Is phosphorus intake that exceeds dietary requirements a risk factor in bone health?

Oxidative regulation and cytoprotective effects of γ-polyglutamic acid on surimi sol subjected to freeze-thaw process

Frozen surimi sol incline to protein oxidation, but the quality control strategies based on oxidation remain limited. Hence, the antioxidant and cryoprotective effects of γ-polyglutamic acid (γ-PGA) on freeze-thawed salt-dissolved myofibrillar protein (MP) sol were investigated. Results showed that γ-PGA could effectively regulate protein oxidation of MP sol during freeze-thawing with lower carbonyl contents and less oxidative cross-linking. Meanwhile, γ-PGA primely maintained sol protein structures, showing reduction of 15.28% of salt soluble protein contents at γ-PGA addition of 0.04% under unoxidized condition. Additionally, compared to the control group without oxidation treatment, cooking loss of heat-induced gel with 0.04% γ-PGA decreased by 47.19%, while gel strength obviously increased by 57.22% respectively. Overall, moderate γ-PGA addition (0.04%) could inhibit protein oxidation of sol, further improving frozen stability of sol through hydrogen bonds and hydrophobic interaction, but excessive γ-PGA was adverse to sol quality due to severe cross-linking between γ-PGA and MP.

Association between ultra-processed food and osteoporosis: a cross-sectional study based on the NHANES database

AIM

Nutritional characteristics and additives in ultra-processed foods (UPF) are directly related to bone health. Physical activity as a modifiable lifestyle intervention also plays a possible role in bone mineral density (BMD), but effect of physical activity on association between UPF and osteoporosis is not fully understood. Herein, this study aims to explore the association of UPF with osteoporosis, and assess the potential mediating effects of some related factors on this pathway.

METHODS

Data of adults were extracted from the National Health and Nutrition Examination Survey (NHANES) database in this cross-sectional study. Associations of unprocessed/minimally processed food (MPF), processed culinary ingredient (PCI), processed foods (PF) and UPF with femur neck BMD, total femur BMD and osteoporosis were investigated using linear regression and weighted univariate and multivariate logistic regression analyses respectively. Subgroup analyses of age, gender, physical activity, poverty income ratio (PIR), hypertension, diabetes mellitus (DM), cardiovascular disease (CVD), and dyslipidemia were performed. The potential mediating and interaction effects of physical activity and related factors on association of UPF with osteoporosis were also assessed. The evaluation indexes were β, odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Among 10,678 eligible persons, 454 had osteoporosis. After adjusting for covariates, elevated UPF intake was associated with decreased demur neck and total femur BMD (β=-0.003). A higher UPF intake level (> 57.51%) was linked to higher odds of osteoporosis (OR = 1.789). These relationships were also significant in different subgroups. Physical activity had a potential mediating effect on the association between UPF and osteoporosis (OR = 0.47, mediating proportion = 21.54%).

CONCLUSION

UPF intake levels were associated with BMD and osteoporosis. Physical activity had an interaction effect with UPF, and had a potential mediating effect on relationship between UPF and osteoporosis.

Impact of Vitamin D Status and Nutrition on the Occurrence of Long Bone Fractures Due to Falls in Elderly Subjects in the Vojvodina Region of Serbia

Bone fractures are a significant public health issue among elderly subjects. This study examines the impact of diet and vitamin D status on the risk of long bone fractures due to falls in elderly subjects in Vojvodina, Serbia. Conducted at the University Clinical Center of Vojvodina in autumn/winter 2022-2023, the study included 210 subjects >65 years: 105 (F: 80/M: 15) with long bone fractures due to falls and 105 (F: 80/M: 15) controls. Groups were similar regarding age and BMI. Dietary intakes (by two 24-h recalls) and serum vitamin D levels were analyzed. The fracture group had a significantly lower median daily vitamin D intake (1.4 μg/day vs. 5.8 μg/day), intake of calcium, energy, proteins, fats, fibers, dairy products, eggs, fish, edible fats/oils, and a higher intake of sweets (p < 0.001 for all). Serum vitamin D levels were significantly lower in the fracture group (40.0 nmol/L vs. 76.0 nmol/L, p < 0.001). Logistic regression identified serum vitamin D as the most important protective factor against fractures, and ROC curve analysis indicated that serum vitamin D levels > 50.5 nmol/L decreased fracture risk. Nutritional improvements (increased intake of vitamin D and protein sources such as fish, eggs, and dairy), increased sun exposure, and routine vitamin D supplementation during winter are advised.

The relationship between dietary phosphorus and peripheral neuropathy in the general population of the United States: A preliminary research

BACKGROUND

Dietary phosphorus intake may serve as a potential predictor for peripheral neuropathy (PN). While past research has predominantly focused on the relationship between dietary phosphorus and bone health, relatively little is known about its role in the nervous system, particularly its association with PN.

METHODS

A cross-sectional study was conducted using data from NHANES 1999-2004. Participants were categorized into different dietary phosphorus intake groups, and the relationship between dietary phosphorus and PN was explored using multifactorial logistic regression, restricted cubic splines (RCS) analysis, and threshold effect analysis based on dietary intake.

RESULTS

The final study included 7726 participants, with 1378 diagnosed with PN and 6348 without. The study revealed a U-shaped non-linear relationship between dietary calcium and magnesium intake levels and PN, indicating that both excessive and insufficient dietary phosphorus intake may increase the risk of PN. Specifically, the incidence rates in the first quintile (1.433, 95% CI: 1.080-1.901), the fourth quintile (1.284, 95% CI: 1.000-1.648), and the fifth quintile (1.533, 95% CI: 1.155-2.035) significantly higher than the second quintile, with an overall trend showing a decrease followed by an increase in incidence rates. The results of RCS and threshold effect analysis indicate that when dietary phosphorus intake is below 939.44mg, the risk of PN decreases with increasing dietary phosphorus intake. On the contrary, when dietary phosphorus intake exceeds 939.44mg, the risk of PN increases with increasing dietary phosphorus intake.

CONCLUSION

This study reveals a U-shaped correlation between dietary phosphorus intake and PN. Future research should further elucidate the molecular mechanisms underlying this association, providing guidance for more scientifically informed dietary adjustments to prevent the occurrence of PN.

Micronutrients Importance in Cancer Prevention-Minerals

Cancer, a non-communicable disease with diverse kinds is one of the major global problems with high incidence and no proven method to prevent or treat. Minerals including trace elements are significant micronutrients for preserving the body's typical physiological function. In contrast to extremely processed industrial food, they are rich in natural sources of food and frequently included in nutritional supplements. The daily intake, storage capacities, and homeostasis of micronutrients depend on specific dietary practices in contemporary civilization and can be disturbed by various malignancies. Varied minerals have different effects on the status of cancer depending on how they affect these pathways. The outcomes could differ depending on the mineral such as calcium's supply and the cancer's location. A mineral called zinc helps the immune system function better and aids in wound healing. On the other hand, selenium exhibits anti-oxidant functions and has a dose-response relationship with many cancer types. However, this component can make the patient's condition worse. Although the body produces free radicals when iron is deficient, anaemia affects a patient's quality of life and ability to receive therapy. This chapter compiles the knowledge of minerals connected to unusual accumulation or depletion states in various malignancies.

Phosphorus - a scoping review for Nordic Nutrition Recommendations 2023

This scoping review aims to describe the totality of evidence for the role of phosphorus for health-related outcomes as a basis for setting and updating dietary reference values (DRVs). Phosphorus is needed in many biological processes, such as cellular metabolism and bone mineralization. Dietary phosphorus intake exceeds the previous Nordic Nutrition Recommendations (NNR2012) 2-3-fold in the Nordic countries. Intake from food additives is unknown but may play a significant role because the use of phosphate additives is common in the food industry. Bioavailability of phosphorus in plant-based products is lower than animal-based products. Nevertheless, bioavailability of phosphorus additives is higher. The main phosphorus-related health outcomes concern high phosphorus intake mainly from food additives with potential adverse effects on kidney, bone, and cardiovascular health.

