45Ca. Two additional groups of rats (n = 10/group) received an intravenous injection (iv) of 10 μCi 45Ca after receiving an unlabeled oral dose of 25 mg calcium as ASC or AC. Sequential blood samples were collected over 48 hrs. Urine and fecal samples were collected every 12 hrs for 48 hrs and were analyzed for total calcium and 45Ca content. Total calcium and 45Ca from serum, urine, and feces were fitted by a compartment kinetics model with saturable and nonsaturable absorption pathways by WinSAAM (Windows-based Simulation Analysis and Modeling). The difference in calcium bioavailability between the two salts was due to differences in saturable rather than passive intestinal absorption and not to endogenous secretion or calcium deposition rate. The higher bioavailability of calcium ascorbate was due to a longer transit time in the small intestine compared with ASC.

Relationship between bone mineral density and dietary intake of β-carotene, vitamin C, zinc and vegetables in postmenopausal Korean women: a cross-sectional study

Objective

To examine the relationship between nutritional intake and bone mineral density (BMD) in postmenopausal Korean women.

Methods

Dietary intake was recorded in postmenopausal Korean women using a semiquantitative questionnaire. The frequency of consumption of various food groups and nutrient intake were calculated. BMD T-scores were measured at the lumbar spine, femoral neck and total hip using dual-energy X-ray absorptiometry. Associations between T-scores and dietary intake were analysed using partial correlation coefficients and multiple linear regression analysis.

Results

A total of 189 postmenopausal women were included in the study. β-Carotene intake was positively correlated with the lumbar spine T-score. Sodium and vitamin C intake were positively associated and folate intake negatively associated with the femoral neck T-score. Sodium, zinc and vitamin C intake were positively correlated and potassium intake was negatively correlated with the total hip T-score. Vegetable intake showed a positive association with the femoral neck and total hip T-scores.

Conclusion

In postmenopausal Korean women, β-carotene, vitamin C, zinc and sodium intakes were positively associated with bone mass. Furthermore, frequency of vegetable consumption was positively associated with femoral neck and total hip T-scores.

Superoxide Dismutase 2 Polymorphisms and Osteoporosis in Asian Indians: A Genetic Association Analysis

Oxidative stress plays an important role in the development of osteoporosis. The present cross-sectional study focuses on mapping single nucleotide polymorphisms (SNPs) in the mitochondrial manganese superoxide dismutase (SOD2) gene in Asian Indians. The bone mineral density (BMD) of study subjects was assessed by dual x-ray absorptiometry. Individuals were classified as normal (n = 82) or osteoporotic (n = 98). Biochemical parameters such as vitamin D, total oxidant status (TOS) and SOD2 enzyme activity were estimated from plasma samples. Semi-quantitative PCR was carried out using GAPDH as an endogenous control. Genomic DNA was isolated from whole blood and SNPs were evaluated by PCR sequencing. Thirteen SNPs are reported in the examined region of the SOD2 gene, out of which in our samples SNPs rs5746094 and rs4880 were found to be polymorphic. Allele G of rs5746094 (intronic) and allele C of rs4880 (exonic) are significantly higher in the osteoporotic individuals. Presence of allele C of rs4880 and increased level of TOS among osteoporotic individuals were found to be associated with disease risk.

Cross-sectional and prospective associations between dietary and plasma vitamin C, heel bone ultrasound, and fracture risk in men and women in the European Prospective Investigation into Cancer in Norfolk cohort

BACKGROUND

Vitamin C sufficiency may help prevent osteoporosis and fractures by mediating osteoclastogenesis, osteoblastogenesis, and bone collagen synthesis.

OBJECTIVE

We determined whether dietary intakes and plasma concentrations of vitamin C were associated with a heel ultrasound and hip and spine fracture risks in older men and women.

DESIGN

Participants were recruited from the European Prospective Investigation into Cancer in Norfolk study with 7-d diet diary estimates of vitamin C intake and plasma concentrations. A random subset (4000 of 25,639 subjects) was available for the cross-sectional (ultrasound) study of broadband ultrasound attenuation (BUA) and velocity of sound (VOS), which were determined during the second health examination. The prospective (fracture) study was a case-cohort sample of all participants with a fracture up to March 2009 and the random subset (n = 5319). ANCOVA-determined associations between quintiles of vitamin C intake and plasma status with adjusted BUA and VOS and adjusted Prentice-weighted Cox proportional HRs were calculated for fracture risk.

