Impact of calcium and vitamin D insufficiencies on serum parathyroid hormone and bone mineral density: analysis of the fourth and fifth Korea National Health and Nutrition Examination Survey (KNHANES IV-3, 2009 and KNHANES V-1, 2010)

Strategies for preventing bone loss in populations with insufficient calcium and vitamin D intake

Calcium and vitamin D are essential nutrients for maintaining skeletal health, yet deficiencies in these nutrients are particularly widespread in regions such as Asia and Africa. Inadequate intake of these nutrients in these areas has been associated with diminished bone integrity and a rising incidence of osteoporosis. This review examines the underlying mechanisms of bone loss driven by calcium and vitamin D deficiencies, emphasizing their crucial roles in bone metabolism. It also presents strategies to improve nutrient intake, such as fortification of staple foods and supplementation, along with lifestyle modifications including increased physical activity, sun exposure, and dietary education, to prevent bone loss effectively. Special consideration is given to vulnerable populations, including older adults, individuals with limited sun exposure, and those with dietary restrictions, who are at higher risk of deficiency. The review further evaluates public health strategies, including government-initiated fortification and educational programs, as essential measures for tackling widespread nutrient deficiencies. Lastly, it explores future avenues for addressing calcium and vitamin D deficiencies, including the potential role of digital health tools, personalized nutrition, and innovative public health policies to alleviate the global burden of bone-related diseases.

Accelerated bone loss in late reproductive-aged and perimenopausal women with vitamin D insufficiency

INTRODUCTION

The association between serum vitamin D levels and bone mineral density (BMD) varies by race and gender. This study aimed to evaluate this relationship between serum vitamin D levels and BMD, and changes of BMD over time in Korean women.

MATERIALS AND METHODS

We analyzed data from 586 generally healthy Korean women aged 29-79 who underwent health check-ups at Seoul National University Gangnam Center between 2010 and 2011 (baseline measurement) and 2015-2016 (follow-up). Dual energy X-ray absorptiometry (DEXA) and serum 25-hydroxyvitamin D (25OH-D) level measurements were conducted. We assessed the association between serum 25OH-D levels and BMD, as well as changes in BMD over time.

RESULTS

The mean age of participants was 51.3 ± 7.9 years, with a mean follow-up interval of 4.6 ± 0.7 years, and mean serum 25OH-D level of 20.6 ± 8.5 ng/ml. Baseline serum 25OH-D levels did not correlate with BMD values at the lumbar spine, femoral neck, or total femur, nor with changes in BMD over time. A significant negative association was found between perimenopausal status and BMD changes at all sites, and between premenopausal status and lumbar bone mass, compared to postmenopausal status in the 25OH-D < 20 ng/ml group. This association was not observed in women with higher serum 25OH-D levels.

CONCLUSIONS

Serum 25OH-D levels did not correlate with BMD levels or changes in BMD overall. However, in late reproductive-aged and perimenopausal women with serum 25OH-D insufficiency, there was a significant association with accelerated bone loss.

Persistent Calcium Inadequacy in Korean Adults over 20 Years: Analysis of the 1998-2018 Korea National Health and Nutrition Examination Survey

Calcium inadequacy in Asian populations has been well documented, but whether it has improved over time remains uncertain. We analyzed dietary calcium intake and its association with osteoporosis prevalence over a 20-year period in 48,653 adults (21,932 men and 26,721 women, aged 19 years and older) in Korea, using data from the first to the seventh Korea National Health and Nutrition Examination Survey (1998-2018). Over the past 20 years, Korean adults consistently fell short of the recommended dietary calcium intake, with women and older adults particularly affected, typically consuming only 40-80% of the recommended levels. The 30-49 age group had the highest calcium intake (497-568 mg/day), while those aged 75+ had the lowest (319-457 mg/day). A significant inverse relationship was found between calcium intake and osteoporosis risk, with lower calcium intake associated with higher odds of developing osteoporosis, as determined by both physician diagnoses and bone mineral density measurements (p < 0.001). Notably, over the past 20 years, 68-70% of dietary calcium consistently came from plant-based foods. This study strongly emphasizes the urgent need to enhance calcium-rich food availability and implement targeted interventions to increase calcium intake among those most affected by inadequacy, particularly the elderly and women. Further research with recent data would be valuable for understanding current intake levels and evolving nutritional needs.

Home Meal Replacement Fortified with Eggshell Powder and Vitamin D Prevents Bone Loss in Postmenopausal Women: A Randomized, Double-Blind, Controlled Study

Calcium and vitamin D deficiencies have been ongoing problems in Koreans due to a lack of food sources of calcium and vitamin D. Postmenopausal women aged 50 to 64 years (n = 25) were randomly assigned to consume three home meal replacements (HMRs)/week with (treatment) and without (control) eggshell powder and vitamin D for 6 months. Additionally, subjects who agreed to continue the study consumed the same three HMRs/week for an additional 6 months in this randomized double-blind study. We confirmed the high compliance of the study participants by analyzing carotenoids, the bioactive substances of HMRs, in the blood. The treatment group consumed an additional 261 mg/d of calcium and 10.3 μg/d of vitamin D from the HMRs, thus meeting the recommended intakes of calcium and vitamin D for Koreans. As a result of consuming fortified HMRs for 6 months, the decline in femoral neck bone density was significantly reduced in the treatment group (p = 0.035). This study indicates that inexpensive eggshell powder may be a good source of calcium for populations with low consumption of milk and dairy products. Additionally, functional HMRs fortified with eggshell powder and vitamin D can be a good dietary strategy for bone health.

Effects of Menaquinone-7 on the Bone Health of Growing Rats under Calcium Restriction: New Insights from Microbiome-Metabolomics

Insufficient calcium intake during growth is a global public health concern. The aim of this study was to investigate the effects of dietary menaquinone-7 (MK-7) on bone accrual in growing Sprague-Dawley rats under calcium restriction. Following 13 weeks of treatment, various bone quality parameters, including microarchitecture, were measured. Fecal and cecal samples were subjected to microbiome (16S rRNA gene sequencing) analyses, while metabolomics analysis of the cecum and humerus samples was analyzed based on UHPLC-Q/TOF-MS. We found that calcium deficiency diminished the richness of the microbiome and disrupted microbiome composition, accompanied by an elevation in the relative abundance of Parasutterella. Furthermore, calcium insufficiency escalated the level of isovaleric acid and modified the metabolic profiles. MK-7 supplementation significantly increased the cortical thickness, cortical bone area, and the calcium content of the femur. Apart from improving bone calcium deposition and diminishing bone resorption, the mechanisms underlying the beneficial effects of MK on bone quality also involve the modulation of the host's metabolic pathways and the composition of gut microbiota. The gut-bone axis holds promise as an efficacious target for ameliorating calcium deficiency in children's bone quality, and MK-7 is a promising dietary supplement from this perspective.

Vitamin D intake and bone mineral density in Korean adults: analysis of the 2009-2011 Korea National Health and Nutrition Examination Survey

BACKGROUND/OBJECTIVES

The prevalence of vitamin D deficiency in Koreans is quite high; however, until recently, Korean National Health and Nutrition Survey (KNHANES) had not analyzed the vitamin D intake among Koreans. Additionally, the Korean Dietary Reference Intake for vitamin D was established based on insufficient evidence. Therefore, we investigated vitamin D intake and its relationship with bone mineral density (BMD) in Korean adults using the combined data from the 2009-2011 KNHANES.

MATERIALS AND METHODS

This study was conducted in 11,949 healthy adults. Vitamin D intake was assessed using a 24-h recall method, and the BMD was measured using dual-energy X-ray absorptiometry.

RESULTS

The prevalence of vitamin D deficiency (< 20 ng/mL) was 64% in men and 77% in women. In women aged ≥ 50 yrs and men aged < 50 yrs, there was a significant positive correlation between vitamin D intake and serum 25-hydroxyvitamin D level after sun exposure adjustment. The BMD of postmenopausal women aged ≥ 50 yrs with a vitamin D intake of 5 µg/day or more was significantly higher than that of women with intake less than 5 µg/day. After adjusting for age, energy, and calcium intake, the vitamin D intake of the osteoporotic group was significantly lower than that of the osteopenia group in women.

CONCLUSIONS

Since the relationship between vitamin D intake and BMD was observed in women aged ≥ 50 yrs, further research is needed to clarify these findings using cohort or randomized controlled trials.

