Vitamin A intake, serum vitamin D and bone mineral density: analysis of the Korea National Health and Nutrition Examination Survey (KNHANES, 2008-2011)

Independent and combined associations of dietary antioxidant intake with bone mineral density and risk of osteoporosis among elderly population in United States

BACKGROUND

The influence of dietary antioxidant intake on the occurrence and progression of osteoporosis may be significant. However, to date, evidence on the link between combined effect of dietary antioxidants on bone mineral density (BMD) level and risk of osteoporosis is limited. We aimed to assess the independent and combined association of dietary antioxidant intake with BMD level and risk of osteoporosis among elderly population in United States through analysis of data in the National Health and Nutrition Examination Survey.

METHODS

The dietary antioxidant intake was assessed based on six antioxidants, including vitamin A, vitamin C, vitamin E, zinc, selenium, and total carotenoid. A composite dietary antioxidant index (CDAI) was used to evaluate the combined exposure of dietary antioxidant intake.

RESULTS

A total of 5618 participants were included. Higher dietary vitamin A, vitamin C, vitamin E, zinc, selenium, and total carotenoid, were positively associated with BMD level. Compared with participants in the first quartile, those in the higher quartile of vitamin E (Q4: OR 0.652; 95% CI 0.463-0.918), zinc (Q4: OR 0.581; 95% CI 0.408-0.826), and selenium (Q3: OR 0.673; 95% CI 0.503-0.899) were associated with decreased risk of overall osteoporosis. Furthermore, compared to those in the first quartile, participants in the highest quartile of CDAI were associated with increased total femur (β 0.019; 95% CI 0.007-0.032), femur neck (β 0.020; 95% CI 0.009-0.032), trochanter (β 0.012; 95% CI 0.001-0.023), and intertrochanter BMD level (β 0.022; 95% CI 0.007-0.037); participants in the highest quartile of CDAI were associated with decreased risk of overall osteoporosis (OR 0.536; 95% CI 0.376-0.763). Furthermore, the associations of CDAI with the BMD level and osteoporosis risk were more significant among female participants.

CONCLUSION

Our study provides evidence that a combination of dietary antioxidants intake was associated increased BMD level and decreased osteoporosis risk.

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

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

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Association between multiple vitamins and bone mineral density: a cross-sectional and population-based study in the NHANES from 2005 to 2006

BACKGROUND

Bone mineral density (BMD) alterations in response to multivitamin exposure were rarely studied. Our study assessed the association of coexposure to six types of vitamins (i.e., vitamins B12, B9, C, D, A and E) with BMD measurements in adults in the US.

METHODS

Data were collected from participants aged ≥ 20 years (n = 2757) in the U.S. National Health and Nutrition Examination Surveys (NHANES) from 2005 to 2006. Multiple linear regression, restricted cubic splines, principal component analysis (PCA) and weighted quantile sum (WQS) regression were performed for statistical analysis.

RESULTS

The circulating levels of vitamins B12 and C were positively associated with BMDs, and an inverted L-shaped exposure relationship was observed between serum vitamin C and BMDs. PCA identified two principal components: one for 'water-soluble vitamins', including vitamins B12, B9 and C, and one for 'fat-soluble vitamins', including vitamins A, D and E. The former was positively associated with total femur (β = 0.009, 95%CI: 0.004, 0.015) and femoral neck (β = 0.007, 95%CI: 0.002, 0.013) BMDs, and the latter was negatively associated with BMDs with non-statistical significance. The WQS index constructed for the six vitamins was significantly related to total femur (β = 0.010, 95%CI: 0.001, 0.018) and femoral neck (β = 0.008, 95%CI: 0.001, 0.015) BMDs, and vitamins B12 and C weighted the most. The WQS index was inversely related to BMDs with non-statistical significance, and vitamins E and A weighted the most.

CONCLUSION

Our findings suggested a positive association between water-soluble vitamin coexposure and BMD, and the association was mainly driven by vitamins B12 and C. Negative association between fat-soluble vitamin coexposure and BMD was indicated, mainly driven by vitamins E and A. An inverted L-shaped exposure relationship was found between vitamin C and BMD.

Vitamin A Update: Forms, Sources, Kinetics, Detection, Function, Deficiency, Therapeutic Use and Toxicity

Vitamin A is a group of vital micronutrients widely present in the human diet. Animal-based products are a rich source of the retinyl ester form of the vitamin, while vegetables and fruits contain carotenoids, most of which are provitamin A. Vitamin A plays a key role in the correct functioning of multiple physiological functions. The human organism can metabolize natural forms of vitamin A and provitamin A into biologically active forms (retinol, retinal, retinoic acid), which interact with multiple molecular targets, including nuclear receptors, opsin in the retina and, according to the latest research, also some enzymes. In this review, we aim to provide a complex view on the present knowledge about vitamin A ranging from its sources through its physiological functions to consequences of its deficiency and metabolic fate up to possible pharmacological administration and potential toxicity. Current analytical methods used for its detection in real samples are included as well.

