Iron is one of the essential mineral elements for the human body and this nutrient deficiency is a worldwide public health problem. Iron is essential in oxygen transport, participates in many enzyme systems in the body, and is an important trace element in maintaining basic cellular life activities. Iron also plays an important role in collagen synthesis and vitamin D metabolism. Therefore, decrease in intracellular iron can lead to disturbance in the activity and function of osteoblasts and osteoclasts, resulting in imbalance in bone homeostasis and ultimately bone loss. Indeed, iron deficiency, with or without anemia, leads to osteopenia or osteoporosis, which has been revealed by numerous clinical observations and animal studies. This review presents current knowledge on iron metabolism under iron deficiency states and the diagnosis and prevention of iron deficiency and iron deficiency anemia (IDA). With emphasis, studies related to iron deficiency and bone loss are discussed, and the potential mechanisms of iron deficiency leading to bone loss are analyzed. Finally, several measures to promote complete recovery and prevention of iron deficiency are listed to improve quality of life, including bone health.

Osteoporosis (OP) is a metabolic bone disorder characterized by low bone mass and deterioration of micro-architectural bone tissue. The most common type of OP is postmenopausal osteoporosis (PMOP), with fragility fractures becoming a global burden for women. Recently, the gut microbiota has been connected to bone metabolism. The aim of this study was to characterize the gut microbiota signatures in PMOP patients and controls. Fecal samples from 21 PMOP patients and 37 controls were collected and analyzed using amplicon sequencing of the V3-V4 regions of the 16S rRNA gene. The bone mineral density (BMD) measurement and laboratory biochemical test were performed on all participants. Two feature selection algorithms, maximal information coefficient (MIC) and XGBoost, were employed to identify the PMOP-related microbial features. Results showed that the composition of gut microbiota changed in PMOP patients, and microbial abundances were more correlated with total hip BMD/T-score than lumbar spine BMD/T-score. Using the MIC and XGBoost methods, we identified a set of PMOP-related microbes; a logistic regression model revealed that two microbial markers (Fusobacteria and Lactobacillaceae) had significant abilities in disease classification between the PMOP and control groups. Taken together, the findings of this study provide new insights into the etiology of OP/PMOP, as well as modulating gut microbiota as a therapeutic target in the diseases. We also highlight the application of feature selection approaches in biological data mining and data analysis, which may improve the research in medical and life sciences.

Osteoporosis (OP) is a prevalent skeletal disorder characterized by decreased bone mineral density (BMD) and increased fracture risk. The advancements in omics technologies—genomics, transcriptomics, proteomics, and metabolomics—have provided significant insights into the molecular mechanisms driving OP. These technologies offer critical perspectives on genetic predispositions, gene expression regulation, protein signatures, and metabolic alterations, enabling the identification of novel biomarkers for diagnosis and therapeutic targets. This review underscores the potential of these multi-omics approaches to bridge the gap between basic research and clinical applications, paving the way for precision medicine in OP management. By integrating these technologies, researchers can contribute to improved diagnostics, preventative strategies, and treatments for patients suffering from OP and related conditions.

There are numerous studies that investigate the effects of static magnetic fields (SMFs) on osteoblasts and osteoclasts. However, although osteocytes are the most abundant cell type in bone tissue, there are few studies on the biological effects of osteocytes under magnetic fields. Iron is a necessary microelement that is involved in numerous life activities in cells. Studies have shown that high static magnetic fields (HiSMF) can regulate cellular iron metabolism. To illustrate the effect of HiSMF on activities of osteocytes, and whether iron is involved in this process, HiSMF of 16 tesla (T) was used, and the changes in cellular morphology, cytoskeleton, function-related protein expression, secretion of various cytokines, and iron metabolism in osteocytes under HiSMF were studied. In addition, the biological effects of HiSMF combined with iron preparation and iron chelator on osteocytes were also investigated. The results showed that HiSMF promoted cellular viability, decreased apoptosis, increased the fractal dimension of the cytoskeleton, altered the secretion of cytokines, and increased iron levels in osteocytes. Moreover, it was found that the biological effects of osteocytes under HiSMF are attenuated or enhanced by treatment with a certain concentration of iron. These data suggest that HiSMF-regulated cellular iron metabolism may be involved in altering the biological effects of osteocytes under HiSMF exposure.

Background: Eldecalcitol (ELD) and denosumab are some of the most common therapeutic options for osteoporosis management. ELD effectively increases bone mineral density (BMD) in osteoporotic patients, independent of baseline vitamin D status or calcium intake. However, the efficacy of denosumab combined with either ELD or native vitamin D plus calcium in postmenopausal Chinese women with osteoporosis has not been established. Methods: In this single-center, randomized, open-label, active-controlled clinical trial, postmenopausal women with osteoporosis (defined as a BMD T-score ≤ −2.5 at the lumbar spine [LS], total hip [TH], or femoral neck [FN], or low bone mass with fragility fracture history) were enrolled from Xi’an Honghui Hospital in China and randomized 1:1 to two 12-month treatment regimens: the ELD group received ELD (0.75 μg orally daily) combined with denosumab (60 mg subcutaneously every 6 months), while the control group received the same denosumab regimen plus native vitamin D (800 IU orally daily) and calcium (600 mg orally daily). The primary endpoint was the 12-month percent change in LS BMD from baseline. Secondary endpoints included changes in FN- and TH-BMD from baseline, bone turnover markers, serum parathyroid hormone, quality of life, and the incidence of new fractures. Results: Of the 100 randomized participants, 45 in the ELD group and 46 in the control group were included in the efficacy analysis. After 12 months of treatment, LS-BMD increased significantly in both groups (both p < 0.05), with a greater increase in the ELD group than in the control group (6.75% vs. 4.99%), yielding a statistically significant between-group least-squares mean difference of 1.75% (95% CI, 0.10 to 3.41; p = 0.038). The reduction in serum β-CTX was significantly smaller in the ELD group than in the control group at 3 months (91.00% vs. 93.62%, p = 0.002), with no significant between-group differences thereafter. Seven fractures were reported (one non-vertebral in the ELD group; one vertebral and five non-vertebral in the control group). No significant between-group differences in FN- or TH-BMD, quality of life, or overall adverse event rates were observed. Both regimens were generally well-tolerated, without clinically meaningful calcium-related safety signals. Conclusions: Combination therapy with denosumab and eldecalcitol improved LS-BMD more effectively than denosumab with native vitamin D and calcium in postmenopausal Chinese women with osteoporosis. Clinical trial number: ClinicalTrials.gov identifier NCT05884372, registered on 1 June 2023.