Calcium status assessment at the population level: Candidate approaches and challenges

Inadequate dietary calcium intake is a global public health problem that disproportionately affects low- and middle-income countries. However, the calcium status of a population is challenging to measure, and there are no standard methods to identify high-risk communities even in settings with an elevated prevalence of a disease caused or exacerbated by low calcium intake (e.g., rickets). The calcium status of a population depends on numerous factors, including intake of calcium-rich foods; the bioavailability of the types of calcium consumed in foods and supplements; and population characteristics, including age, sex, vitamin D status, and genetic attributes that influence calcium retention and absorption. The aim of this narrative review was to assess candidate indicators of population-level calcium status based on a range of biomarkers and measurement methods, including dietary assessment, calcium balance studies, hormonal factors related to calcium, and health outcomes associated with low calcium status. Several promising approaches were identified, but there was insufficient evidence of the suitability of any single indicator to assess population calcium status. Further research is required to develop and validate specific indicators of calcium status that could be derived from the analysis of data or samples that are feasibly collected in population-based surveys.

Calcium deficiency worldwide: prevalence of inadequate intakes and associated health outcomes

Dietary calcium deficiency is considered to be widespread globally, with published estimates suggesting that approximately half of the world's population has inadequate access to dietary calcium. Calcium is essential for bone health, but inadequate intakes have also been linked to other health outcomes, including pregnancy complications, cancers, and cardiovascular disease. Populations in low- and middle-income countries (LMICs) are at greatest risk of low calcium intakes, although many individuals in high-income countries (HICs) also do not meet recommendations. Paradoxically, many LMICs with lower calcium intakes show lower rates of osteoporotic fracture as compared with HICs, though data are sparse. Calcium intake recommendations vary across agencies and may need to be customized based on other dietary factors, health-related behaviors, or the risk of calcium-related health outcomes. The lack of standard methods to assess the calcium status of an individual or population has challenged efforts to estimate the prevalence of calcium deficiency and the global burden of related adverse health consequences. This paper aims to consolidate available evidence related to the global prevalence of inadequate calcium intakes and associated health outcomes, with the goal of providing a foundation for developing policies and population-level interventions to safely improve calcium intake and status where necessary.

Case Report: Acute Kidney Injury Due to Chronic Milk-Alkali Syndrome in a Patient With Colon Cancer

BACKGROUND

Common causes of hypercalcemia include primary hyperparathyroidism and paraneoplastic syndrome of malignancy. Because of this, physicians can easily miss extrinsic causes of hypercalcemia such as milk-alkali syndrome in patients with cancer. We successfully treated a case of acute kidney injury due to severe hypercalcemia caused by milk-alkali syndrome due to long-term milk drinking in a patient with colon cancer.

CASE DESCRIPTION

A 62-year-old man was referred to nephrology for hypercalcemia and azotemia that was found during preoperative evaluation for colon cancer surgery. The patient had experienced several months of dizziness and anorexia. We started hemodialysis because hypercalcemia and azotemia were not improved despite large amounts of hydration and diuretics. We suspected paraneoplastic syndrome because of concomitant colon cancer and low intact parathyroid hormone (PTH). Renal microcalcifications were observed on ultrasonography. Metastatic calcifications of the lung and stomach were present, but no malignant metastasis appeared on bone scans. There was no evidence of metastatic malignant lesions on chest or abdominal enhanced computed tomography. PTH-related peptide was not detected. Thus, other causes of hypercalcemia beyond malignancy were considered. On history-taking, the patient reported consuming 1,000 to 1,200 mL of milk daily for the prior 3 months. Hypercalcemia was due to chronic milk-alkali syndrome. We advised withdrawal of milk and nutritional pills. Hemodialysis was stopped after 2 weeks since azotemia and hypercalcemia were resolving. Acute kidney injury was improved, and mild hypercalcemia remained when he underwent hemicolectomy after 1 month. Thereafter, serum calcium and creatinine remained normal at discharge and follow-up for 1 year in the outpatient clinic. However, lung calcifications still remained on bone scan after 1 year.

CONCLUSIONS

Chronic milk-alkali syndrome is a rare condition resulting from excessive calcium and alkali intake through various routes, like milk, nutritional supplements, and medicines for osteoporosis. Therefore, early management for hypercalcemia should include precise history taking including diet, previous diagnoses, and current medications.

Perspectives on the systematic review for the 2020 Dietary Reference Intakes for Koreans for calcium

An accurate assessment of the recommended calcium (Ca) intake may contribute to reducing the risk of fractures and chronic diseases, ultimately improving quality of life. This review was performed to summarize key findings of Ca studies, investigate the effect of Ca intake on health outcomes, and determine the adequacy of evidence to revise the 2015 Dietary Reference Intakes for Koreans (KDRIs) for Ca in 2020. Databases were searched for intervention studies that assessed health outcomes by providing Ca in diets or as supplements. The framework of the systematic review comprised conducting literature searches, data extraction, quality assessment of the literature, and summarizing key findings relevant to set the Estimated Average Requirement (EAR) and Tolerable Upper Intake Level (UL) for Ca for the 2020 KDRI. The final search was performed in June 2019. A total of 13,309 studies were identified through databases and manual search. Sixtyfive studies were included in the final quality assessment and were summarized according to health indicators. As bone health was used as an indicator of the EAR for Ca, literature reports on bone health were further categorized by the life-cycle stage of the participants. This systematic review did not find new evidence that could be applied to the general Korean adult population, including postmenopausal women, for defining a new EAR for Ca in the 2020 KDRIs. Evidence in most of the reviewed literature was considered weak; however, some evidence was found that could improve the criteria on how the EAR for Ca was determined in children and adolescents. A review of the literature for the 2020 KDRIs for Ca did not find strong evidence in order to change the recommended values of the 2015 KDRIs. More clinical interventions are required among Koreans to strengthen the body of evidence to warrant the revision of the KDRIs.

Differences in Fat-Free Mass According to Serum Vitamin D Level and Calcium Intake: Korea National Health and Nutrition Examination Survey 2008-2011

We analyzed the differences in fat-free mass (FFM) according to serum vitamin D level (VitD) and daily calcium intake (Ca) in 14,444 adults aged over 19 years. We used data from the 4th and 5th Korea National Health and Nutrition Examination Surveys (2008–2011). FFM was measured using dual-energy X-ray absorptiometry. VitD was classified as insufficient or sufficient (cutoff: 20 ng/mL). Ca was classified as unsatisfactory or satisfactory (recommended daily intake: 700 mg). In men, the FFM of group 2 (VitD ≥ 20 ng/mL; Ca < 700 mg), group 3 (VitD < 20 ng/mL; Ca ≥ 700 mg) and group 4 (VitD ≥ 20 ng/mL; Ca ≥ 700 mg) was 0.50 kg (95% confidence interval (CI), 0.084–0.92), 0.78 kg (95% CI, 0.26–1.29) and 1.58 kg (95% CI, 0.95–2.21) higher than that of group 1 (VitD < 20 ng/mL; Ca < 700 mg), respectively. In women, a 1 ng/mL increase in VitD was associated with a 0.023 kg increase in FFM (95% CI, 0.003–0.043) and a 1 g increase in Ca was associated with a 0.62 kg increase in FFM (95% CI, 0.067–1.16). High VitD and Ca were associated with a high FFM.

Relationship between Serum Nutritional Factors and Bone Mineral Density: A Mendelian Randomization Study

PURPOSE

Multiple risk factors have been implicated in the development of osteoporosis. This study examined potential associations between serum nutritional factors and bone mineral density (BMD).

METHODS

Six nutritional factors were selected as exposures. Outcomes included total body BMD (n = 66 945); BMD at the forearm (FA), femoral neck (FN) and lumbar spine (LS) (n = 8143, n = 32 735, and n = 28 498, respectively); estimated heel BMD (HL eBMD) (n = 394 929); and HL eBMD stratified by sex (n = 206 496). A 2-sample Mendelian randomization approach was adopted to estimate the association between serum nutritional factors and BMD. The threshold for adjusted P value was 1.39 × 10-3.

RESULTS

Serum calcium levels were inversely associated with LS BMD (effect = -0.55; 95% CI, -0.86 to -0.24; P = 0.001), whereas serum selenium levels were positively correlated with HL eBMD (effect = 0.22; 95% CI, 0.10 to 0.33; P = 1.70 × 10-4). Regarding nominal significance, there was a positive association between serum selenium levels and FA BMD. Nominally significant results were also obtained for serum retinol as well as vitamin E levels and HL eBMD. Moreover, sex-specific effects of serum retinol and vitamin E levels on BMD were observed in men.