Efficacy and Mechanisms of Oleuropein in Postmenopausal Osteoporosis

Background

Postmenopausal osteoporosis (PMOP) has a supernal morbidity rate in elderly females.

Objective

To appraise the effects of oleuropein on bone densitometry, bone metabolic index, oxidative stress, and inflammatory index in PMOP. In addition, the mechanism of olive bittersweet preventing bone loss was explored.

Methods

We grouped 80 salubrious female Sprague-Dawley rats into four teams: (1) sham operation team (sham, N = 20), (2) ovariectomy (OVX, N = 20), (3) castrated mice fed with oleuropein (OVX+ole, N = 20), and (4) castrated mice fed with estrogen (OVX+E2, N = 20). The ovariectomized SD rats were continuously raised with 200 μg/kg/dose of oleuropein. Bone mineral density and bone metabolism indexes were recorded. In order to assess the effectiveness of oleuropein on osteopenia, an enzyme-linked immunosorbent assay (ELISA) was devoted to examining the bone marrow indexes. The bone metabolism standards of PMOP rats were appraised by assessing serum levels of calcium, alkaline phosphatase (ALP), phosphorus, malondialdehyde (MDA), and nitrate content by experimental detection methods and levels of osteoclastogenesis inhibitory factor (OPG) and receptor activator for nuclear factor-κB ligand (RANKL) by ELISA. The OPG-RANK-RANKL signal passage was examined by Western blot (WB). We measured bone mineral density using dual-energy X-rays.

Results

Our animal experimental results indicated that oleuropein could significantly improve the bone mineral density of ovariectomized SD rats. In the meantime, it could reduce ending interleukin-6 (IL-6), malondialdehyde (MDA), nitrate, alkaline phosphatase (ALP), and phosphorus (P) serum concentration and would not affect Ca²⁺ concentration. In cell experiments, oleuropein also can promote the proliferation of osteoblasts. Furthermore, it can promote the expression of OPG protein and mRNA. In reverse, it inhibits the expression of RANKL protein and mRNA.

Conclusion

Oleuropein can not only improve the inflammatory and oxidative indexes of castrated rats but also prevent osteoporosis. Oleuropein avoids bone resorption by regulating OPG/RANKL expression.

Bioavailability of phosphorus and kidney function in the Jackson Heart Study

BACKGROUND

High phosphorus (P) exposure may have negative effects on kidney function. Nutrient databases provide total P, but bioavailability varies by source.

OBJECTIVES

We aimed to assess natural, added, and bioavailable P intake, and to relate these to estimated glomerular filtration rate (eGFR) in the Jackson Heart Study (JHS).

METHODS

A total of 3962 African-American participants of the JHS, aged 21-84 y, with urine albumin:creatinine ratio < 30 mg/g, and eGFR ≥ 60 mL · min-1 · 1.73 m-2, and without self-reported kidney disease, were included. Diet was assessed by FFQ. We assigned P in foods as naturally occurring or added, and weighted intake by P bioavailability, based on published literature. Relations between P variables and eGFR were assessed using multivariable regression.

RESULTS

Mean ± SE intakes were 1178 ± 6.7 mg and 1168 ± 5.0 mg for total P, 296 ± 2.8 mg and 291 ± 2.1 mg for bioavailable added P, and 444 ± 2.9 mg and 443 ± 2.2 mg for bioavailable natural P, in participants with eGFR = 60-89 and ≥90 mL · min-1 · 1.73 m-2, respectively. Major sources of total P included fish, milk, beef, eggs, cheese, and poultry; and of added P, fish, beef, processed meat, soft drinks, and poultry. After adjustment for confounders, P intakes, including total (β ± SE: -0.32 ± 0.15; P = 0.03), added (β ± SE: -0.73 ± 0.27; P = 0.01), bioavailable total (β ± SE: -0.62 ± 0.23; P = 0.01), and bioavailable added (β ± SE: -0.77 ± 0.29; P = 0.01), were significantly associated with lower eGFR. However, neither total nor bioavailable P from natural sources were associated with eGFR.

CONCLUSIONS

Added, but not natural, P was negatively associated with kidney function, raising concern about P additives in the food supply. Further studies are needed to improve estimation of dietary P exposure and to clarify the role of added P as a risk factor for kidney disease.

Minerals and Cancer: Overview of the Possible Diagnostic Value

Cancer is the second leading cause of death worldwide and is expected to increase by one-third over the next two decades, in parallel with the growing proportion of the elderly population. Treatment and control of cancer incidence is a global issue. Since there is no clear way to prevent or cure this deadly malignancy, diagnostic, predictive, and prognostic markers for oncological diseases are of great therapeutic value. Minerals and trace elements are important micronutrients for normal physiological function of the body. They are abundant in natural food sources and are regularly included in dietary supplements whereas highly processed industrial food often contains reduced or altered amounts of them. In modern society, the daily intake, storage pools, and homeostasis of these micronutrients are dependent on certain dietary habits and can be thrown out of balance by malignancies. The current work summarizes the data on minerals and trace elements associated with abnormal accumulation or depletion states in tumor patients and discusses their value as potential tumor-associated biomarkers that could be introduced into cancer therapy.

Nutrition, Physical Activity, and Dietary Supplementation to Prevent Bone Mineral Density Loss: A Food Pyramid

Bone is a nutritionally modulated tissue. Given this background, aim of this review is to evaluate the latest data regarding ideal dietary approach in order to reduce bone mineral density loss and to construct a food pyramid that allows osteopenia/osteoporosis patients to easily figure out what to eat. The pyramid shows that carbohydrates should be consumed every day (3 portions of whole grains), together with fruits and vegetables (5 portions; orange-colored fruits and vegetables and green leafy vegetables are to be preferred), light yogurt (125 mL), skim milk (200 mL,) extra virgin olive oil (almost 20 mg/day), and calcium water (almost 1 l/day); weekly portions should include fish (4 portions), white meat (3 portions), legumes (2 portions), eggs (2 portions), cheeses (2 portions), and red or processed meats (once/week). At the top of the pyramid, there are two pennants: one green means that osteopenia/osteoporosis subjects need some personalized supplementation (if daily requirements cannot be satisfied through diet, calcium, vitamin D, boron, omega 3, and isoflavones supplementation could be an effective strategy with a great benefit/cost ratio), and one red means that there are some foods that are banned (salt, sugar, inorganic phosphate additives). Finally, three to four times per week of 30-40 min of aerobic and resistance exercises must be performed.

Effects and interaction of dietary calcium and non-phytate phosphorus for slow-growing yellow-feathered broilers during the starter phase

Calcium (Ca) and non-phytate phosphorus (NPP) are fundamental minerals for bone formation and growth, and optimizing their level is required in broiler production. This experiment was conducted to investigate the effect and interaction of dietary Ca and NPP on growth performance, tibial characteristics and biochemical variables for slow-growing yellow-feathered broilers during 1-28 d (the starter phase). Seven hundred and twenty hatchling female broilers were randomly divided into nine groups, which received three levels of Ca (0.80%, 0.90%, 1.00%) each with three levels of NPP (0.40%, 0.45%, 0.50%). The results showed: (1) Dietary Ca level influenced (P < 0.05) the feed to gain ratio (F:G) and average daily feed intake (ADFI). Compared with broilers provided 1.00% Ca, ADFI of birds provided with 0.80% or 0.90% Ca and F:G of those with 0.90% Ca were decreased (P < 0.05). Dietary NPP level did not affect (P > 0.05) growth performance of broilers. (2) Dietary Ca affected (P < 0.05) tibial length. Compared with birds provided with 0.80% Ca, the length of tibia was decreased (P < 0.05) in birds received 1.00% Ca. Interactions between dietary Ca and NPP were observed (P < 0.05) on ash content, breaking strength and bone density of tibia. These three characteristics were better when birds received 0.90% Ca and 0.40% NPP or 1.00% Ca and 0.45% NPP. (3) Dietary Ca significantly affected (P < 0.05) the activity of alkaline phosphatase (ALP) in serum with decreased activity in birds fed 0.80% or 0.90% Ca. The dietary NPP influenced (P < 0.05) the contents of Ca in serum. Serum Ca was increased when birds were provided 0.40% NPP compared with other levels (P < 0.05). Again, there was interaction between Ca and NPP in diet on the contents of phosphorus (P) in serum (P < 0.05). In conclusion, interactions occurred between dietary Ca and NPP level on tibial breaking strength, density, ash content, and the content of P in the serum of young yellow-feathered broilers. Furthermore, dietary Ca affected ADFI, F:G and serum ALP activity, and dietary NPP also affected the P content in serum. Considering all indicators, 0.90% Ca and 0.40% NPP are optimal for slow-growing yellow-feathered broilers during 1-28 d of age.