Vitamin A and Bone Health: A Review on Current Evidence

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

Factors associated with bone mineral density in adults: a cross-sectional population-based study

OBJECTIVE

This study aimed to analyze the association between lumbar spine, femoral neck, total hip bone mineral density (biophysical bone health assessment parameter), and sociodemographic, anthropometric, behavioral, and health condition factors in Brazilian adults.

METHOD

This is a cross-sectional, population-based study performed with individuals of both genders, aged between 20 and 59 (n=701). The dependent variables were evaluated by Dual Energy X-ray Absorptiometry. The independent variables were evaluated through a questionnaire, anthropometric evaluation and blood collection. The association between bone mineral density and the independent variables was evaluated by linear regression analysis. All analyses were stratified by gender.

RESULTS

Men presented higher bone mineral density than women. Bone mineral density was inversely associated with age range and directly associated with nutritional status in both genders and in the three bone sites analyzed. In addition, 25 Hydroxyvitamin D deficient status among men and contraceptive use among women were associated with lower bone mineral density, and a significant association was only found with lumbar spine bone mineral density in women.

CONCLUSION

The factors associated with bone health among men were age, skin color, nutritional status, and vitamin D status. For women, the associated factors with bone health were age, skin color, nutritional status and contraceptive use.

RNA-seq reveals downregulated osteochondral genes potentially related to tibia bacterial chondronecrosis with osteomyelitis in broilers

Background

Bacterial chondronecrosis with osteomyelitis (BCO) develops in the growth plate (GP) of the proximal femur and tibia and is initiated by damage to the less mineralized chondrocytes followed by colonization of opportunistic bacteria. This condition affects approximately 1% of all birds housed, being considered one of the major causes of lameness in fast growing broilers. Although several studies have been previously performed aiming to understand its pathogenesis, the molecular mechanisms involved with BCO remains to be elucidated. Therefore, this study aimed to generate a profile of global differential gene expression involved with BCO in the tibia of commercial broilers, through RNA sequencing analysis to identity genes and molecular pathways involved with BCO in chickens.

Results

Our data showed 192 differentially expressed (DE) genes: 63 upregulated and 129 downregulated in the GP of the tibia proximal epiphysis of BCO-affected broilers. Using all DE genes, six Biological Processes (BP) were associated with bone development (connective tissue development, cartilage development, skeletal system development, organ morphogenesis, system development and skeletal system morphogenesis). The analyses of the upregulated genes did not indicate any significant BP (FDR < 0.05). However, with the downregulated genes, the same BP were identified when using all DE genes in the analysis, with a total of 26 coding genes explaining BCO in the tibia: ACAN, ALDH1A2, CDH7, CHAD, CHADL, COL11A1, COMP, CSGALNACT1, CYR61, FRZB, GAL3ST1, HAPLN1, IHH, KIF26B, LECT1, LPPR1, PDE6B, RBP4A, SERINC5, SFRP1, SOX8, SOX9, TENM2, THBS1, UCHL1 and WFIKKN2. In addition, seven transcription factors were also associated to BCO: NFATC2, MAFB, HIF1A-ARNT, EWSR1-FLI1, NFIC, TCF3 and NF-KAPPAB.

Conclusions

Our data show that osteochondral downregulated genes are potential molecular causes of BCO in broilers, and the bacterial process seems to be, in fact, a secondary condition. Sixteen genes responsible for bone and cartilage formation were downregulated in BCO-affected broilers being strong candidate genes to trigger this disorder.

Vitamin D and bone health in adults: a systematic review and meta-analysis

Low bone health is associated with vitamin D deficiency in older individuals; however, this association is not well established in adults. The aim of the study was to analyze the association between serum concentrations of 25-hydroxyvitamin D and bone health in adults by systematic review and meta-analysis. The search was carried out in the LILACS, PubMed, Scopus, Web of Science, ScienceDirect databases from March 2017 to October 2018 with adult individuals (20-59 years). Bone health was evaluation performed through dual X-ray absorptiometry and serum concentrations of 25(OH)D. The random effect model was used to analyze data from bone mineral content and bone mineral. Random effects models were used and the sources of heterogeneity were explored by means of meta-regression. Thirty-five articles were selected. There was positive correlation between vitamin D and bone health in most of the evaluated sites. Correlation was observed in the analysis of subgroups for lumbar spine among men. When stratified, the studies presented high heterogeneity, which was explained by the sample size, mean serum vitamin D levels and risk of bias. Vitamin D is positively correlated to bone health in adult individuals.