CONCLUSION

Serum calcium and selenium levels influence BMD at specific skeletal sites. This implies that these nutritional factors play crucial roles in bone metabolism.

Blunted PTH response to vitamin D insufficiency/deficiency and colorectal neoplasia risk

BACKGROUND & AIMS

In contrast to many observational studies, large-scale randomized trials do not support the protective role of vitamin D for the prevention of colorectal neoplasia. However, in previous studies, individuals with blunted parathyroid hormone (PTH) response to vitamin D insufficiency/deficiency (BPRVID), were not differentiated from those with high PTH response to vitamin D insufficiency/deficiency (HPRVID). Individuals with BPRVID are responsive to magnesium treatment, particularly treatment of magnesium plus vitamin D while those with HPRVID are responsive to vitamin D treatment. We prospectively compared these two distinct groups (i.e. BPRVID and HPRVID) for risk of incident adenoma, metachronous adenoma, and incident colorectal cancer (CRC) METHODS: Three nested case-control studies in the Prostate, Lung, Colorectal and Ovarian Cancer (PLCO) Screening Trial.

RESULTS

We found optimal 25(OH)D levels were associated with a significantly reduced risk of CRC, primarily among women. The associations between 25(OH)D and CRC risk significantly differed by PTH levels, particularly among women. Compared to individuals with optimal levels for both 25(OH)D and PTH, all others were at an elevated risk of incident CRC, primarily in women. We found those with BPRVID had 2.56-fold significantly increased risk of CRC compared to 1.65-fold non-significantly increased risk for those with HPRVID. Among women, we observed those with BPRVID had 4.79-6.25-fold significantly increased risks of incident CRC and adenoma whereas those with HPRVID had 3.65-fold significantly increased risk of CRC.

CONCLUSIONS

Individuals with BPRVID are at higher risks of incident adenoma and CRC compared to those with HPRVID, particularly among women.

Data mining: Biological and temporal factors associated with blood parathyroid hormone, vitamin D, and calcium concentrations in the Southwestern Chinese population

BACKGROUND

Parathyroid hormone (PTH) and vitamin D plays a major role in calcium (Ca) homeostasis and bone turnover. The purpose of this study was to assess which factors (sex, age, time of blood sampling, season of the year, temperature and sunshine hours (SHH)) had the greatest impact on plasma PTH, 25-OH-VitD, and Ca levels, and then whether these effects were clinically acceptable in a large number of Southwestern Chinese subjects.

METHOD

The data was from West China Hospital Health Examination Center, Sichuan University from April 1, 2018 to June 30, 2019. A total of 18,664 physical examination subjects were included. PTH and 25-OH-VitD were measured by a Roche Cobas e 601, and Ca was measured by a Roche Cobas 8000. Linear regression models were used to assess correlations between PTH, 25-OH-VitD, Ca and the above factors.

RESULTS

The concentrations of serum PTH in females were significantly higher than those in males, while the 25-OH-VitD and Ca were opposite. The concentration of PTH in data collection decreased in summer and increased in spring. The concentration of 25-OH-VitD decreases in spring and increases in autumn. PTH concentrations were negatively correlated with last month temperature and SHH, while 25-OH-VitD were opposite. Linear regression showed that season may be the main factor affecting serum PTH and 25-OH-VitD levels, and these effects were not clinically acceptable.

CONCLUSION

In order to avoid influencing clinicians' investigation of suspected hyperparathyroidism and hypovitaminosis, reference intervals for PTH, 25-OH-VitD, and Ca should be established, taking into account sex, age and the season.

Longitudinal Observation of Muscle Mass over 10 Years According to Serum Calcium Levels and Calcium Intake among Korean Adults Aged 50 and Older: The Korean Genome and Epidemiology Study

The aim of this study was to investigate the longitudinal change in muscle mass over 10 years according to serum calcium levels and calcium intake. A total of 1497 men and 1845 women aged 50 years and older were included. Significant muscle loss (SML) was defined as a 5% or greater loss from baseline, while time-dependent development of SML was assessed according to quartiles for corrected calcium level and daily calcium intake using Cox regression models. The incidence of SML was 6.7 and 7.7 per 100-person-years among men and women, respectively. Groups with the lowest corrected calcium levels had more prominent SML than those with higher calcium levels, regardless of sex. The relationship between SML and calcium intake was significant only among women. The hazard ratio for SML per 1 mmol/L increase in corrected calcium level was 0.236 and 0.237 for men and women, respectively. In conclusion, low serum calcium levels may predict SML among adults aged ≥ 50 years, while low calcium intake may be a predictor for muscle loss among women. Therefore, encouraging dietary calcium intake among middle-aged and older adults for preservation of muscle mass should be considered.

LPS-induced inflammation disorders bone modeling and remodeling by inhibiting angiogenesis and disordering osteogenesis in chickens

Inflammation plays a negative role in the growth and development of bone. However, the underlining mechanisms of inflammation caused abnormal bone development and even bone disease are still poorly understood, especially in chickens. In this study, we explored the influence of inflammation on bone formation in broilers for the first time by using lipopolysaccharide (LPS) to establish systemic inflammatory models in chickens with tibia as the research object. The measurements of production and tibial parameters showed an inefficient production performance and lower growth rate in LPS group. We also found a large amount of platelets, inflammatory cells in chickens' blood and higher levels of inflammatory factors in serum after LPS injection, meanwhile, increase in thrombus, chondrocyte nucleolysis, and osteoclasts and a reduction in blood vessels were observed in growth plate through histological observation. The qPCR analysis showed that the mRNA expression levels of NF-κB, TLR4, TF, TPO, and its receptor C-MPL enhanced, while VEGFA was inhibited in LPS group. In addition, in OPG/RANKL system, OPG was decreased while RANKL enhanced. It was also observed that the mRNA levels of MMP-9 and its inducing factor CD147 enhanced in LPS group. The western blot results were basically in consistent with mRNA test. Thus, we infer that inflammation can inhibit bone modeling and remodeling by affecting angiogenesis and osteogenesis, and result in negative effect on bone formation furtherly.

Seasonal variation and correlation analysis of vitamin D and parathyroid hormone in Hangzhou, Southeast China

This study aimed to describe the 25‐hydroxyvitamin D (25(OH)D) and parathyroid hormone (PTH) status of Southeast Chinese individuals influenced by season. The secondary aim was to determine the cutoff for sufficient 25(OH)D in a four‐season region. From January 2011 to June 2014, a total of 17 646 individuals were evaluated in our study. The serum levels of PTH were detected simultaneously in 5579 cases. A total of 25(OH)D and intact PTH were measured by the electrochemiluminescent immunoassay. The distribution of the concentration, prevalence and seasonal variability of 25(OH)D and PTH were studied. The mean 25(OH)D concentration in our study was 43.00(30.40) nmol/L. The prevalence of insufficiency (25(OH)D < 50 nmol/L) was 62.87% and that of deficiency (<30 nmol/L) was 28.54%. Mean serum 25(OH)D levels revealed a limited sinusoidal profile throughout the year and were significantly higher in Autumn. On the other hand, PTH levels showed an opposite response to seasonal effects relative to 25(OH)D. Age, BMI and daylight were not significantly correlated with 25(OH)D and serum PTH reached a plateau at higher values of serum 25(OH)D of 42.86 nmol/L. This study demonstrated that Vitamin D insufficiency is highly prevalent in Southeast China. The concentration of 25(OH)D in the male group was generally higher than that in the female group. Seasonal variation was an important aspect of 25(OH)D and PTH concentration. This study revealed that the optimal serum threshold of 25(OH)D for bone health should be between 40 and 50 nmol/L for Southeast Chinese individuals.

Association of Genetic Variants Related to Serum Calcium Levels with Reduced Bone Mineral Density

CONTEXT

The role of serum calcium in bone metabolism is unknown, even though calcium/vitamin D supplementations have been widely used and are expected to improve bone health. We aim to determine the independent role of serum calcium in bone mineral density (BMD).