Sugar-sweetened beverage consumption and bone health: a systematic review and meta-analysis

BACKGROUND

Current evidence demonstrate that sugar-sweetened beverages (SSBs) and bone health are related; however, there has been only a few reviews on the link between SSBs and bone health. A systematic review and meta-analysis was performed to investigate the association between SSBs consumption and bone health in chidren and adults.

METHODS

Relevant studies of SSBs and bone health published up to 15 March 2021 were searched using PubMed, the Web of Science, Cochrane Library, and a reference search. A random-effects meta-analysis was conducted to estimate the standardized mean difference (SMD). Subgroup analyses were performed to identify whether effects were modified by age, sex, measured skeletal sites, type of SSBs, and SSBs intake questionnaire.

RESULTS

Twenty-six publications including 124,691 participants were selected on the review. The results from this meta-analysis showed a significant inverse association between SSBs intake and bone mineral density (BMD) in adults (ES: -0.66, 95% CI: - 1.01, - 0.31, n = 4312). Eighteen of the 20 studies included in the qualitative-only review in children and adults supported the findings from the meta-analysis. When subgroup analysis was performed according to skeletal site, a large effect was found on whole body BMD (ES: -0.97, 95% CI: - 1.54, - 0.40). There was a moderate effect on BMD in females (ES: -0.50, 95% CI: - 0.87, - 0.13). There was a moderate or large effect on BMD in individuals aged under 50 years (under 30 years: ES: -0.57, 95% CI: - 0.97, - 0.17; 30 to 50 years: ES: -1.33, 95% CI: - 1.72, - 0.93). High consumption of carbonated beverages had a moderate effect on BMD (ES: -0.73, 95% CI: - 1.12, - 0.35).

CONCLUSION

The meta-analysis showed that SSBs consumption such as carbonated beverages were inversely related to BMD in adults. Qualitative review supported the results of meta-analysis.

TRIAL REGISTRATION

This review was registered in the PROSPERO database under identifier CRD42020164428 .

The emerging role of phosphorus in human health

Phosphorus, an essential nutrient, performs vital functions in skeletal and non-skeletal tissues and is pivotal for energy production. The last two decades of research on the physiological importance of phosphorus have provided several novel insights about its dynamic nature as a nutrient performing functions as a phosphate ion. Phosphorous also acts as a signaling molecule and induces complex physiological responses. It is recognized that phosphorus homeostasis is critical for health. The intake of phosphorus by the general population world-wide is almost double the amount required to maintain health. This increase is attributed to the incorporation of phosphate containing food additives in processed foods purchased by consumers. Research findings assessed the impact of excessive phosphorus intake on cells' and organs' responses, and highlighted the potential pathogenic consequences. Research also identified a new class of bioactive phosphates composed of polymers of phosphate molecules varying in chain length. These polymers are involved in metabolic responses including hemostasis, brain and bone health, via complex mechanism(s) with positive or negative health effects, depending on their chain length. It is amazing, that phosphorus, a simple element, is capable of exerting multiple and powerful effects. The role of phosphorus and its polymers in the renal and cardiovascular system as well as on brain health appear to be important and promising future research directions.

Multi-element Analysis of Brain Regions from South African Cadavers

Trace elements are vital for a variety of functions in the brain. However, an imbalance can result in oxidative stress. It is important to ascertain the normal levels in different brain regions, as such information is still lacking. Therefore, this study aimed to provide baseline trace element concentrations from a South African population, as well as determine trace element differences between sex and brain regions. Samples from the caudate nucleus, putamen, globus pallidus and hippocampus were analysed using inductively coupled plasma mass spectrometry. Aluminium, antimony, arsenic, barium, boron, cadmium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, mercury, molybdenum, nickel, phosphorus, potassium, selenium, silicon, sodium, strontium, vanadium and zinc were assessed. A multiple median regression model was used to determine differences between sex and regions. Twenty-nine male and 13 female cadavers from a Western Cape, South African population were included (mean age 35 years, range 19 to 45). Trace element levels were comparable to those of other populations, although magnesium was considerably lower. While there were no sex differences, significant anatomical regional differences existed; the caudate nucleus and hippocampus were the most similar, and the globus pallidus and hippocampus the most different. In conclusion, this is the first article to report the trace element concentrations of brain regions from a South African population. Low magnesium levels in the brain may be linked to a dietary deficiency, and migraines, depression and epilepsy have been linked to low magnesium levels. Future research should be directed to increase the dietary intake of magnesium.

Effects and interaction of dietary calcium and nonphytate phosphorus for slow-growing yellow-feathered broilers between 56 and 84 d of age

This experiment investigated the effect and interaction of dietary calcium (Ca) and nonphytate phosphorus (NPP) on growth performance, tibial characteristics, carcass traits, and meat quality for slow-growing yellow-feathered broilers during 56 to 84 d of age. A 3 × 3 factorial arrangement was used, and 720 56-day-old broilers were randomly divided into 9 groups and fed with diets containing different levels of Ca (0.70, 0.80, 0.90%) and NPP (0.30, 0.35, 0.40%) for 28 d. The dietary Ca level affected the ADFI of yellow-feathered broilers (P < 0.05), and the ADFI of birds fed with 0.90% Ca was increased (P < 0.05) compared with that of birds fed with 0.70% Ca.  Birds received 0.35 or 0.40% NPP had higher final BW, ADG, and ADFI than those fed with 0.30% NPP (P < 0.05). The tibial diameter of birds fed with 0.80% Ca was increased compared with that of other groups (P < 0.05). The dietary NPP level did not affect tibial characteristics (P > 0.05). The dietary Ca level did not affect carcass traits (P > 0.05). When broilers were fed with 0.30% P, the semieviscerated percentage was increased compared with birds fed with 0.40% NPP (P < 0.05). The dietary Ca level had significant effects on the L∗ value and shear force of the breast muscle, and the dietary NPP level affected the L∗ value and drip loss of the breast muscle (P < 0.05). Furthermore, the effect of interaction between the level of Ca and NPP was observed on the L∗ and a∗ value (P < 0.05). In conclusion, dietary Ca had influence on performance, tibial characteristics, and meat quality of yellow-feathered broilers, and dietary NPP affected performance, tibial characteristics, and carcass traits. Furthermore, the effect of interaction between the dietary Ca and NPP level was observed on carcass traits and meat quality. Considering all aforementioned indicators, 0.80% Ca and 0.35% NPP were recommended for slow-growing yellow-feathered broilers aged 57 to 84 d of age.