RESULTS

Women were 58% of the population (39-79 y old), and the median follow-up was 12.6 y (range: 0-16 y). Positive associations across all quintiles of vitamin C intake but not plasma status were significant for VOS in men (β = 2.47 m/s, P = 0.008) and BUA in women (β = 0.82 dB/MHz, P = 0.004). Vitamin C intake was not associated with fracture risk, but there was an inverse association with plasma concentrations in men, with quintile 4 having significantly lower risks of hip fractures (HR: 0.35; 95% CI: 0.16, 0.80) and spine fractures (HR: 0.26; 95% CI: 0.10, 0.69) than quintile 1.

CONCLUSIONS

Higher vitamin C intake was significantly associated with higher heel ultrasound measures in men and women, and higher plasma vitamin C concentrations were significantly associated with reduced fracture risk in men only. Our findings that vitamin C intake and status were inconsistently associated with bone health variables suggest that additional research is warranted.

The Roles and Mechanisms of Actions of Vitamin C in Bone: New Developments

Vitamin C is an important antioxidant and cofactor that is involved in the regulation of development, function, and maintenance of several cell types in the body. Deficiencies in vitamin C can lead to conditions such as scurvy, which, among other ailments, causes gingivia, bone pain, and impaired wound healing. This review examines the functional importance of vitamin C as it relates to the development and maintenance of bone tissues. Analysis of several epidemiological studies and genetic mouse models regarding the effect of vitamin C shows a positive effect on bone health. Overall, vitamin C exerts a positive effect on trabecular bone formation by influencing expression of bone matrix genes in osteoblasts. Recent studies on the molecular pathway for vitamin C actions that include direct effects of vitamin C on transcriptional regulation of target genes by influencing the activity of transcription factors and by epigenetic modification of key genes involved in skeletal development and maintenance are discussed. With an understanding of mechanisms involved in the uptake and metabolism of vitamin C and knowledge of precise molecular pathways for vitamin C actions in bone cells, it is possible that novel therapeutic strategies can be developed or existing therapies can be modified for the treatment of osteoporotic fractures.

Favorable effect of dietary vitamin C on bone mineral density in postmenopausal women (KNHANES IV, 2009): discrepancies regarding skeletal sites, age, and vitamin D status

Dietary vitamin C intake showed significant positive associations with BMD in postmenopausal women, especially with vitamin D deficiency.

INTRODUCTION

Although there is a positive role of vitamin C in osteoblastogenesis, debate remains about the contribution of vitamin C to bone mineral density (BMD) in humans.

METHODS

Data were derived from the Fourth Korean National Health and Nutrition Examination Survey. Dietary information was assessed using a 24-h dietary recall questionnaire. BMD was measured by dual-energy X-ray absorptiometry at the lumbar and hip.

RESULTS

A total of 1,196 postmenopausal women aged 50 years and older were stratified into tertiles by daily dietary vitamin C intake. After adjusting for traditional confounders, dietary vitamin C intake tertile was significantly positively associated with BMD at all sites (R = 0.513 for lumbar spine (LS) and R = 0.657 for femoral neck (FN), P < 0.05 for each). The subjects with osteoporosis had significantly lower dietary vitamin C intake than did subjects without osteoporosis (74.4 ± 66.2 vs 94.1 ± 78.6 mg/day for LS and 65.5 ± 56.6 vs 94.3 ± 79.2 mg/day for FN, respectively, P < 0.001). The multiple-adjusted odds ratio for osteoporosis for dietary vitamin C <100 mg/day was 1.790 (95 % CI 1.333-2.405, P < 0.001). However, the significant association between vitamin C intake and BMD was only observed in subjects with vitamin D deficiency and aged 50-59 years or >70 years.

CONCLUSION

Dietary vitamin C intake was positively associated with BMD in postmenopausal women, and inadequate vitamin C intake could increase the risk of osteoporosis.