DESIGN AND SETTING

Two epidemiological analyses with 5478 and 5556 participants from the National Health and Nutrition Examination Survey (NHANES) 2003 to 2006 and the Hong Kong Osteoporosis Study (HKOS) to evaluate the cross-sectional association of serum calcium with BMD. Two-sample Mendelian randomization (MR) studies using genetic variations as instrumental variables to infer causality. Summary statistics of genome-wide association study of serum calcium (N = 39 400) and lifelong whole-body BMD (N = 66 628) were used.

MAIN OUTCOME MEASURE

BMD measured by dual-energy X-ray absorptiometry.

RESULTS

In NHANES 2003-6 and HKOS, each standard deviation (SD) increase in serum calcium was significantly associated with 0.036-0.092 SD decrease in BMD at various sites (all P < .05). In multivariable inverse-variance weighted MR analysis, genetic predisposition to higher serum calcium level was inversely associated with whole-body BMD after adjustment for serum parathyroid hormone, vitamin D, and phosphate (-0.431 SD per SD increase in serum calcium; 95% CI: -0.773 to -0.089, P = .014). Similar estimates were obtained in sensitivity analyses.

CONCLUSIONS

Our study reveals that genetic predisposition to higher serum calcium level per se may have a negative impact on bone metabolism. Whether increased serum calcium caused by calcium/vitamin D supplementations would have the same negative effect on bone remains unknown, which warrants further investigation. In addition to other adverse clinical outcomes, careful use of high-dose supplementations is required.

Parathormone Levels in a Middle-Eastern Healthy Population Using 2nd and 3rd Generation PTH Assays

BACKGROUND

The purpose of the current study is to determine PTH reference values in vitamin-D-replete Lebanese adults using 2^nd and 3^rd generation PTH assays and to look at the factors that affect PTH variations.

METHODS

Fasting PTH was measured using 2^nd and 3^rd generation Diasorin PTH assays in 339 vitamin-D-replete healthy subjects aged 18 to 63 years (230 men and 109 women) who have normal calcium levels and an eGFR ≥60 ml/mn. 25-OH vitamin D (25(OH)D) was measured using the Diasorin assay.

RESULTS

For the 2^nd PTH generation, median (IQR) levels were 48.9 (34.9-66.0) pg/ml, and its 2.5^th-97.5^th percentile values were 19.7-110.5 pg/ml for 25(OH)D values between 20 and 30 ng/ml, and 19.7-110.7 pg/ml for 25(OH)D values ≥30 ng/ml. For the 3^rd PTH generation, the median (IQR) values were 23.9 (17.7-30.5) pg/ml, and its 2.5^th-97.5^th percentile values were, respectively, 9.2 and 50.2 pg/ml for 25(OH)D values between 20 and 30 ng/ml, and 8.4 and 45.4 pg/ml for 25(OH)D values ≥30 ng/ml. The median (IQR) serum 25(OH)D levels were 27.5 (23.8-32.7) ng/ml. 2^nd and 3^rd generation PTH values are strongly correlated (r = 0.96, p < 0.0001), but poorly concordant (Lin's concordance coefficient 0.365, 95% CI: 0.328-0.401) with observations beyond the 95% Bland-Altman limits of agreement. 2^nd and 3^rd generation PTH levels did not differ according to gender and were significantly correlated with age but not with 25(OH)D and serum calcium levels.

CONCLUSION

Lebanese adult healthy subjects have higher 2^nd and 3^rd generation PTH levels compared with the reference range provided by the manufacturer. The reference range was not influenced by changing the 25(OH)D cutoff. The clinical significance of the higher PTH levels in our population should be investigated.

Metabolic characteristics of subjects with spine-femur bone mineral density discordances: the Korean National Health and Nutrition Examination Survey (KNHANES 2008-2011)

The diagnosis of osteoporosis is determined based on the lowest bone mineral density (BMD) T-score at the lumbar spine (LS) and hip. However, there are occasional marked discordances between the T-score of LS and femur neck (FN). We aimed to examine the prevalence and characteristics of individuals with spine-femur BMD discordance using a nationwide survey. A total of 3233 men aged ≥ 50 years and 2915 postmenopausal women were included from the Korean National Health and Nutrition Examination Surveys (2008-2011). The spine-femur discordance was defined as a difference of ≥ 1.5 SD between LS and FN BMD. Subjects were divided into three groups: low LS (LS < FN), low FN (LS > FN), and no discordance. Four-hundred and seventeen men (12.9%) and two hundred and ninety women (10%) exhibited spine-femur BMD discordance. The prevalence of hypertension and diabetes was higher in men and women with low FN BMD than in any other group. Fasting plasma glucose and homeostasis model assessment of insulin resistance was the highest in subjects with low FN BMD among the three groups. Low FN BMD revealed higher serum parathyroid hormone and lower 25-hydroxyvitamin D3 levels compared to any other group in women, but this was not observed in men. Osteoporosis was prevalent in subjects with discordance in both genders, particularly, in those with low LS BMD (31.6% in men and 63.5% in women). Given the high prevalence of spine-femur BMD discordance, low FN BMD may be associated with vitamin D deficiency and insulin resistance, but low LS BMD may present severe osteoporosis.

Vitamin D Status and Indices of Mineral Homeostasis in the Population: Differences Between 25-Hydroxyvitamin D and 1,25-Dihydroxyvitamin D

Opinions are conflicting about the epidemiology of vitamin D deficiency. This population-based study investigated cross-sectionally the associations of 25-hydroxyvitamin D (calcidiol) and 1,25-dihydroxyvitamin D (calcitriol) with indices of mineral homeostasis. Study cohort consisted of 979 persons of the Moli-Sani study, both sexes, ages ≥35 years. Data collection included serum calcidiol by different assays, serum calcitriol, serum parathyroid hormone, serum and urine calcium, and phosphorus. Prevalence of mild-to-moderate calcidiol deficiency (10–19 ng/mL) was 36.4% and did not associate with hypocalcemia or hyperparathyroidism. Prevalence of severe calcidiol deficiency (<10 ng/mL) was 16.8% and associated with hyperparathyroidism only (odds ratio = 8.81, 95% confidence interval = 2.4/32.9). Prevalence of calcitriol deficiency (<18 pg/mL) was 3.1% and associated with hypocalcemia (29.1, 7.4/114.5) but not hyperparathyroidism. In ANOVA along concentration strata, lower calcidiol associated with higher parathyroid hormone only (p < 0.001). Lower calcitriol associated with lower serum and urine calcium (p < 0.001) but not with parathyroid hormone. Calcidiol findings were consistent with different calcidiol assays. In the population, mild-to-moderate calcidiol deficiency did not associate with abnormal mineral homeostasis. Severe calcidiol deficiency and calcitriol deficiency associated with different disorders: lower calcidiol associated with hyperparathyroidism whereas lower calcitriol associated with hypocalcemia and low urine calcium.

Supplemental calcium intake in the aging individual: implications on skeletal and cardiovascular health

Adequate calcium intake during childhood is necessary to achieve optimal peak bone mass and this has the potential by increasing bone reserves, to modulate the rate of age-associated bone loss. However, data regarding the efficacy of calcium obtained either through the diet or in the form of medicinal supplementation, for prevention of bone loss and osteoporotic fractures in the elderly is conflicting. Calcium alone is unlikely to be of benefit for this purpose though the co-administration of calcium and vitamin D may have modest fracture risk benefits. Supplemental calcium with or without vitamin D has recently come into the spotlight after the publication of the findings from a controversial randomized controlled trial that associated calcium supplementation with an increased risk of myocardial infarction. Since then, multiple studies have explored this potential link. The data remains conflicting and the potential mechanistic link if any exists, remains elusive. This review examines the relationship between supplemental calcium intake and skeletal and cardiovascular health in the aging individual through an appraisal of studies done on the subject in the last three decades. It also briefly details some of the studies evaluating fractional absorption of calcium in the elderly and the rationale behind the current recommended dietary allowances of calcium.