Gluten-Free Diet in Prisons in Poland: Nutrient Contents and Implementation of Dietary Reference Intake Standards

The gluten-free diet (GFD) requires special attention from nutritionists due to the potential risk of nutrient deficiencies in its users. This risk may be greater when this type of nutrition is implemented in prisons due to the limited possibilities of external control, a low catering budget for meals, and insufficiently defined recommendations regulating nutrition for prisoners. The aim of the present study was to assess the nutritional value of GFD and regular diet meals served in some Polish prisons and to compare the values to the dietary reference intake (DRI) standards. Using a specialized computer program, 7-day menus of both types of diet provided in 10 prisons were analyzed. The percentage coverage of the DRI was calculated based on the recommendations of the Polish National Food and Nutrition Institute. GFD was characterized by lower average contents of energy and 11 out of 14 essential nutrients, i.e., protein, carbohydrates, dietary fiber, starch, ash, sodium, calcium, iron, zinc, folate, and vitamin B12. The average content of phosphorus, niacin, and riboflavin in the gluten-free diet was higher than that in the regular diet. It was shown that the meals in GFD and the regular diet did not provide the recommended amounts of calcium (38 and 44% DRI, respectively), vitamin D (29 and 30% DRI), vitamin C (86 and 76% DRI), and folate (51 and 56% DRI). In turn, the supply of sodium, phosphorus, copper, and vitamins A and B6 substantially exceeded the recommended levels. The results indicate a need for greater quality control of GFD meals served in catering facilities. It is also necessary to develop legal provisions that will regulate more specifically the nutrition for prisoners in terms of an adequate supply of minerals and vitamins.

Bioavailability of Micronutrients From Nutrient-Dense Whole Foods: Zooming in on Dairy, Vegetables, and Fruits

In order to fully exploit the nutrient density concept, thorough understanding of the biological activity of single nutrients in their interaction with other nutrients and food components from whole foods is important. This review provides a narrative overview of recent insights into nutrient bioavailability from complex foods in humans, highlighting synergistic and antagonistic processes among food components for two different food groups, i.e., dairy, and vegetables and fruits. For dairy, bioavailability of vitamins A, B2, B12 and K, calcium, phosphorous, magnesium, zinc and iodine are discussed, whereas bioavailability of pro-vitamin A, folate, vitamin C and K, potassium, calcium, magnesium and iron are discussed for vegetables and fruits. Although the bioavailability of some nutrients is fairly well-understood, for other nutrients the scientific understanding of uptake, absorption, and bioavailability in humans is still at a nascent stage. Understanding the absorption and bioavailability of nutrients from whole foods in interaction with food components that influence these processes will help to come to individual diet scores that better reflect absorbable nutrient intake in epidemiologic studies that relate dietary intake to health outcomes. Moreover, such knowledge may help in the design of foods, meals, and diets that aid in the supply of bioavailable nutrients to specific target groups.

Nutrient contents predict the bamboo-leaf-based diet of Assamese macaques living in limestone forests of southwest Guangxi, China

Determining the nutrient factors influencing food choice provides important insight into the feeding strategy of animals, which is crucial for understanding their behavioral response to environmental changes. A bamboo-leaf-based diet is rare among mammals. Animals' food choice and nutritional goals have been explained by several frameworks; however, the influence of nutrients on food choice in bamboo-leaf-based macaques is not yet available. Assamese macaques (Macaca assamensis) inhabiting limestone forests are characterized by such a bamboo-leaf-based diet, predominantly consuming young leaves of Bonia saxatilis, a shrubby, karst-endemic bamboo. We studied the feeding behavior of one group of Assamese macaques using instantaneous scan sampling in limestone forests of the Guangxi Nonggang National Nature Reserve in southwest Guangxi, China. We compared the nutrient content of staple food and nonfood items and examine the role of key nutrients in the food selection of macaques. Our results showed that young leaves of bamboo B. saxatilis contained more water, crude protein, phosphorus, and less tannin than nonfood items. Furthermore, staple foods contained a higher content of water and less content of calcium than nonfood items. More specifically, quantities of water, crude protein, calcium, and phosphorus in food items were critical factors affecting feeding time on a specific plant item. Our results suggest that young bamboo leaves could meet macaques' required protein and water intake, while enabling them to maintain their mineral balance, consequently facilitating to maintain the primates' bamboo-leaf-diet in the limestone forest. Our findings confirm the effects of nutrient contents in food choice of Assamese macaques, highlighting the importance of the nutrient contents in maintaining their bamboo-based diet and the need to increase the knowledge on their nutritional strategy adapted to the bamboo-dominated diet inhabiting the unique limestone habitat.

Implementation of Dietary Reference Intake Standards in Prison Menus in Poland

Adequate nutrition in prisons should constantly be monitored due to the limited possibilities of external control as well as the low catering budget for prison meals and poorly defined requirements in this regard. The aim of the study was to assess the nutritional value of meals served in Polish prisons. Using a computer program, 14-day regular and bland diets from 30 prisons were analyzed. The energy value of the meals and the percentage of energy provided by protein, fat, and carbohydrate contained therein were found to meet the recommendations of the Polish National Food and Nutrition Institute. The amount of minerals supplied with the diet did not cover the recommended dietary allowance (RDA) in the case of calcium and magnesium. Particularly disturbing was the excessive supply of sodium in the regular and bland diets, which covered 537% and 311% of the dietary reference intake (DRI), respectively, as well as phosphorus (194 and 192% of RDA). The largest vitamin deficiencies were recorded for vitamins D and C and folate. An especially excessive supply was observed for vitamins A and B₁₂. The type of diet significantly differentiated the average content of over half of the analyzed components, whereas the season of the year turned out to be statistically insignificant. The results of the present investigations indicate a need for development of more accurate legal provisions to regulate the nutrition in Polish prisons in terms of not only the energy value and macronutrient supply but also the intake of minerals and vitamins.

Association Between Diet, Physical Activity and Body Mass Index, Fat Mass Index and Bone Mineral Density of Soldiers of the Polish Air Cavalry Units

Research from recent years indicates a problem of excessive body weight among soldiers, who, due to the kind of work carried out, should possess good health and fitness levels. The aim of the study was to determine the association between diet and physical activity and the nutritional status of soldiers of the Polish Air Cavalry Units. One hundred and twenty male soldiers (aged 28 ± 5 years) completed a questionnaire (food frequency questionnaire, long-form International Physical Activity Questionnaire). Body composition was determined by bioelectrical impedance analysis, and bone calcification of the forearm was assessed by the DXA (Dual Energy X-ray Absorptiometry) densitometric method. This study confirmed the association between both the diet and physical activity and body mass index (BMI), fat mass index (FMI), and bone mineral density (BMD) expressed as T-score. Significant negative correlations were found between BMI and the frequency of consumption of cereal products, meat products and fish, and nonalcoholic beverages, between FMI and cereal products, and between BMD T-score and meat products and fish, fat, nuts, and grains, sweets and snacks, and nonalcoholic beverages. Physical activity expressed as metabolic equivalent (MET-minutes/week) negatively correlated with FMI (but not BMI) and positively correlated with the BMD T-score. This study confirmed numerous irregularities in eating behavior and in nutritional status indices; therefore, there is a need for nutritional education and further monitoring of both dietary behaviors and nutritional status of soldiers.