The safety of isotretinoin treatment in patients with bone fractures

Isotretinoin is widely applicable in dermatology, although it may develop severe side effects in the skeletal system. An intention of this review was to establish the safety of oral isotretinoin in patients with bone fractures. Both MEDLINE/Pubmed and SCOPUS databases were searched to investigate the influence of isotretinoin on the skeletal system. The drug shows a strong osteoporotic activity in rats whereas this effect is milder in humans. Biochemical markers of bone turnover remain unchanged except for serum calcium in patients receiving a high dose of isotretinoin. An excessive intake of vitamin A may impair functioning of vitamin D especially in people with a vitamin D deficiency, therefore a similar side effect may also occur in patients on isotretinoin treatment. We suggest reducing the use of isotretinoin after bone injury or continuing the treatment at low dosing with a concomitant correction of vitamin D and calcium status.

High Serum Retinol as a Relevant Contributor to Low Bone Mineral Density in Postmenopausal Osteoporotic Women

There is controversial information about the impact of vitamin A on bone. Some epidemiological studies show that excessive intake of vitamin A, or an excess of serum vitamin A, has related with adverse impact on bone mass; however, other studies did not find these links, and some authors have proposed that this vitamin might promote a better bone health. The present work aims to contribute to clarify the real role of vitamin A in bone tissue. For this purpose, a cross-sectional study of 154 osteoporotic non-treated postmenopausal women (> 65 years old) was carried out. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry. We assessed concentrations of serum retinol, osteocalcin, parathyroid hormone, alkaline phosphatase, calcium, and phosphorus. We also studied demographic and anthropometric parameters. Spearman's correlations between retinol levels and other variables found negative correlations with BMD in both lumbar spine (R = - 0.162, P < 0.01) and femoral neck (R = - 0.182, P < 0.01), as well as alkaline phosphatase (R = - 0.110; P < 0.05) and phosphorus (R = - 0.110; P < 0.05). A positive correlation between retinol and fertile window was observed (R = 0.158; P < 0.01). After multivariable adjustment, we still found a negative correlation between serum retinol and BMD, both at the lumbar spine (R = - 0.210; P < 0.01) and at the femoral neck (R = - 0.324, P < 0.001). It is concluded that elevated serum-retinol levels are associated with an increased risk of low bone mass and thus with osteoporotic fractures. Therefore, osteoporosis-risk assessment should include quantification of serum metabolite of vitamin A.

Consequences of Inadequate Intakes of Vitamin A, Vitamin B12, Vitamin D, Calcium, Iron, and Folate in Older Persons

Purpose of Review

This review broadly discusses the consequences of inadequate consumption, by deficit or excess, of selected micronutrients on the quality of life and morbidity during aging, specifically considering increases in life expectancy and the costs of care in the older persons.

Recent Findings

A literature review of the periods 2012 to 2018, focusing on vitamins A, B₁₂, and D, calcium, iron and folate, was completed as these micronutrients are found to significantly affect the aging process. Causation and application of these micronutrients to disorders related to aging are controversial and mixed. This review highlights research needs and controversial points on the role of these micronutrients.

Summary

Micronutrient deficiencies are a common and avoidable contributor to decreased quality of life and healthcare costs in the older persons. Further research is needed to determine adequate intakes and innovative uses, including appropriate thresholds for improved health outcomes for this population.

High levels of serum vitamin D are associated with a decreased risk of metabolic diseases in both men and women, but an increased risk for coronary artery calcification in Korean men

Background

There are conflicting results for relationships between serum vitamin D levels and metabolic diseases. The aim of this study was to investigate whether serum vitamin D levels were associated with various metabolic diseases including insulin resistance (IR), metabolic syndrome (MS), fatty liver (FL), and coronary artery calcification (CAC), along with assessing gender differences for these relationships in Korean adults.

Methods

A total of 180,918 subjects (98,412 men and 82,506 women) who participated in a comprehensive health examination in the 2012–2013 period at Kangbuk Samsung Hospital, College of Medicine, Sungkyunkwan University were included. Serum vitamin D and metabolic markers were analyzed and CAC was estimated. Subjects were divided according to quartile groups of serum vitamin D. To examine the relationships of serum vitamin D to metabolic diseases and metabolic factors, multivariate logistic analysis was conducted.

Results

High levels of serum vitamin D was associated with lower ORs for MS, IR and FL both in men and women (all p < 0.05). For men, ORs for CAC were significantly higher in third and the highest quartile groups for serum vitamin D in all the analyzed models (all p < 0.05). However, women showed no significant results between serum vitamin D and CAC.

Conclusions

High levels of serum vitamin D were associated with lower risk of MS, IR and FL in both Korean men and women, but were associated with higher risk of CAC only in men, and not in women.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-016-0432-3) contains supplementary material, which is available to authorized users.