Trends of Food Supply and Nutrient Intake in South Korea Over the Past 30 Years

Purpose: This study was conducted to investigate food supply and consumption trends in South Korea over the past 30 years (1980 to 2010). Methods: We used time series data on Food Balance Sheets of Korea and the National Health and Nutrition Survey from Korea Statistics. Regression analysis was performed for trends of food supply and demand, and t-test for the gender difference in nutrient intake. Results: The annual supply of cereals, rice and starch roots per person has decreased, while that of meat, fish and shellfish, eggs, milk, and fats and oils has increased (p < 0.05), respectively. These changes effect on nutrient intake: rice consumption has declined to one-third of total energy intake, however, the energy intake from lipid sources has increased up to 20% in the 2000s.The nutrient intake levels are mostly sufficient to meet the recommended intake, but calcium intake is below the recommended level and sodium is three times above the recommended level. These problems are found in both genders, and males take in more calories and sodium than females (p < 0.05). Conclusion: These changes in food consumption and supply resulted in lowering both quantities based food self-sufficiency rate and self-sufficiency of nutrition supply. It is therefore suggested that the supply of agricultural products should be stable and quality competitiveness in supply should be improved. Also, measures and strategies in promoting rice consumption are required, such as promoting healthy diet via nutrition education and disseminating healthy traditional Korean food.

Bone Microstructure in Response to Vitamin D3 Supplementation: A Randomized Placebo-Controlled Trial

Vitamin D supplementation is often used in the prevention and treatment of osteoporosis, but the role of vitamin D has lately been questioned. We aimed to investigate the effect of 3 months of daily vitamin D3 supplementation (70 µg [2800 IU] vs. placebo) initiated in winter months on bone health. This study is a double-blinded placebo-controlled randomized trial. Bone health was assessed by bone turnover markers, DXA, HRpQCT, and QCT scans. The participants were 81 healthy postmenopausal women with low 25(OH)D (< 50 nmol/l) and high PTH levels (> 6.9 pmol/l) at screening. Vitamin D3 supplementation significantly increased levels of 25(OH)D and 1,25(OH)₂D by 59 nmol/l and 19 pmol/l, respectively, whereas PTH was reduced by 0.7 pmol/l (all p < 0.0001). Compared with placebo, vitamin D3 did not affect bone turnover markers, aBMD by DXA or trabecular bone score. Vitamin D3 increased trabecular vBMD (QCT scans) in the trochanter region (0.4 vs. - 0.7 g/cm³) and the femoral neck (2.1 vs. - 1.8 g/cm³) p_all < 0.05. HRpQCT scans of the distal tibia showed reduced trabecular number (- 0.03 vs. 0.05 mm^-1) and increased trabecular thickness (0.001 vs. - 0.005 mm), as well as an improved estimated bone strength as assessed by failure load (0.1 vs. - 0.1 kN), and stiffness (2.3 vs. - 3.1 kN/mm p_all ≤ 0.01). Changes in 25(OH)D correlated significantly with changes in trabecular thickness, stiffness, and failure load. Three months of vitamin D3 supplementation improved bone strength and trabecular thickness in tibia, vBMD in the trochanter and femoral neck, but did not affect aBMD.

Interactions between Vitamin D Status, Calcium Intake and Parathyroid Hormone Concentrations in Healthy White-Skinned Pregnant Women at Northern Latitude

Adverse effects of low vitamin D status and calcium intakes in pregnancy may be mediated through functional effects on the calcium metabolic system. Little explored in pregnancy, we aimed to examine the relative importance of serum 25-hydroxyvitamin D (25(OH)D) and calcium intake on parathyroid hormone (PTH) concentrations in healthy white-skinned pregnant women. This cross-sectional analysis included 142 participants (14 ± 2 weeks' gestation) at baseline of a vitamin D intervention trial at 51.9 °N. Serum 25(OH)D, PTH, and albumin-corrected calcium were quantified biochemically. Total vitamin D and calcium intakes (diet and supplements) were estimated using a validated food frequency questionnaire. The mean ± SD vitamin D intake was 10.7 ± 5.2 μg/day. With a mean ± SD serum 25(OH)D of 54.9 ± 22.6 nmol/L, 44% of women were <50 nmol/L and 13% <30 nmol/L. Calcium intakes (mean ± SD) were 1182 ± 488 mg/day and 23% of participants consumed <800 mg/day. The mean ± SD serum albumin-adjusted calcium was 2.2 ± 0.1 mmol/L and geometric mean (95% CI) PTH was 9.2 (8.4, 10.2) pg/mL. PTH was inversely correlated with serum 25(OH)D (r = -0.311, p < 0.001), but not with calcium intake or serum calcium (r = -0.087 and 0.057, respectively, both p > 0.05). Analysis of variance showed that while serum 25(OH)D (dichotomised at 50 nmol/L) had a significant effect on PTH (p = 0.025), calcium intake (<800, 800⁻1000, ≥1000 mg/day) had no effect (p = 0.822). There was no 25(OH)D-calcium intake interaction effect on PTH (p = 0.941). In this group of white-skinned women with largely sufficient calcium intakes, serum 25(OH)D was important for maintaining normal PTH concentration.

Assessment of the effects of switching oral bisphosphonates to denosumab or daily teriparatide in patients with rheumatoid arthritis

The aim of this observational, non-randomized study was to clarify the unknown effects of switching oral bisphosphonates (BPs) to denosumab (DMAb) or daily teriparatide (TPTD) in patients with rheumatoid arthritis (RA). The characteristics of the 194 female patients included in the study were 183 postmenopausal, age 65.9 years, lumbar spine (LS) T score -1.8, femoral neck (FN) T score -2.3, dose and rate of taking oral prednisolone (3.6 mg/day) 75.8%, and prior BP treatment duration 40.0 months. The patients were allocated to (1) the BP-continue group (n = 80), (2) the switch-to-DMAb group (n = 74), or (3) the switch-to-TPTD group (n = 40). After 18 months, the increase in bone mineral density (BMD) was significantly greater in the switch-to-DMAb group than in the BP-continue group (LS 5.2 vs 2.3%, P < 0.01; FN 3.8 vs 0.0%, P < 0.01) and in the switch-to-TPTD group than in the BP-continue group (LS 9.0 vs 2.3%, P < 0.001; FN 4.9 vs 0.0%, P < 0.01). Moreover, the switch-to-TPTD group showed a higher LS BMD (P < 0.05) and trabecular bone score (TBS) (2.1 vs -0.7%; P < 0.05) increase than the switch-to-DMAb group. Clinical fracture incidence during this period was 8.8% in the BP-continue group, 4.1% in the switch-to-DMAb group, and 2.5% in the switch-to-TPTD group. Both the switch-to-DMAb group and the switch-to-TPTD group showed significant increases in LS and FN BMD, and the switch-to-TPTD group showed a higher increase in TBS compared to the BP-continue group at 18 months. Switching BPs to DMAb or TPTD in female RA may provide some useful osteoporosis treatment options.

Role and regulation of growth plate vascularization during coupling with osteogenesis in tibial dyschondroplasia of chickens

Tibial dyschondroplasia (TD) is the most-prevalent leg disorder in fast-growing chickens; it is intractable and characterized by abnormal endochondral bone formation of proximal tibial growth-plates (TGPs). Previous studies have shown that bone is a highly vascularized tissue dependent on the coordinated coupling between angiogenesis and osteogenesis, but the underlying mechanisms of bone formation and bone remodeling are poorly defined in TD chickens. Here, we observed that inhibition of vasculogenesis and angiogenesis remarkably impaired vascular invasion in the hypertrophic chondrocyte zone of the TGPs, resulting in the massive death of chondrocytes due to a shortage of blood vessels and nutrients. Moreover, the balance of the OPG (osteoprotegerin)/RANKL (receptor activator of nuclear factor-kB ligand) system is also severely disrupted during the osteogenesis process while coupling with angiogenesis, both of which eventually lead to abnormal endochondral bone formation in TD chickens. Thus, the process of vascular formation in endochondral bone appears to initiate the pathological changes in TD, and improvement of this process during coupling with osteogenesis may be a potential therapeutic approach to treat this intractable disease.

The increase in bone mineral density by bisphosphonate with active vitamin D analog is associated with the serum calcium level within the reference interval in postmenopausal osteoporosis

OBJECTIVES

To examine the factors associated with increase in lumbar spine bone mineral density (LS-BMD) by bisphosphonates (BPs) with active vitamin D analog (aVD).

METHODS

Two independent postmenopausal osteoporotic patients treated by BPs with aVD for 24 months (Study 1: n = 93, Study 2: n = 99) were retrospectively analyzed.