High calcium intake from fat-free milk, body composition and glycaemic control in adults with type 2 diabetes: a randomised crossover clinical trial

We evaluated the effects of high-Ca fat-free milk v. low-Ca control diet on adiposity and on glycaemic control. Fourteen subjects with type 2 diabetes (aged 49·5 (sd 8·6) years, BMI 29·4 (sd 4·5) kg/m2, low habitual Ca consumption (<600 mg/d)) were included in this randomised, crossover clinical trial. Subjects participated in two 12-week experimental sessions (high-Ca fat-free milk (HC) or low-Ca control (LC)) separated by 8-week washout. Subjects daily consumed in the laboratory a breakfast shake containing 700 mg (HC) or 6·4 mg (LC) of Ca. Energy-restricted diets containing 800 mg of dietary Ca/d were prescribed. Dietary records data indicated the consumption of 1200 mg of Ca/d during HC and of 525 mg of Ca/d during LC. There was a greater reduction in body weight, body fat mass, waist circumference and waist:hip ratio after HC. Serum 25-hydoxyvitamin D and homeostatic model assessment-2 β-cell function (HOMA2-%B) increased, and serum uric acid, parathormone (PTH) and glycated Hb (HbA1c) concentrations reduced after HC. In addition, changes from baseline in terms of serum uric acid, glucose, HbA1c and PTH concentrations were lower, and those of HOMA2-%B, serum Ca and 25-hydoxyvitamin D were higher after the HC than after LC. The consumption of approximately three servings of fat-free milk and 1200 mg of dietary Ca/d enhanced weight loss, improved body composition and promoted glycaemic control in subjects with type 2 diabetes and low habitual Ca consumption (<600 mg/d).

The interplay between mineral metabolism, vascular calcification and inflammation in Chronic Kidney Disease (CKD): challenging old concepts with new facts

Chronic kidney disease (CKD) is one of the most powerful predictors of premature cardiovascular disease (CVD), with heightened susceptibility to vascular intimal and medial calcification associated with a high cardiovascular mortality. Abnormal mineral metabolism of calcium (Ca) and phosphate (P) and underlying (dys)regulated hormonal control in CKD-mineral and bone disorder (MBD) is often accompanied by bone loss and increased vascular calcification (VC). While VC is known to be a multifactorial process and a major risk factor for CVD, the view of primary triggers and molecular mechanisms complexity has been shifting with novel scientific knowledge over the last years. In this review we highlight the importance of calcium-phosphate (CaP) mineral crystals in VC with an integrated view over the complexity of CKD, while discuss past and recent literature aiming to highlight novel horizons on this major health burden. Exacerbated VC in CKD patients might result from several interconnected mechanisms involving abnormal mineral metabolism, dysregulation of endogenous calcification inhibitors and inflammatory pathways, which function in a feedback loop driving disease progression and cardiovascular outcomes. We propose that novel approaches targeting simultaneously VC and inflammation might represent valuable new prognostic tools and targets for therapeutics and management of cardiovascular risk in the CKD population.

Femoral Neck Fracture in Idiopathic Hypercalciuria with Excessive Cola Consumption: A Case Report

Idiopathic hypercalciuria is a metabolic defect characterized by excess renal calcium excretion, which can lead to bone mineral loss and an increased propensity to bony fractures. It is more commonly found among Caucasians and is present in the general population with a frequency of 5–10%, but can reach 45–50% in subjects affected by nephrolithiasis. Here we report the case of a young 35-year-old male who developed primary osteoporosis secondary to idiopathic hypercalciuria and sustained a femoral neck fracture after a minor-impact fall. Laboratory findings revealed high urine calcium, low serum potassium, and high serum alkaline phosphatase levels. Low-velocity traumatic bone injury was found in a young patient with hypercalciuria, which may indicate that bone status must be evaluated and followed up in these patients.

The effect of the food grade additive phosphate pre-treatment prior to the industrial cooking process in the quality of cooked peeled shrimp (Litopenaeus vannamei)

BACKGROUND

The food-grade additive phosphates have been highlighted as a potential alternative as a humectant agent to avoid large yield losses. Thus, the combined effect of phosphate with industrial cooking on shrimp quality was evaluated. Phosphate concentration (3% and 5%) and contact time (30 and 60 min) were evaluated as a pre-treatment to the industrial cooking of the peeled shrimp, in a shrimp processing plant. The yield process (%), physical quality [pH, color, texture, and water-holding capacity (WHC)] and chemical quality [moisture, protein, moisture/protein ratio, phosphate, and sodium] were also evaluated.

RESULTS

Our results showed that the food grade phosphates treatment showed a satisfactory effect on reduction of the weight loss, increase of the WHC (after cooking and posterior thawing), increase of the M/P ratio, improvement of the texture, decrease in the meat coloring, increase of the pH (0.3 to 0.5 units), but no affect on the shrimp overall quality (cooking yield, texture, WHC). Therefore, the residual phosphate and sodium contents increased proportionally with the concentration and time of contact with the additives, and slightly above the legal phosphate limit allowed.

CONCLUSION

We observed that the phosphate used as a pre-treatment of cooking step in shrimp plant processing improves the product quality, however, this treatment must be realized in accordance with the current federal legislation in each country. © 2018 Society of Chemical Industry.

A dietary pattern rich in calcium, potassium, and protein is associated with tibia bone mineral content and strength in young adults entering initial military training

Background

Stress fracture risk is elevated during initial military training (IMT), particularly in lower-extremity bones such as the tibia. Although the etiology of stress fractures is multifactorial, lower bone strength increases risk.

Objective

The objective of this study was to assess, through the use of peripheral quantitative computed tomography, whether adherence to a dietary pattern rich in calcium, potassium, and protein before IMT is positively associated with bone indexes in young adults entering IMT.

Design

A cross-sectional analysis was performed with the use of baseline data from 3 randomized controlled trials in Army, Air Force, and Marine recruits (n = 401; 179 men, 222 women). Dietary intake was estimated from a food-frequency questionnaire. A dietary pattern characterized by calcium, potassium, and protein was derived via reduced rank regression and a pattern z score was computed for each volunteer, where higher scores indicated greater adherence to the pattern. At the 4% (metaphysis) and 14% (diaphysis) sites of the tibia, bone mineral content (BMC), volumetric bone mineral density, robustness, and strength indexes were evaluated. Associations between dietary pattern z score as the predictor variable and bone indexes as the response variables were evaluated by multiple linear regression.

Results

Pattern z score was positively associated with BMC (P = 0.004) and strength (P = 0.01) at the metaphysis and with BMC (P = 0.0002), strength (P = 0.0006), and robustness (P = 0.02) at the diaphysis when controlling for age, sex, race, energy, smoking, education, and exercise. Further adjustment for BMI attenuated the associations, except with diaphyseal BMC (P = 0.005) and strength (P = 0.01). When height and weight were used in place of body mass index, the association with BMC remained (P = 0.046).

Conclusions

A dietary pattern rich in calcium, potassium, and protein is positively associated with measures of tibia BMC and strength in recruits entering IMT. Whether adherence to this dietary pattern before IMT affects injury susceptibility during training remains to be determined. These trials were registered at clinicaltrials.gov as NCT01617109 and NCT02636348.

Formation of calcium phosphate nanoparticles mediated by animal protein hydrolysates enhances calcium absorption by murine small intestine ex vivo

Animal protein intake appears to deliver available nanosized calcium to intestine.

Concomitant lysine and phosphorus addition to a wheat gluten protein diet highly amplified growth measures of rats

OBJECTIVE

In humans, the effects of lysine-fortified wheat on growth measures was much lower than that of animal experimentations that used phosphorus-containing mineral mix. It is known that wheat contains a limited amount of available phosphorus, which is believed to support growth. The aim of this study was to determine the involvement of phosphorus in growth measures of rats maintained on a lysine-supplemented wheat gluten diet.

METHODS

Forty male Sprague-Dawley (6 wk old) rats were randomly divided into four equal groups and fed wheat gluten protein (10%)-based diets with added lysine (0.6%), phosphorus (0.3%), or both (0.6% lysine and 0.3% phosphorus), ad libitum for 9 wk. Rats were monitored for changes in food intake, body weight, body and liver compositions, plasma urea nitrogen, and albumin.

RESULTS

The addition of lysine or phosphorus to wheat gluten-based diets increased energy intake modestly (∼15%), whereas their combination caused a higher increase (∼45%). Similarly, the magnitude of improvement in weight gain and energy efficiency by the addition of lysine or phosphorus (∼1g/d and 2.7g/MJ, respectively) was much lower than that of the combination (∼4g/d and 8.7g/MJ). In the phosphorus-containing groups, plasma urea nitrogen was significantly reduced and this was associated with higher body protein (%) and hepatic fat (%); whereas plasma albumin was significantly increased in the lysine-containing groups.

