Relationship of nutrient intakes and bone mineral density of elderly women in Daegu, Korea

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.

Nutrition fact label (NFL) use is related to meeting the requirements for vitamins and minerals not listed on NFLs: Data from the Korea National Health and Nutritional Examination Survey VIII (2019-2021) for the prepandemic and pandemic periods

The credibility and wide usability of nutrition fact labels (NFLs) have increased due to the pandemic, which may lead to healthier nutritional choices. This cross-sectional study aimed to evaluate the association between NFL use and meeting the estimated average requirements (EARs) for vitamins and minerals not listed on NFLs during the prepandemic (2019, n = 6606) and pandemic periods (2020 and 2021, n = 12085) using KNHANES data. Household surveys, health behavior interviews, and health checkup examinations were conducted for all participants. Subjects were included in the unAware+noUse, Aware+noUse, and Aware+Use groups according to NFL usage, and nutritional intake was analyzed by the 24-hour recall method. Complex-sample multiple logistic regression analysis was used to determine the odds ratios (ORs) and 95% confidence intervals (CIs) for meeting the EARs according to NFL usage in the crude and adjusted (including metabolic conditions) models. The primary finding was that awareness and NFL use were associated with adequate intake above the EARs for vitamin A, vitamin B2, niacin, folate, Ca, Fe, and P; this association was more evident during the pandemic. After adjusting for covariates, during the pandemic, the ORs of meeting the EARs in the Aware+noUse group and Aware+Use group were 1.25 (CI 1.06-1.47) and 1.36 (CI 1.05-1.75) for vitamin A, 1.26 (CI 1.06-1.50) and 1.54 (CI 1.19-2.00) for vitamin B2, 1.32 (CI 1.13-1.56) and 1.46 (CI 1.15-1.85) for folate, and 1.46 (CI 1.06-2.00) and 1.73 (1.09-2.75) for P, respectively. Additionally, the ORs for niacin (1.21, 1.02-1.43) and Fe (1.29, 1.08-1.54) were significant in the Aware+noUse group, and that for Ca (1.39, 1.08-1.78) was significant in the Aware+Use group (all p <0.05). In conclusion, NFL awareness and use are associated with meeting the EARs for vitamins and minerals not listed on NFLs. For future recurring health crises, effective NFL use is necessary for healthy dietary practices.

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.

Peripheral skeleton bone strength is positively correlated with total and dairy protein intakes in healthy postmenopausal women

BACKGROUND

Bone mineral content (BMC) and bone mineral density (BMD) are positively correlated with dietary protein intakes, which account for 1-8% of BMC and BMD variances. However, the relation between bone strength and microstructure, which are variables that are not captured by areal bone mineral density (aBMD), and dietary protein intakes, particularly from specific dietary sources, has not been clearly established.

OBJECTIVE

We investigated the association between the peripheral skeleton-predicted failure load and stiffness, bone microstructure, and dietary protein intakes from various origins (animal, divided into dairy and nondairy, and vegetable origins) in healthy postmenopausal women.

DESIGN

In a cross-sectional study in 746 Caucasian women aged 65.0 ± 1.4 y, we measured the aBMD with the use of dual-energy X-ray absorptiometry, the distal radius and tibia bone microstructures with the use of high-resolution peripheral quantitative computerized tomography, and bone strength with the use of a finite element analysis, and we evaluated dietary protein and calcium with the use of a validated food-frequency questionnaire.

RESULTS

Mean dietary calcium and protein intakes were greater than recommended amounts for this class of age. The predicted failure load and stiffness at the distal radius and tibia were positively associated with total, animal, and dairy protein intakes but not with vegetable protein intake. Failure load differences were accompanied by modifications of the aBMD and of cortical and trabecular bone microstructures. The associations remained statistically significant after adjustment for weight, height, physical activity, menopause duration, calcium intake, and the interaction between calcium and protein intake. A principal component analysis of the volumetric BMD and bone microstructure indicated that trabecular bone mainly contributed to the positive association between protein intakes and bone strength.

CONCLUSIONS

These results, which were recorded in a very homogeneous population of healthy postmenopausal women, indicate that there is a beneficial effect of animal and dairy protein intakes on bone strength and microstructure. Specifically, there is a positive association between the bone failure load and stiffness of the peripheral skeleton and dietary protein intake, which is mainly related to changes in the trabecular microstructure. This trial was registered at www.controlled-trials.com as ISRCTN11865958.

Prevalence of osteoporosis according to nutrient and food group intake levels in Korean postmenopausal women: using the 2010 Korea National Health and Nutrition Examination Survey Data

BACKGROUND/OBJECTIVES

Women's bone health status is closely related with environmental factors and lifestyle factors. The purpose of this study is to evaluate the dietary risks of osteoporosis and osteopenia for Korean postmenopausal women.

SUBJECTS/METHODS

The data from 1,433 subjects from the 2010 KNHANES were used and divided into three groups: normal, osteopenia, and osteoporosis group using bone mineral density (BMD). Nutrient intakes and food intake frequency were evaluated. Logistic regression analysis was applied to determine the odds ratios for osteoporosis and osteopenia.

RESULTS

The RNI percentage of each nutrient and food intake frequency from 12 food groups decreased as bone mineral density status deteriorated. Risk for osteoporosis of low calcium (Ca) intake, under the EAR, showed an odds ratio of 2.13(95% CI; 1.26-3.61, P < 0.05). Higher intake frequency showed preventive effect from osteoporosis compared to lower intake frequency in such food group as dairy products (ORs 0.40, CI 0.21-0.75), beans (ORs 0.49, CI 0.29-0.83), seaweeds (ORs 0.55, CI 0.32-0.94), fish (ORs 0.56, CI 0.32-0.98), and fruits (ORs 0.42, CI 0.23-0.79) after adjusting for age.