RESULTS

In Study 1, LS-BMD of the patients significantly increased for 24 m (5.4%, p < .001). A multiple regression analysis among baseline characteristics revealed that serum calcium (sCa: 8.5-10.5 mg/dL) was associated with an increased LS-BMD by treatment (r²: 0.088, p = .02). While average sCa of the patients was 9.2 mg/dL before treatment, it increased time-dependently to 9.6 mg/dL for 24 m by treatment. As each patient had their LS-BMD five times during the study, there were four instances of %LS-BMD in each patient, resulting in 372 instances of %LS-BMD in Study 1. The smallest Akaike's information criterion value for the most appropriate cut-off levels of sCa for %LS-BMD by treatment every 6 m was 9.3 mg/dL. The %LS-BMD by treatment for 6 m during 24 m period in patients with sCa ≥9.3 mg/dL (1.5%) was significantly higher than that in patients with sCa <9.3 mg/dL (0.8%, p = .038). The results of Study 2 were similar to those of Study 1, confirming the phenomena observed.

CONCLUSION

sCa was associated with an increased LS-BMD by BPs with aVD.

Education and exercise program improves osteoporosis knowledge and changes calcium and vitamin D dietary intake in community dwelling elderly

BACKGROUND

Several educational intervention programs have been designed and developed to improve osteoporosis diagnosis and treatment. However, most of the prior studies focused on how educational intervention programs affected diagnosis and treatment of condition of osteoporosis. The purpose of this prospective and educational intervention study was to evaluate the changes in osteoporosis knowledge, osteoporosis self-efficacy, fall self-efficacy, physical exercise and changes in dietary pattern of calcium and vitamin D intake after osteoporosis education.

METHODS

From November 1, 2015 to August 31, 2016, 271 eligible candidates (who were over 50 years old and from 23 different community centers) were recruited through an announcement made by the public office, by two health care providers. The intervention involved an individualized education program to allow for differences in antecedent educational levels regarding several aspects of osteoporosis, including osteoporosis knowledge, osteoporosis self-efficacy, awareness of self-efficacy risk factors relating to an accidental fall and nutritional education (including the importance of sufficient calcium and vitamin D intake). The researchers revisited the community centers three months after the initial visit.

RESULTS

Of the 271 potential participants, 199 (73.4%; 43 men and 156 women) completed the education program and the second questionnaire. After education intervention, parameters including osteoporosis knowledge, osteoporosis self-efficacy and fall self-efficacy were improved (P < 0.0001). After education regarding percentage of calcium and vitamin D intake below recommended cut-offs, inadequate dietary calcium and vitamin D intake were decreased (P < 0.0001) from 89.4% (178/199) and 84.4% (168/199) to 79.9% (159/199) and 65.8% (131/199), respectively, at the three-month follow-up. (p = 0.038, p = 0.017).

CONCLUSIONS

This prospective intervention study demonstrated that education on osteoporosis knowledge and regular exercise programs could improve osteoporosis self- efficacy, fall self-efficacy and increase dietary calcium and vitamin D intake.

Global dietary calcium intake among adults: a systematic review

Low calcium intake may adversely affect bone health in adults. Recognizing the presence of low calcium intake is necessary to develop national strategies to optimize intake. To highlight regions where calcium intake should be improved, we systematically searched for the most representative national dietary calcium intake data in adults from the general population in all countries. We searched 13 electronic databases and requested data from domain experts. Studies were double-screened for eligibility. Data were extracted into a standard form. We developed an interactive global map, categorizing countries based on average calcium intake and summarized differences in intake based on sex, age, and socioeconomic status. Searches yielded 9780 abstracts. Across the 74 countries with data, average national dietary calcium intake ranges from 175 to 1233 mg/day. Many countries in Asia have average dietary calcium intake less than 500 mg/day. Countries in Africa and South America mostly have low calcium intake between about 400 and 700 mg/day. Only Northern European countries have national calcium intake greater than 1000 mg/day. Survey data for three quarters of available countries were not nationally representative. Average calcium intake is generally lower in women than men, but there are no clear patterns across countries regarding relative calcium intake by age, sex, or socioeconomic status. The global calcium map reveals that many countries have low average calcium intake. But recent, nationally representative data are mostly lacking. This review draws attention to regions where measures to increase calcium intake are likely to have skeletal benefits.

Association between Dietary Carotenoid Intake and Bone Mineral Density in Korean Adults Aged 30-75 Years Using Data from the Fourth and Fifth Korean National Health and Nutrition Examination Surveys (2008-2011)

Age-related bone loss is a major public health problem. This cross-sectional study examined the association between the dietary intake of carotenoids and bone mineral density (BMD). Data from 8022 subjects (3763 males and 4259 females) aged 30–75 years included in the Korean National Health and Nutrition Examination Survey (2008–2011) were analyzed. BMD was measured by dual-energy X-ray absorptiometry. Intake of carotenoids was estimated using 24-h dietary recall. In multiple linear analysis, after adjusting for covariates, lutein + zeaxanthin and β-cryptoxanthin intake was positively associated with total hip BMD in males and premenopausal women respectively, while β-carotene intake was positively correlated with femoral neck, total hip, and whole-body BMD in postmenopausal women. Postmenopausal women in the highest quintile of daily β-carotene intake, showed a lower risk of osteopenia at the lumbar spine (odds ratio (OR): 0.35, 95% CI: 0.16–0.79, P for trend = 0.009) than those in the lowest quintile, after adjusting for covariates. Daily β-cryptoxanthin intake was significantly associated with a lower risk of osteopenia at the total hip (OR per 1 mg/day increase: 0.76; 95% CI: 0.59–0.97), and lumbar spine (OR per 1 mg/day increase: 0.79; 95% CI: 0.70–0.89) in postmenopausal women. These results suggest that the dietary intake of β-carotene and β-cryptoxanthin may have a positive effect on bone health.

Low calcium and vitamin D intake in Korean women over 50 years of age

Inadequate calcium and vitamin D intake is a possible risk factor of osteoporosis. Our purposes were to estimate calcium and vitamin D intake in Korean women, and to determine associated risk factors for low calcium and vitamin D intake. This is a multicenter, hospital-based, and cross-sectional study on osteoporosis. In this study, 1516 women of 50 years or older were involved. Dietary calcium and vitamin D intake were evaluated using the self-reporting KCAT questionnaire. Average daily calcium intake was 662.8 ± 473.8 mg, and vitamin D intake 9.5 ± 10.7 μg. In multivariate analysis, older age (OR 1.02, 95 % CI 1.00-1.04, p = 0.001), and rural residence (OR 2.43, 95 % CI 1.34-4.43, p = 0.004) were significant risk factors for lower calcium intake, and older age (OR 1.03, 95 % CI 1.02-1.04, p < 0.001), and rural residence (OR 1.85, 95 % CI 1.10-3.11, p < 0.001) were significant risk factors for lower vitamin D intake. About 70 % of women aged 50 years or older had calcium and vitamin D intake below the recommended dietary intake. Older age and rural residence were significant risk factors for lower calcium and vitamin D intake in Korean women.

Association between bone mineral density, muscle strength, and vitamin D status in patients with myasthenia gravis: a cross-sectional study

Myasthenia gravis (MG) patients had low proximal hip BMD, which could be explained by reduced muscle strength, elevated bone resorption markers, vitamin D deficiency, and increased PTH levels in those with MG compared to controls.

INTRODUCTION

Muscle strength is closely correlated with bone mineral density (BMD) and vitamin D status. Here, we evaluated muscle strength, BMD, and vitamin D status in a large sample of Chinese patients with MG.

METHODS

In this cross-sectional survey, 86 patients with MG without glucocorticoid treatment and 86 healthy controls were included. Serum levels of 25-hydroxyvitamin D [25OHD], parathyroid hormone (PTH), bone turnover markers (BTMs), and BMD were measured and compared between the two groups. Grip strength and one-leg standing time (OLST) were also assessed in MG patients.

RESULTS

Low grip strength and short OLST were found in 11 (12.8%) and 12 (14.0%) MG patients, respectively. There were 3 (3.5%) MG patients with low bone mass for chronological age. Serum beta C-terminal telopeptide and PTH levels were higher (p < 0.001 and p = 0.001, respectively), and BMD at the femoral neck and trochanter were lower in MG patients (p < 0.001 and p < 0.001, respectively) compared to healthy controls. In patients with MG, grip strength was positively correlated with BMD. Serum 25OHD levels were lower in MG patients than in healthy controls (17.36 ± 6.64 vs. 22.11 ± 7.28 ng/ml, p < 0.001).

CONCLUSION

Grip strength was positively correlated with BMD in Chinese patients with MG. MG patients tended to have low proximal hip BMD, which may partially be explained by reduced muscle strength, vitamin D deficiency, increased PTH levels, and elevated bone resorption markers compared to controls.