CONCLUSION

When using gluten protein, concomitant lysine and phosphorus availability is required to support growth measures, although phosphorus seems to have an independent effect on protein metabolism. Thus, human interventions should consider the improvement of the amino acid profile and phosphorus availability.

Analysis of lifestyle and bone mineralization in a population of Spanish young adults

OBJECTIVE

To analyze the environmental factors (nutritional status, levels of physical activity and nutritional habits) and their possible association with bone mass in a population of young adults.

METHODS

The study population consisted of 200 subjects (117 women and 83 men) aged between 18 and 25 years (mean age 20.4 years ±2.2 years). Body composition parameters were measured by an electronic balance (TANITA BC-418MA), nutritional habits were estimated by 72-h dietary recall, level of physical activity was assessed by the International Physical Activity Questionnaire (IPAQ) and bone mass was measured by ultrasonography at the calcaneus.

RESULTS

There were significant differences in bone mass values ​​according to gender (p= 0.013). Despite the fact that 70% of the subjects had a body mass index (BMI) within the normal range, 20% had overweight or obesity. 49% of the individuals had a moderate level of physical activity, although women had lower levels of physical activity than men (17.9% vs 8.4%). Most diets among young adults were hyperprotic, hyperlipidic and low-carbohydrates, with low-calcium and fiber intakes and high-phosphorus. Analysis of bone mass according to BMI showed higher values ​​as the weight category rises, with significant differences in women. Higher values ​​of bone mass were shown as the level of physical activity was higher, showing significant differences in males.

CONCLUSION

Our results show that BMI and level of physical activity are significantly associated with bone health in a population of young adults, suggesting the relevance of promoting healthy lifestyles as a strategy for the early prevention of osteoporosis.

THE USE OF VITAMINS AND MINERALS IN SKELETAL HEALTH: AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND THE AMERICAN COLLEGE OF ENDOCRINOLOGY POSITION STATEMENT

ABBREVIATIONS

25(OH)D = 25-hydroxyvitamin D; BMD = bone mineral density; CV = cardiovascular; GI = gastrointestinal; IOM = Institute of Medicine; PTH = parathyroid hormone; RCT = randomized controlled trial; αTF = α-tocopherol; ucOC = undercarboxylated osteocalcin; VKA = vitamin K antagonist; WHI = Women's Health Initiative.

Dairy products and bone health: how strong is the scientific evidence?

The relevance of dairy produce for the diminishment of osteoporotic risk is still a matter of scientific debate due to the outcome of a few single observational studies. This review will address the most robust point estimate on the role of dairy products, as reported in systematic reviews and meta-analyses on randomised controlled trials in the case of bone mineralisation or prospective studies in the case of fracture risk. Plain dairy products or those fortified with Ca and/or vitamin D improve total body bone mineral content (BMC) by 45-50 g over 1 year when the daily baseline Ca intake is lower than 750 mg in Caucasians and Chinese girls. In Caucasian and Chinese women, Ca from (fortified) dairy products increases bone mineral density (BMD) by 0·7-1·8 % over 2 years dependent on the site of measurement. Despite the results on BMC, there are currently no studies that have investigated the potential of dairy products to reduce fracture risk in children. In adult Caucasian women, daily intake of 200-250 ml of milk is associated with a reduction in fracture risk of 5 % or higher. In conclusion, the role of dairy products for BMC or BMD has been sufficiently established in Chinese and Caucasian girls and women. In Caucasian women, drinking milk also reduces fracture risk. More research on the role of dairy products within the context of bone health-promoting diets is needed in specific ethnicities, other than Chinese and Caucasians, and in men.

Habitual Intakes, Food Sources and Excretions of Phosphorus and Calcium in Three German Study Collectives

Phosphorus intake in Europe is far above recommendations. We present baseline data from three human intervention studies between 2006 and 2014 regarding intake and excretion of phosphorus and calcium. All subjects documented their nutritional habits in weighed dietary records. Fasting blood samples were drawn, and feces and urine were quantitatively collected. Dietary phosphorus intake was estimated based on weighed dietary records and urine phosphorus excretions. Food sources were identified by allocation to defined food product groups. Average phosphorus consumption was 1338 mg/day and did not change from 2006 to 2014, while calcium intake decreased during this period (1150 to 895 mg/day). The main sources for phosphorus intake were bread/cereal products, milk/milk products and meat/meat products/sausage products and the main sources of calcium intake included milk/milk products/cheese, bread/cereal products and beverages. There was no difference between estimated phosphorus intake from the weighed dietary records and urine phosphorus excretion. In conclusion, we demonstrated constant phosphorus intakes far above the recommendations and decreasing calcium intakes below the recommendations in three German collectives from 2006 to 2014. Furthermore, we could show in case of usual intakes that an estimated phosphorus intake from urine phosphorus excretion is similar to the calculated intake from weighed dietary records.

Contribution of Drinking Water Softeners to Daily Phosphate Intake in Slovenia

The cumulative phosphate intake in a typical daily diet is high and, according to several studies, already exceeds recommended values. The exposure of the general population to phosphorus via drinking water is generally not known. One of the hidden sources of phosphorus in a daily diet is sodium polyphosphate, commonly used as a drinking water softener. In Slovenia, softening of drinking water is carried out exclusively within the internal (household) drinking water supply systems to prevent the accumulation of limescale. The aim of the study was to determine the prevalence of sodium phosphates in the drinking water in Slovenia in different types of buildings, to determine residents' awareness of the presence of chemical softeners in their drinking water, and to provide an exposure assessment on the phosphorus intake from drinking water. In the current study, the presence of phosphates in the samples of drinking water was determined using a spectrophotometric method with ammonium molybdate. In nearly half of the samples, the presence of phosphates as water softeners was confirmed. The measured concentrations varied substantially from 0.2 mg PO4/L to 24.6 mg PO4/L. Nearly 70% of the respondents were not familiar with the exact data on water softening in their buildings. It follows that concentrations of added phosphates should be controlled and the consumers should be informed of the added chemicals in their drinking water. The health risks of using sodium polyphosphate as a drinking water softener have not been sufficiently investigated and assessed. It is highly recommended that proper guidelines and regulations are developed and introduced to protect human health from adverse effects of chemicals in water intended for human consumption.

Effects of Excessive Dietary Phosphorus Intake on Bone Health

PURPOSE OF REVIEW

The purpose of this review is to provide an overview of dietary phosphorus, its sources, recommended intakes, and its absorption and metabolism in health and in chronic kidney disease and to discuss recent findings in this area with a focus on the effects of inorganic phosphate additives in bone health.

RECENT FINDINGS

Recent findings show that increasing dietary phosphorus through inorganic phosphate additives has detrimental effects on bone and mineral metabolism in humans and animals. There is new data supporting an educational intervention to limit phosphate additives in patients with chronic kidney disease to control serum phosphate. The average intake of phosphorus in the USA is well above the recommended dietary allowance. Inorganic phosphate additives, which are absorbed at a high rate, account for a substantial and likely underestimated portion of this excessive intake. These additives have negative effects on bone metabolism and present a prime opportunity to lower total phosphorus intake in the USA. Further evidence is needed to confirm whether lowering dietary phosphorus intake would have beneficial effects to improve fracture risk.