CONCLUSION

To prevent osteoporosis in later life, sufficient Ca intake and more frequent intakes of foods containing Ca such as dairy products, beans, fish, seaweeds, and fruits, which help in Ca absorption, should be stressed for Korean postmenopausal women.

Poor Socioeconomic and Nutritional Status Are Associated with Osteoporosis in Korean Postmenopausal Women: Data from the Fourth Korea National Health and Nutrition Examination Survey (KNHANES) 2009

OBJECTIVE

As the population ages, osteoporosis is a growing global public health problem. This study examined potential risk factors associated with osteoporosis in a nationally representative sample of Korean postmenopausal women.

METHODS

This study used data from a nationally representative sample of Korean menopausal women participating in the Korea National Health and Nutrition Examination Survey KNHANES 2009 (n = 1467; mean age ± SE = 65.2 ± 0.3 years). Bone mineral density of total femur, femoral neck, and spine was measured by dual-energy X-ray absorptiometry. Osteoporosis was determined as t-score of -2.5 or below in at least 1 of the 3 sites. Menopausal status was confirmed by self-reports.

RESULTS

About 41% of the study sample met the criteria for osteoporosis. Poor socioeconomic status, lower BMI, and shorter estrogen exposure duration were significantly associated with osteoporosis in the study sample. Poor dietary intake was also related to osteoporosis. In the age- and energy-adjusted logistic regression models, participants consuming less protein, vitamin B2, or vitamin C than the estimated average requirement (EAR) showed higher odds of having osteoporosis than their counterparts. Participants consuming no milk or milk products had 45% increased odds of having osteoporosis than those consuming milk or milk products.

CONCLUSION

The findings of this study suggest several risk factors associated with osteoporosis, which can be addressed in the development and implementation of tailored nutritional interventions to promote the bone health of Korean postmenopausal women.

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

BACKGROUND/OBJECTIVES

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

SUBJECTS/METHODS

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

RESULTS

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

CONCLUSIONS

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

Dairy food intake, peripheral bone structure, and muscle mass in elderly ambulatory women

Previous studies suggest that dairy intake may be associated with reduced bone and muscle loss with aging, but there are limited data in the very old. We evaluated the association between intake of dairy foods and peripheral bone structure and muscle mass in 564 elderly women aged 80 to 92 (mean 84.7) years, who were participants of the Calcium Intake Fracture Outcome Study/CAIFOS Aged Extension Study (CAIFOS/CARES) cohort and attended the 10-year follow-up. Assessments included dairy consumption (milk, yogurt, and cheese) by a validated food frequency questionnaire, 15% tibia bone mass, area and volumetric bone mineral density (vBMD) by peripheral quantitative computed tomography (pQCT), and appendicular bone and skeletal muscle mass by dual-energy X-ray absorptiometry (DXA). Women were categorized according to tertiles of dairy intake: first tertile (≤ 1.5 servings/d), second tertile (1.5 to 2.2 servings/d) and third tertile (≥ 2.2 servings/d). Controlling for confounding factors, pQCT assessment at the 15% tibia showed that compared with those in the first tertile of dairy intake, women in the third tertile had 5.7% greater total bone mass (p = 0.005), principally because of an increase in cortical and subcortical bone mass (5.9%, p = 0.050), resulting in a 6.2% increase in total vBMD (p = 0.013). Trabecular but not cortical and subcortical vBMD was also higher (7.8%, p = 0.044). DXA assessment showed that women in the third tertile of dairy intake had greater appendicular bone mass (7.1%, p = 0.007) and skeletal muscle mass (3.3%, p = 0.014) compared with tertile 1. The associations with bone measures were dependent on dairy protein and calcium intakes, whereas the association with appendicular muscle mass was not totally dependent on dairy protein intake. Our results suggest a positive association of dairy intake with appendicular bone mineralization and muscle mass in elderly women. Because many fractures in this age group are of the appendicular skeleton often associated with falls, dairy intake may be a modifiable lifestyle factor contributing to healthy aging.

Major nutrient patterns and bone mineral density among postmenopausal Iranian women

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

Effects of calcium intake, milk and dairy product intake, and blood vitamin D level on osteoporosis risk in Korean adults: analysis of the 2008 and 2009 Korea National Health and Nutrition Examination Survey

This study was performed to determine the effects of dietary calcium (Ca) intake, milk and dairy product intake, and serum vitamin D level on bone mineral density. The survey data from the 2008-2009 Korea National Health and Nutrition Examination Survey (KNHANES) for adults (3,819 males, 5,625 females) aged > 20 years were examined; osteoporosis was defined according to the standards for Asian populations (T-score < -2.5). The risk for osteoporosis significantly decreased as Ca intake increased; this effect persisted (quartile 4 vs. quartile 1 of Ca intake: odds ratio [OR] 0.66; 95% confidence interval [CI]: 0.50-0.87) even after adjustment for gender, age, and other factors (body mass index, serum vitamin D, menstruation, female hormone intake, menopausal status, and the number of days per week of muscular strength exercise). Additionally, the risk for osteoporosis significantly decreased as the Ca/P ratio increased (quartile 4 vs. quartile 1: OR 0.76; 95% CI: 0.58-0.98). The degree of risk was 0.96 (0.66-1.38) in those who consumed < 1 portion of milk or dairy products daily, and 0.71 (0.53-0.96) in those who consumed > 1 portion per day, compared with those who had zero intake. The risk for osteoporosis significantly decreased as the serum 25(OH) vitamin D level increased. From these results, we advocate an increase in Ca, milk, and dairy product intake, and that serum 25(OH) vitamin D levels be maintained within the normal range, for the maintenance of bone health and the prevention of osteoporosis in adults.