Dietary Approaches for Bone Health: Lessons from the Framingham Osteoporosis Study

Osteoporosis is characterized by systemic impairment of bone mass, strength, and microarchitecture, resulting in increased risk for fragility fracture, disability, loss of independence, and even death. Adequate nutrition is important in achieving and maintaining optimal bone mass, as well as preventing this debilitating disease. It is widely accepted that adequate calcium and vitamin D intake are necessary for good bone health; however, nutritional benefits to bone go beyond these two nutrients. This review article will provide updated information on all nutrients and foods now understood to alter bone health. Specifically, this paper will focus on related research from the Framingham Osteoporosis Study, an ancillary study of the Framingham Heart Study, with data on more than 5000 adult men and women.

Is there a role for vitamin C in preventing osteoporosis and fractures? A review of the potential underlying mechanisms and current epidemiological evidence

Osteoporosis and related fractures are a major global health issue, but there are few preventative strategies. Previously reported associations between higher intakes of fruits and vegetables and skeletal health have been suggested to be partly attributable to vitamin C. To date, there is some evidence for a potential role of vitamin C in osteoporosis and fracture prevention but an overall consensus of published studies has not yet been drawn. The present review aims to provide a summary of the proposed underlying mechanisms of vitamin C on bone and reviews the current evidence in the literature, examining a potential link between vitamin C intake and status with osteoporosis and fractures. The Bradford Hill criteria were used to assess reported associations. Recent animal studies have provided insights into the involvement of vitamin C in osteoclastogenesis and osteoblastogenesis, and its role as a mediator of bone matrix deposition, affecting both the quantity and quality of bone collagen. Observational studies have provided some evidence for this in the general population, showing positive associations between dietary vitamin C intake and supplements and higher bone mineral density or reduced fracture risk. However, previous intervention studies were not sufficiently well designed to evaluate these associations. Epidemiological data are particularly limited for vitamin C status and for fracture risk and good-quality randomised controlled trials are needed to confirm previous epidemiological findings. The present review also highlights that associations between vitamin C and bone health may be non-linear and further research is needed to ascertain optimal intakes for osteoporosis and fracture prevention.

The association of dietary quality and food group intake patterns with bone health status among Korean postmenopausal women: a study using the 2010 Korean National Health and Nutrition Examination Survey Data

BACKGROUND/OBJECTIVES

Osteoporosis and osteoporosis-related disease are drawing a lot of attention in Korea as one of the serious health problems. Bone health status may be influenced by the general dietary quality and dietary pattern.

SUBJECTS/METHODS

To determine the relationship between dietary quality and intake patterns and bone health status, the %RNI, NAR, DDS, and food group intake patterns were assessed according to their bone health status for 847 postmenopausal women using the 2010 KNHANES data after eliminating those of likely changing their diet under the advice of doctors or those taking estrogen.

RESULTS

Bone health became worse as dietary quality deteriorated. All NAR and %RNI values were highly associated with bone health levels and the consumption frequency of Ca sources, DDS and the food group intake patterns also confirmed the findings.

CONCLUSIONS

This study confirmed that dietary quality and dietary patterns were important for bone health. Nutritional education on eating foods from the five basic food groups has to be emphasized to prevent osteoporosis among older women.

Major nutrient patterns and bone mineral density among postmenopausal Iranian women

Our understanding of the influence of overall nutrient intake on bone mineral density (BMD) is limited because most studies to date have focused on the intakes of calcium, vitamin D, or a few isolated nutrients. Therefore, we examined the association of major nutrient patterns with BMD in a sample of postmenopausal Iranian women. In this cross-sectional study, 160 women aged 50-85 years were studied and their lumbar spine and femoral neck BMDs were measured using dual-energy X-ray absorptiometry. Dietary intakes were assessed using a validated 168-item food frequency questionnaire, and daily intakes of 30 nutrients were calculated. All nutrient intakes were energy adjusted by the residual method and were submitted to principal component factor analysis to identify major nutrient patterns. Overall, three major nutrient patterns were identified, among which only the first pattern, which was high in folate, total fiber, vitamin B6, potassium, vitamin A (as retinol activity equivalent), vitamin C, β-carotene, vitamin K, magnesium, copper, and manganese, had a significant association with BMD. After controlling for potential confounders, multivariate adjusted mean of the lumbar spine BMD of women in the highest tertile of the first pattern scores was significantly higher than those in the lowest tertile (mean difference 0.08; 95% confidence interval 0.02-0.15; P = 0.01). A nutrient pattern similar to pattern 1, which is associated with high intakes of fruits and vegetables, may be beneficial for bone health in postmenopausal Iranian women.