Dietary Phosphorus Intake and the Kidney

Although phosphorus is an essential nutrient required for multiple physiological functions, recent research raises concerns that high phosphorus intake could have detrimental effects on health. Phosphorus is abundant in the food supply of developed countries, occurring naturally in protein-rich foods and as an additive in processed foods. High phosphorus intake can cause vascular and renal calcification, renal tubular injury, and premature death in multiple animal models. Small studies in human suggest that high phosphorus intake may result in positive phosphorus balance and correlate with renal calcification and albuminuria. Although serum phosphorus is strongly associated with cardiovascular disease, progression of kidney disease, and death, limited data exist linking high phosphorus intake directly to adverse clinical outcomes. Further prospective studies are needed to determine whether phosphorus intake is a modifiable risk factor for kidney disease.

Lack of Influence of Calcium/Phosphorus Ratio on Hip and Lumbar Bone Mineral Density in Older Americans: NHANES 2005-2006 Cross-Sectional Data

Objectives:

We sought to ascertain the effect of a low dietary calcium/phosphorus (Ca:P) ratio on the bone health of older adults in the United States. The present analysis assessed whether a high dietary consumption of P, which generally leads to a low dietary Ca:P ratio, has an unfavorable effect on the bone mineral density (BMD) of the hip and lumbar vertebrae in a representative sample of older US men and women.

Design:

For the 1228 men and women aged 50 to 70 and ≥71 years included in the National Health and Nutrition Examination Survey (NHANES) 2005 to 2006 cycle, quintiles of the dietary Ca:P ratio were tested for their association with hip and lumbar BMD after adjusting for body mass index (BMI). All data in this observational study were cross-sectional.

Results:

Women typically have higher dietary Ca:P ratios than men and lower BMDs. No trend emerged for any age or sex group when studying the relationship between the dietary Ca:P ratio and BMD with adjustment for BMI.

Conclusions:

A wide range of dietary Ca:P ratios in the diets of a cross-section of older adult men and women in the United States had little effect on the BMD of the hip (proximal femur) or the lumbar vertebrae (spine), even among those consuming large amounts of Ca supplements. Despite the lack of complete assessment of total P intake in the United States, these results suggest that high P consumption patterns and low dietary Ca:P ratios do not exert an adverse effect on BMD at major fracture sites in older adults.

Reported Dietary Intake, Disparity between the Reported Consumption and the Level Needed for Adequacy and Food Sources of Calcium, Phosphorus, Magnesium and Vitamin D in the Spanish Population: Findings from the ANIBES Study

Calcium, phosphorus, magnesium and vitamin D have important biological roles in the body, especially in bone metabolism. We aimed to study the reported intake, the disparity between the reported consumption and the level needed for adequacy and food sources of these four nutrients in the Spanish population. We assessed the reported intake for both, general population and plausible reporters. Results were extracted from the ANIBES survey, n = 2009. Three-day dietary reported intake data were obtained and misreporting was assessed according to the European Food Safety Authority (EFSA). Mean ± SEM (range) total reported consumption of calcium, phosphorus, magnesium, and vitamin D for the whole population were 698 ± 7 mg/day (71–2551 mg/day), 1176 ± 8 mg/day, (331–4429 mg/day), 222 ± 2 mg/day (73–782 mg/day), and 4.4 ± 0.1 µg/day (0.0–74.2 µg/day), respectively. In the whole group, 76% and 66%; 79% and 72%; and 94% and 93% of the population had reported intakes below 80% of the national and European recommended daily intakes for calcium, magnesium and vitamin D, respectively; these percentages were over 40% when the plausible reporters were analysed separately. The main food sources were milk and dairy products for calcium and phosphorus, cereals and grains for magnesium and fish for vitamin D. In conclusion, there is an important percentage of the Spanish ANIBES population not meeting the recommended intakes for calcium, magnesium and vitamin D.

Bone Mineral Density, Mechanical, Microstructural Properties and Mineral Content of the Femur in Growing Rats Fed with Cactus Opuntia ficus indica (L.) Mill. (Cactaceae) Cladodes as Calcium Source in Diet

Mechanical, microstructural properties, mineral content and bone mineral density (BMD) of the femur were evaluated in growing rats fed with Opuntia ficus indica (L.) Mill. (Cactaceae) cladodes at different maturity stages as calcium source. Male weanling rats were fed with cladodes at early maturity stage (25 and 60 days of age, belonging to groups N-60 and N-200, respectively) and cladodes at late maturity stage (100 and 135 days of age, belonging to groups N-400 and N-600, respectively) for 6 weeks. Additionally, a control group fed with calcium carbonate as calcium source was included for comparative purposes. All diets were fitted to the same calcium content (5 g/kg diet). The failure load of femurs was significantly lower (p ≤ 0.05) in groups N-60 and N-200 in comparison to N-400, N-600 and control groups. The cortical width (Ct.Wi) and trabecular thickness (Tb.Th) of the femurs in control and N-600 groups were significantly higher (p ≤ 0.05) than Ct.Wi and Tb.Th of femurs in groups N-60 and N-200. Trabecular separation of the femurs in N-60 and N-200 groups showed the highest values compared with all experimental groups. The highest calcium content in the femurs were observed in control, N-600 and N-400 groups; whereas the lowest phosphorus content in the bones were detected in N-200, N-600 and N-400 groups. Finally, the BMD in all experimental groups increased with age; nevertheless, the highest values were observed in N-600 and control groups during pubertal and adolescence stages. The results derived from this research demonstrate, for the first time, that the calcium found in Opuntia ficus indica cladodes is actually bioavailable and capable of improving mineral density and mechanical and microstructural properties of the bones. These findings suggest that the consumption of cladodes at late maturity stage within the diet might have a beneficial impact on bone health.

Maternal vitamin D biomarkers are associated with maternal and fetal bone turnover among pregnant women consuming controlled amounts of vitamin D, calcium, and phosphorus

Vitamin D plays a central role in calcium homeostasis; however, its relationship with bone turnover during pregnancy remains unclear due to a lack of studies that have rigorously controlled for vitamin D and other nutrients known to influence bone metabolism. Similarly, prior investigations of the effect of pregnancy on bone turnover relative to the nonpregnant state may have been confounded by varying intakes of these nutrients. Nested within a controlled intake study, the present investigation sought to quantify associations between maternal vitamin D biomarkers and biochemical markers of bone turnover among pregnant (versus nonpregnant) women and their fetuses under conditions of equivalent and adequate intakes of vitamin D and related nutrients. Changes in markers of bone turnover across the third trimester were also examined. Healthy pregnant (26-29 wk gestation; n=26) and nonpregnant (n=21) women consumed 511IU vitamin D/d, 1.6g calcium/d, and 1.9g phosphorus/d for 10weeks while participating in a controlled feeding study featuring two choline doses. Based on linear mixed models adjusted for influential covariates (e.g., BMI, ethnicity, and season), pregnant women had 50-150% higher (P<0.001) concentrations of bone resorption markers than nonpregnant women. Among pregnant women, increases in maternal 25(OH)D across the study period were associated (P<0.020) with lower osteocalcin and deoxypyridinoline at study-end, and higher fetal osteocalcin. In addition, maternal free 25(OH)D, 1,25(OH)₂D and 24,25(OH)₂D tended to be negatively associated (P≤0.063) with maternal NTx at study-end, and maternal free 25(OH)D and 24,25(OH)₂D were positively associated (P≤0.021) with fetal CTx. Similarly, maternal 3-epi-25(OH)D₃ was negatively related (P≤0.037) to maternal NTx and deoxypyridinoline at study-end. These declines in bone resorption markers resulting from higher vitamin D biomarker concentrations among pregnant women coincided with increases in their albumin-corrected serum calcium concentrations, indicating that calcium transfer to the fetus was uncompromised. Notably, none of these associations achieved statistical significance among nonpregnant women. Overall, our study findings suggest that achieving higher maternal concentrations of vitamin D biomarkers might attenuate third-trimester bone resorption while ensuring sufficient calcium delivery to the fetus.