Dietary calcium intake and rate of bone loss in men

A high Ca intake has been recommended for osteoporosis prevention; however, little research has examined the relationship between dietary Ca and bone health in men. We examined associations between dietary Ca intake, bone mineral density (BMD) and change in BMD at the total body, hip and spine over 2 years in a cohort of men (mean age 57 years, BMI 26 kg/m2) from a trial. Data from the total cohort (n 323) were used in the analysis of Ca intake and BMD at baseline, and data from the placebo group (n 99) were used in the longitudinal analysis of Ca intake and change in BMD. Parathyroid hormone (PTH) and the markers of bone turnover serum total alkaline phosphatase activity, serum C-telopeptide and serum procollagen type-1 N-terminal propeptide were measured in a subset of participants at baseline (n 150), and associations with dietary Ca at baseline were examined. Mean Ca intake was 870 mg/d. Baseline BMD was not related to dietary Ca intake at any site, before or after adjustment for covariables. Similarly, bone loss over 2 years was not related to Ca intake at any site, before or after adjustment. Dietary Ca intake was inversely correlated with PTH at baseline (r −0·19, P=0·02), but was not associated with the markers of bone turnover. BMD and rates of bone loss were unrelated to Ca intake in these men. This suggests that strategies to increase Ca intake are unlikely to impact on the prevalence of and morbidity from male osteoporosis.

The effects of switching daily teriparatide to oral bisphosphonates or denosumab in patients with primary osteoporosis

The aim of this 12-month, observational study was to compare the effects of switching daily teriparatide (TPTD) to oral bisphosphonates (BP) therapy or denosumab (DMAb) therapy in patients with primary osteoporosis. Patients [n = 78; 71 postmenopausal women and seven men; mean age 76.3 (64-94) years; mean duration of prior daily TPTD therapy 20.1 (6-24) months] were allocated to either the (1) "switch-to-BP" group [n = 36; weekly alendronate 35 mg (n = 19), weekly risedronate 17.5 mg (n = 12), monthly minodronate 50 mg (n = 5)]; or (2) "switch-to-DMAb" group (n = 42; 60 mg sc every 6 months) based on each physicians' decision. Changes in bone mineral density (BMD) and serum bone turnover markers were monitored every 6 months. No significant difference was observed in baseline clinical characteristics between the groups. After 12 months, the increase in BMD was significantly greater in the switch-to-DMAb group compared to the switch-to-BP group: lumbar spine (6.2 vs. 2.6 %; P < 0.01), total hip (4.2 vs. 1.1 %; P < 0.05), and femoral neck (3.5 vs. 1.4 %; P < 0.05). In addition, the patients in the switch-to-DMAb group showed a significant decrease compared to those in the switch-to-BP group in TRACP-5b (-55.8 vs. -32.8 %; P < 0.01) and ucOC (-85.5 vs. -65.0 %; P < 0.001), while no significant difference was observed in PINP (-67.5 vs. -62.1 %). Switching daily TPTD to DMAb significantly increased BMD and decreased bone resorption marker compared to switching to oral BP at 12 months, and thus may provide an effective sequential treatment option after daily TPTD treatment.

Recent nutritional trends of calcium and vitamin D in East Asia

Calcium intake may play an important role on bone health. The recent national nutritional survey in Japan revealed the gradual decrease in calcium intake to around 480 mg/day. In addition, the patients with low level of vitamin D become too large in proportion. The present perspective proposes to increase calcium intake in Asian population.

Association between Vitamin D Status and Risk of Peripheral Arterial Disease: The Dong-gu Study

Low levels of vitamin D have been associated with increased cardiovascular disease risk. However, few studies have evaluated the association between vitamin D status and peripheral arterial disease (PAD). We therefore aimed to investigate whether low 25-hydroxyvitamin D (25(OH)D) levels were associated with increased risk of PAD in the Korean population. This cross-sectional study was conducted among 8,960 subjects aged 50 years or older without known myocardial infarction or stroke. PAD was defined by an ankle brachial blood pressure index <0.9. Multivariate logistic regression was used to evaluate the association between serum 25(OH)D levels and risk of PAD. Of the 8,960 subjects, 3.0% had PAD and the age and sex adjusted prevalence of PAD decreased with the increasing 25(OH)D quartile. After adjusting for potential confounders and parathyroid hormones, serum 25(OH)D levels were associated with a significantly decreased risk of PAD (OR for one SD increase, 0.98; 95% CI, 0.95-1.0, P for trend=0.040). Compared with the first 25(OH)D quartile, the odds of PAD were 0.86 (95% CI, 0.62-1.21), 0.67 (95% CI, 0.46-0.97), and 0.71 (95% CI, 0.49-1.04) for the second, third, and fourth quartiles, respectively. In this cross-sectional study, we found that low serum 25(OH)D levels were associated with an increased risk of PAD, independent of traditional cardiovascular risk factors and parathyroid hormone. Our findings suggest that low vitamin D levels may contribute to PAD in the Korean population.

Inadequate Dietary Calcium and Vitamin D Intake in Patients with Osteoporotic Fracture

Background

Inadequate calcium and vitamin D intake is a possible risk factor of osteoporosis. Our purposes were to estimate calcium and vitamin D intake in women with osteoporotic fractures, to determine associated factors for low calcium and vitamin D intake, and to evaluate the effects of calcium and vitamin D intake on bone mineral density (BMD).

Methods

This is a multicenter, hospital-based, and cross-sectional study involving 277 women with osteoporotic fractures. Dietary calcium and vitamin D intake were evaluated using the Korean Calcium Assessment Tool (KCAT) self-reported questionnaire. BMD was measured by dual energy X-ray absorptiometry (DXA) in the lumbar spine and femoral neck.

Results

Average daily calcium and vitamin D intake was 503.7±274.7 mg and 7.5±12.6 µg, respectively. Patients with low calcium intake had less family history of osteoporosis and were older. There was a negative correlation between age and calcium intake (r=-0.14; P=0.019). In multivariate analysis, calcium intake showed a positive correlation with BMD of femoral neck (β=0.0005, P=0.021).

Conclusions

About 80% of patients with osteoporotic fracture had calcium and vitamin D intake below the recommended dietary intake. Low calcium intake was associated with no family history of osteoporosis and older age. Dietary calcium intake showed positive effect on BMD.

Establishment of a normal reference value of parathyroid hormone in a large healthy Chinese population and evaluation of its relation to bone turnover and bone mineral density

A normal reference value of parathyroid hormone (PTH) was established for the first time in a large sample of healthy Chinese subjects by completely excluding interference of vitamin D deficiency. A high PTH level correlated significantly with an elevated bone turnover and a reduced bone mineral density (BMD).

INTRODUCTION

The aims of this study are to establish a normal reference value for serum PTH and to evaluate the effect of parathyroid gland status on bone turnover and BMD.

METHODS

Our cross-sectional study included 1436 healthy individuals from 5 different Chinese cities. Concentrations of serum PTH, 25-hydroxyvitamin D (25OHD), procollagen I N-terminal peptide (P1NP, a bone formation marker), and carboxyl-terminal telopeptide of type I collagen (β-CTX, a bone resorption marker) were measured by electrochemiluminescence immunoassay. BMD was measured by dual-energy X-ray absorptiometry. The relation of PTH concentration to age, gender, height, and weight was examined. Reference values of PTH were established for all subjects and for subjects categorized by serum 25OHD concentrations. Correlations of PTH levels with bone turnover biomarkers and BMD were statistically analyzed.

RESULTS

Reference values of PTH were 8.84-69.95 pg/mL in all the subjects and 7.48-60.73 and 5.83-56.78 pg/mL in the subjects with serum 25OHD concentrations of ≥20 and ≥30 ng/mL, respectively. Serum PTH showed a negative linear correlation with 25OHD, and the breakpoint was 18.21 ng/mL, below which the PTH level rapidly increased. The increase in PTH levels with age showed a positive linear correlation with P1NP and β-CTX concentrations and a negative linear correlation with BMD at the lumbar spines and the femoral neck.

CONCLUSIONS

A reference value of PTH was established in a large sample of healthy Chinese subjects according to 25OHD status, gender, and age. A high PTH level correlated significantly with an elevated bone turnover and a reduced BMD.