The role of oxidative stress in menopause

This review will discuss the concept of reproductive aging, which includes the definition of menopause, its symptoms, and predisposing conditions. It will elaborate upon the contributory factors implicated in the pathogenesis of menopause, focusing most prominently on oxidative stress. Specifically, this paper will explain how oxidative stress, in the form of free radicals and antioxidant deficiencies, has been directly linked to the decline of estrogen during reproductive aging. Additionally, this paper will elaborate upon the treatment options aimed at mitigating the menopausal symptoms and hormonal deficiencies that can lead to various disease processes. Treatment options such as hormonal therapy, antioxidant supplementation, and lifestyle modification have been explored for their effectiveness in treating and preventing the symptoms and sequelae of menopause. The majority of information in this review was obtained through PubMed and the National Library of Medicine. While most references in this paper are original research articles, a limited number of references are comprehensive reviews on the topic.

Update on nutrients involved in maintaining healthy bone

Osteoporosis is a leading cause of morbidity and mortality in the elderly and influences quality of life, as well as life expectancy. Currently, there is a growing interest among the medical scientists in search of specific nutrients and/or bioactive compounds of natural origin for the prevention of disease and maintenance of bone health. Although calcium and vitamin D have been the primary focus of nutritional prevention of osteoporosis, a recent research has clarified the importance of several additional nutrients and food constituents. Based on this review of the literature, supplementation with vitamins B, C, K, and silicon could be recommended for proper maintenance of bone health, although further clinical studies are needed. The results of studies on long-chain polyunsaturated fatty acids, potassium, magnesium, copper, selenium, and strontium are not conclusive, although studies in vitro and in animal models are interesting and promising.

Selenium protects bone marrow stromal cells against hydrogen peroxide-induced inhibition of osteoblastic differentiation by suppressing oxidative stress and ERK signaling pathway

Osteoporosis is a bone disease that leads to an increased risk of fracture. Oxidative stress may play a major role in the development of osteoporosis in part by inhibiting osteoblastic differentiation of bone marrow stromal cells (MSCs). Some evidence suggested that antioxidant selenium could prevent osteoporosis, but the underlying mechanism remains unclear. In this work, the effect of sodium selenite on H₂O₂-induced inhibition of osteoblastic differentiation of primary rat bone MSCs and the related mechanisms were examined. Pretreatment with selenite inhibited the adverse effect of H₂O₂ on osteoblastic differentiation of MSCs, based on alkaline phosphatase activity, gene expression of type I collagen and osteocalcin, and matrix mineralization. In addition, selenite pretreatment also suppressed the activation of extracellular signal-regulated kinase (ERK) induced by H₂O₂. The above effects were mediated by the antioxidant effect of selenite. Selenite enhanced the gene expression and activity of glutathione peroxidase, reversed the decreased total antioxidant capacity and reduced glutathione, and suppressed reactive oxygen species production and lipid peroxidation level in H₂O₂-treated MSCs. These results showed that selenite protected MSCs against H₂O₂-induced inhibition of osteoblastic differentiation through inhibiting oxidative stress and ERK activation, which provided, for the first time, the mechanistic explanation for the negative association of selenium status and risk of osteoporosis in terms of bone formation.

Vitamin C prevents hypogonadal bone loss

Epidemiologic studies correlate low vitamin C intake with bone loss. The genetic deletion of enzymes involved in de novo vitamin C synthesis in mice, likewise, causes severe osteoporosis. However, very few studies have evaluated a protective role of this dietary supplement on the skeleton. Here, we show that the ingestion of vitamin C prevents the low-turnover bone loss following ovariectomy in mice. We show that this prevention in areal bone mineral density and micro-CT parameters results from the stimulation of bone formation, demonstrable in vivo by histomorphometry, bone marker measurements, and quantitative PCR. Notably, the reductions in the bone formation rate, plasma osteocalcin levels, and ex vivo osteoblast gene expression 8 weeks post-ovariectomy are all returned to levels of sham-operated controls. The study establishes vitamin C as a skeletal anabolic agent.