Modified Nutritional Recommendations to Improve Dietary Patterns and Outcomes in Hemodialysis Patients

The renal diet has traditionally been regarded as one of the most complex medical nutrition therapies to teach, understand, and implement. Specifically, patients are instructed to limit fruits, vegetables, nuts, legumes, dairy, and whole grains because of both phosphorus and potassium concerns. Furthermore, hemodialysis patients are often encouraged to decrease fluid intake to control interdialytic weight gain. These restrictions can result in frustration, lack of autonomy, and the perception that there is nothing left to eat. It is possible that the traditional renal diet may be liberalized, with a focus on whole foods low in sodium and phosphorus additives, to afford patients greater choices and ultimately improved outcomes. Therefore, the objective of this review is to concisely assess the evidence in support of a renal diet focused primarily on reducing the intake of sodium and inorganic phosphorus. Finally, the limited evidence for restrictions on dietary potassium intake is summarized.

Marginal Micronutrient Intake in High-Performance Male Wheelchair Basketball Players: A Dietary Evaluation and the Effects of Nutritional Advice

Wheelchair basketball has evolved into a high-performance sport over several years, and small variations in player performance can determine the difference between winning and losing. Therefore, adequate micronutrient intake may influence this difference if performance-promoting macronutrient intake and physical fitness are equal between teams. Seventeen elite male wheelchair basketball players belonging to the Spanish National Team participated in this study. Macro- and micronutrient intake were determined using a food-weighing diary over three consecutive days during three training camps in two consecutive years. Current Dietary Reference Intake levels were used to determine the adequacy of intake of seventeen micronutrients of particular interest for athletes. After categorizing the consumed foods into fourteen food groups according to the National Nutrient Database for Standard References (USDA) these groups were used to identify the best predictors of the adequacy of intake for each micronutrient. Total energy intake correlated positively with the adequacy of all micronutrient intake levels, except for vitamins A and E. Five B vitamins and phosphorus, selenium, and iron showed 100% adequacy. All other micronutrient intake levels were found to be inadequate, e.g., vitamin E (51% adequacy) and calcium (73%). The fruit, fish and cereal food groups were found to be predictors of adequate intake of most micronutrients. Together with energy intake (p = .009, η2 = 0.49), the intake of the fruit (p = .032, η2 = 0.39) and egg (p = .036, Kendall's W = 0.42) food groups increased significantly over time, along with improved iodine (p = .008, W = 0.61) and magnesium (p = .030, W = 0.44) adequacy levels. Because the adequacy of micronutrient intake correlates positively with energy intake (R = 0.64, p < .001), a varied diet that includes cereals, fish and fruits is especially important for players with low levels of energy intake. Supplements may be a possible solution if adequate micronutrient intake cannot be achieved through regular dietary intake alone. However, dietary analyses should be conducted on a regular basis throughout the year to improve the nutritional knowledge of the athletes and assure adequate micronutrient intake.

The Influence of Alcohol Consumption in Conjunction with Sex Hormone Deficiency on Ca/P Ratio in Rats

Deficiency of sex hormones and excessive alcohol consumption are factors that have been related to alterations in the pattern of bone mineralization and osteoporosis. The aim of this study was to evaluate possible alterations in the calcium/phosphorus (Ca/P) ratio in the femur of rats subjected to sex hormone deficiency and/or alcohol consumption. Methods. Female and male Wistar rats (n = 108) were divided into ovariectomized (Ovx), orchiectomized (Orx), or sham-operated groups and subdivided according to diet: alcoholic diet (20% alcohol solution), isocaloric diet, and ad libitum diet. The diets were administered for 8 weeks. The Ca/P ratio in the femur was analyzed by energy dispersive micro-X-ray spectrometer (μEDX). Results. Consumption of alcohol reduced the Ca/P ratio in both females and males. The isocaloric diet reduced the Ca/P ratio in females. In groups with the ad libitum diet, the deficiency of sex hormones did not change the Ca/P ratio in females or males. However, the combination of sex hormone deficiency and alcoholic diet presented the lowest values for the Ca/P ratio in both females and males. Conclusions. There was a reduced Ca/P ratio in the femur of rats that consumed alcohol, which was exacerbated when combined with a deficiency of sex hormones.

Intakes of Calcium and Phosphorus and Calculated Calcium-to-Phosphorus Ratios of Older Adults: NHANES 2005-2006 Data

Background: High intakes of dietary phosphorus (P), relative to calcium (Ca) intake, are associated with a lower calcium:phosphorus ratio (Ca:P) ratio which potentially has adverse health effects, including arterial calcification, bone loss, and death. A substantial percentage of older adults (50 to 70 and 71 plus years) who have a higher risk of fracture rate than younger adults typically have low intakes of dietary Ca that are dominated by higher intakes of dietary P from natural and fortified foods, and lower Ca:P ratios than desirable. Objective: This investigation was undertaken to examine Ca and P intakes and the resulting Ca:P ratios (by mass) across gender and older adult age groups, using data from the National Health and Nutrition Examination Survey (NHANES) 2005–2006. Design: NHANES data are based on a cross-sectional sample of the non-institutionalized United States (US) population within various regions. This sample is selected to be representative of the entire US population at all ages. National Cancer Institute (NCI) methods and SAS survey procedures were used for analyses. Ca:P ratios were calculated using total Ca from both foods and supplements, whereas P intakes were calculated from food composition values and supplements. The amounts of P additives in processed foods are not available. Results: Mean Ca and P intakes demonstrated lower intakes of Ca and higher intakes of P compared to current Recommended Dietary Allowances (RDAs). The Ca:P ratios in older male and female adults were influenced by both low-Ca and high-P dietary consumption patterns. Conclusions: Both low total Ca intakes and high P amounts contribute to lower Ca:P ratios, i.e., ~0.7:1.0, in the consumption patterns of older adults than is recommended by the RDAs, i.e., ~1.5:1.0. Whether Ca:P ratios lower than recommended contribute to increased risk of bone loss, arterial calcification, and all-cause mortality cannot be inferred from these data. Additional amounts of chemical P additives in the food supply may actually reduce even further the Ca:P ratios of older adults of both genders, but, without P additive data from the food industry, calculation of more precise ratios from NHANES 2005–2006 data is not possible.

Nutrient and food intakes in early life and risk of childhood fractures: a systematic review and meta-analysis

BACKGROUND

The identification of detrimental dietary patterns early in life may contribute to reducing the high incidence of fracture among healthy children. However, information based on a systematic review of the effect of various dietary foods and nutrients on fracture risk is lacking.

OBJECTIVE

We conducted a systematic review and meta-analysis of observational studies that examined the association between dietary intake or serum nutritional concentrations and childhood fractures.

DESIGN

Studies published up until June 2015 were identified on the basis of a literature search in Medline, Web of Science, and Scopus databases and by hand searching references by first author based on predefined inclusion criteria. A meta-analysis was carried out for case-control studies that examined differences in mean calcium intake in the case compared with the control group. Random-effects analysis was performed on the basis of the effect estimates derived as the differences in mean calcium intakes between cases and controls.

RESULTS

From a total of 1960 articles, we identified 18 observational studies, which were primarily case-control in design. Randomized controlled trials were absent, potentially because of unethical aspects related to the enrollment of children randomly assigned to certain dietary exposures and later fracture rates. Overall, fracture risk seemed to be associated with milk avoidance, high energy intake, high cheese intake, high intake of sugar-sweetened beverages, and no breastfeeding. The pooled effect size of the 9 case-control studies that examined mean calcium intake, which had appropriate data for the meta-analysis, showed no association (P = 0.99) with fair heterogeneity (I(2) = 69.3%, P = 0.001) with the use of the random-effects model.

CONCLUSIONS

On the basis of a systematic review of studies that were judged to be of high or medium quality, there is an indication that some nutritional factors seem to be associated with an increased fracture risk among children. The results may be inflated by selection bias, bias in diet reporting, or residual confounding. More high-quality longitudinal observational or intervention studies are needed on the subject.