The Level of Serum Cholesterol is Negatively Associated with Lean Body Mass in Korean non-Diabetic Cancer Patients

Due to poor nutrition and abnormal energy metabolism, cancer patients typically experience the loss of muscle mass. Although the diabetic conditions or dyslipidemia have been reported as a causal link of cancer but the consequence of such conditions in relation to gain or loss of skeletal muscle mass in cancer patients has not been well documented. The purpose of this study was to investigate the relationship of lean body mass and systemic parameters related to lipid metabolism in non-diabetic cancer patients using data from the Korean National Health and Nutrition Examination Survey (KNHANES) 2008-2011. As results the level of serum total cholesterol (total-C) was negatively associated with both total lean body mass and appendicular lean body mass in cancer patients after adjustment for sex, physical activity, energy intake and comorbidity. The associations between consumption of dietary factors (energy, carbohydrate, protein and fat) and lean body mass were disappeared after adjusting comorbidities of cancer patients. Multivariate-adjusted linear regression analysis by quartiles of serum total-C showed that higher quartile group of total-C had significantly lower percent of lean body mass than reference group in cancer patients. The data indicate that serum lipid status can be the potential estimate of loss of skeletal muscle mass in cancer patients and be referenced in nutrition care of cancer patients under the onset of cachexia or parenteral/enteral nutrition. This data need to be confirmed with large pool of subjects and should be specified by stage of cancer or the site of cancer in future studies.

Correlation between bone mineral density and serum trace elements in response to supervised aerobic training in older adults

Background

Life style and physical activity play a pivotal role in prevention and treatment of osteoporosis. The mechanism for better bone metabolism and improvement of physical disorders is not clear yet. Trace minerals such as Ca, Mn, Cu, and Zn are essential precursors for most vital biological process, especially those of bone health.

Objective

The main target of this study was evaluating the effective role of supervised aerobic exercise for 1 hour/day, 3 days/week for 12 weeks in the functions of trace elements in bone health through measuring bone mineral density (BMD), osteoporosis (T-score), bone markers, and trace element concentrations in healthy subjects aged 30–60 years with age average of 41.2±4.9.

Methods

A total of 100 healthy subjects (47 males, 53 females; age range 30–60 years) were recruited for this study. Based on dual-energy x-ray absorptiometry (DEXA) scan analysis, the participants were classified into three groups: normal (n=30), osteopenic (n=40), and osteoporotic (n=30). Following, 12 weeks of moderate aerobic exercise, bone-specific alkaline phosphatase (BAP), BMD, T-score, and trace elements such as Ca, Mn, Cu, and Zn were assessed at baseline and post-intervention.

Results

Significant improvement in serum BAP level, T-score, and BMD were observed in all participants following 12 weeks of moderate exercise. Participants with osteopenia and osteoporosis showed significant increase in serum Ca and Mn, along with decrease in serum Cu and Zn levels following 12 weeks of aerobic training. In control group, the improvements in serum trace elements and body mass index were significantly linked with the enhancement in the levels of BAP, BMD hip, and BMD spine. These results supported the preventive effects of moderate exercise in healthy subjects against osteoporosis. In both sexes, the changes in serum trace elements significantly correlated (P<0.05) with the improvement in BAP, BMD hip, BMD spine, and body mass index in all groups.

Conclusion

The observed changes in the levels of Ca, Mn, Cu, and Zn were shown to be positively correlated with improved bone mass density among control and osteoporosis subjects of both sexes. These results demonstrate that aerobic exercise of moderate intensity might protect bone and cartilage by regulation of body trace elements which are involved in the biosynthesis of bone matrix structures and inhibition of bone resorption process via a proposed anti-free radical mechanism.

Impact of Geographic Location on Vitamin D Status and Bone Mineral Density

A significant decline of serum 25-hydroxyvitamin D concentration [25(OH)D] with increasing latitude has been reported only for Caucasians. To determine the association between serum 25(OH)D and geographic location and its impact on bone mineral density (BMD) in an Asian population, a total of 17,508 subjects (8910 men and 8598 women) from the 2008–2010 Korea National Health and Nutrition Examination Survey (KNHANES) were stratified into four age groups and analyzed for 25(OH)D and BMD according to geographic location (South, 33° N–35° N; Middle, 36° N; North, 37° N–38° N). Mean 25(OH)D were 47.7 and 41.2 nmol/L; calcium intake, 564.9 & 442.3 mg/d; femoral neck BMD, 0.829 & 0.721 g/cm²; and lumbar spine BMD, 0.960 & 0.918 g/cm² for men and women, respectively. Both men and women living in the South had significantly higher 25(OH)D and femoral neck BMD for those ≥50 years old. Lumbar spine BMD was significantly higher in men ≥50 years old, and for women 10–29 & 50–69 years old living in the South. A 1 or 2 degree difference in latitude has a significant effect on serum 25(OH)D and BMD in this low vitamin D status population. Thus, consideration of geographic location for a recommendation of vitamin D intake may be necessary.

Development and Validation of Osteoporosis Risk-Assessment Model for Korean Men

PURPOSE

The aim of the present study was to develop an osteoporosis risk-assessment model to identify high-risk individuals among Korean men.

MATERIALS AND METHODS

The study used data from 1340 and 1110 men ≥50 years who participated in the 2009 and 2010 Korean National Health and Nutrition Examination Survey, respectively, for development and validation of an osteoporosis risk-assessment model. Osteoporosis was defined as T score ≤-2.5 at either the femoral neck or lumbar spine. Performance of the candidate models and the Osteoporosis Self-assessment Tool for Asian (OSTA) was compared with sensitivity, specificity, and area under the receiver operating characteristics curve (AUC). A net reclassification improvement was further calculated to compare the developed Korean Osteoporosis Risk-Assessment Model for Men (KORAM-M) with OSTA.

RESULTS

In the development dataset, the prevalence of osteoporosis was 8.1%. KORAM-M, consisting of age and body weight, had a sensitivity of 90.8%, a specificity of 42.4%, and an AUC of 0.666 with a cut-off score of -9. In the validation dataset, similar results were shown: sensitivity 87.9%, specificity 39.7%, and AUC 0.638. Additionally, risk categorization with KORAM-M showed improved reclassification over that of OSTA up to 22.8%.

CONCLUSION

KORAM-M can be simply used as a pre-screening tool to identify candidates for dual energy X-ray absorptiometry tests.

Threshold Effects of Vitamin D Status on Bone Health in Chinese Adolescents With Low Calcium Intake

CONTEXT

There is no consensus on the definition of vitamin D deficiency for bone health based on serum 25-hydroxyvitamin D (25OHD) levels.

OBJECTIVE

Our objective was to determine whether thresholds exist for associations between 25OHD levels and bone outcomes and if low 25OHD levels have adverse effects on bone health.

DESIGN

This is a cross-sectional study.

PARTICIPANTS

This study included secondary school students in Beijing, China, aged 12-15 years.

MEASURES

We measured serum 25OHD; bone mineral density (BMD) of total body, hip, and lumbar spine (LS); serum PTH; bone alkaline phosphatase (BAP); and tartrate-resistant acid phosphatase 5b (TRAP5b) in 222 healthy adolescents (111 girls, 111 boys).

RESULTS

The prevalence of low 25OHD was 61% (<30 nmol/liter) and 97% (<50 nmol/liter) (mean 25OHD, 30 nmol/liter). Dietary calcium intake was low (294 and 307 mg/d for boys and girls, respectively). In girls, break-points for 25OHD (nmol/liter) were: total body BMD 20 (95% confidence interval [CI], 14-27), hip BMD 25 (17-34), LS BMD 22 (14-30), TRAP5b 37 (22-52), and PTH 31 (23-38). In boys, break-points were: total body BMD 39 (24-55), TRAP5b 33 (20-45), and PTH 35 (27-43); no break-points were identified for hip and LS BMD. No break-points were identified for BAP in either gender. Below these break-points, higher 25OHD is associated with increased total body BMD, reduced PTH, and TRAP5b, whereas above these break-points, no such relationship exists.

CONCLUSIONS

Vitamin D deficiency and insufficiency is common in healthy Chinese adolescents. Attaining serum 25OHD levels of more than 20-37 nmol/liter in girls and 33-39 nmol/liter in boys had positive influences on BMD and bone remodelling markers. However, estimates may be affected by low calcium intake and low serum 25OHD levels, with 97% of adolescents having levels below 50 nmol/liter.