Effect of sesamol on the pathophysiological changes induced by surgical menopause in rodents

OBJECTIVE

Estrogen deprivation after menopause is associated with increased oxidative stress. The present study was designed to study the role of sesamol (3,4-methylenedioxyphenol), a phenolic antioxidant and anti-inflammatory molecule, in oxidative stress-induced changes in three major affected organ systems, the central nervous system, the cardiovascular system and the skeletal system in ovariectomized rats, a widely used animal model of menopause.

DESIGN

Animals were divided into eight different groups (n = 6-8). Five groups underwent ovariectomy; starting from the 2nd day of ovariectomy, three of these groups received sesamol (2, 4, 8 mg/kg) and the fourth group was administered α-tocopherol (100 mg/kg) orally for 7 weeks. The fifth ovariectomized group did not receive any drug treatment. Rats in the naïve (non-operated) and sham-operated groups did not receive any drug treatment, while the eighth group consisted of naïve animals which were treated for 7 weeks with only sesamol 8 mg/kg orally daily. After 7 weeks, animals were subjected to testing of behavioral paradigms (elevated plus maze and Morris water maze for assessment of anxiety and memory, respectively) 24 h after the last dose. After behavioral studies, animals were sacrificed for various biochemical estimations.

RESULT

Administration of sesamol (2, 4, 8 mg/kg orally) to ovariectomized rats for 7 weeks significantly and dose-dependently improved memory, attenuated anxiety, decreased oxidative stress in brain, improved the serum lipid profile and reduced serum tumor necrosis factor-α levels when compared with ovariectomized control rats. Similar protective effects were observed in the case of the skeletal system studies. Sesamol increased the bone ash content and the mechanical stress parameters in treated groups.

CONCLUSION

The results emphasize the involvement of oxidative stress and inflammation in the development of ovariectomy-induced pathophysiological changes and point towards the therapeutic potential of sesamol in menopausal pathologies.

Virgin coconut oil supplementation prevents bone loss in osteoporosis rat model

Oxidative stress and free radicals have been implicated in the pathogenesis of osteoporosis. Therefore, antioxidant compounds have the potential to be used in the prevention and treatment of the disease. In this study, we investigated the effects of virgin coconut oil (VCO) on bone microarchitecture in a postmenopausal osteoporosis rat model. VCO is a different form of coconut oil as it is rich with antioxidants. Three-month-old female rats were randomly grouped into baseline, sham-operated, ovariectomized control (Ovx), and ovariectomized rats fed with 8% VCO in their diet for six weeks (Ovx+VCO). Bone histomorphometry of the right femora was carried out at the end of the study. Rats supplemented with VCO had a significantly greater bone volume and trabecular number while trabecular separation was lower than the Ovx group. In conclusion, VCO was effective in maintaining bone structure and preventing bone loss in estrogen-deficient rat model.

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.

Essential Nutrients for Bone Health and a Review of their Availability in the Average North American Diet

Osteoporosis and low bone mineral density affect millions of Americans. The majority of adults in North America have insufficient intake of vitamin D and calcium along with inadequate exercise. Physicians are aware that vitamin D, calcium and exercise are essential for maintenance of bone health. Physicians are less likely to be aware that dietary insufficiencies of magnesium, silicon, Vitamin K, and boron are also widely prevalent, and each of these essential nutrients is an important contributor to bone health. In addition, specific nutritional factors may improve calcium metabolism and bone formation. It is the authors' opinion that nutritional supplements should attempt to provide ample, but not excessive, amounts of factors that are frequently insufficient in the typical American diet.In contrast to dietary insufficiencies, several nutrients that support bone health are readily available in the average American diet. These include zinc, manganese, and copper which may have adverse effects at higher levels of intake. Some multivitamins and bone support products provide additional quantities of nutrients that may be unnecessary or potentially harmful.The purpose of this paper is to identify specific nutritional components of bone health, the effects on bone, the level of availability in the average American diet, and the implications of supplementation for each nutritional component. A summary of recommended dietary supplementation is included.