Older adults’ beliefs, knowledge and preferences for achieving healthy vitamin D status: A narrative review

Autonomy and mobility are, in many cases, key elements underlying positive ageing. Vitamin D (vitD) is essential to maintaining musculoskeletal health and hence mobility; ensuring adequate vitD status is important in positive ageing. However, vitD deficiency persists in ~10–30% of older adults in the Western world. The aim of this review was to explore older adult vitD beliefs, knowledge and preferences, in order to identify means to prevent vitD deficiency respectful of older peoples’ autonomy. Academic search-engines were used to explore the research literature with the keywords: vitamin D; older adults; preferences; knowledge; practices; beliefs. 22 recent studies were identified; although the majority of older people knew of vitD, knowledge about increased fall risk secondary to deficiency was limited and knowledge did not always correlate with adequate intake or status. There was evidence of confusion regarding vitD food sources, sun-exposure and health benefits, and although General Practitioners were trusted information sources they often did not discuss vitD with patients. Preferences varied significantly depending on geographic location, ethnicity, socioeconomic status, education and cultural factors; overall, older people wanted more clear information about vitD. In conclusion, older people have a relatively high awareness of vitD, however, knowledge may be inaccurate and low in those most at risk, and knowledge of deficiency- associated fall risk is under-recognised. Furthermore, studies specifically addressing older adult preferences are lacking; an understanding of preferences, integrated into public health guidelines and implementation strategies, is key not only to decreasing the risk of vitamin D deficiency but also to enabling autonomy in older adults

Iron bioavailability from commercially available iron supplements

Purpose: Iron deficiency anaemia (IDA) is a global public health problem. Treatment with the standard of care ferrous iron salts may be poorly tolerated, leading to non-compliance and ineffective correction of IDA. Employing supplements with higher bioavailability might permit lower doses of iron to be used with fewer side effects, thus improving treatment efficacy. Here, we compared the iron bioavailability of ferrous sulphate tablets with alternative commercial iron products, including three liquid-based supplements. Methods: Iron bioavailability was measured using Caco-2 cells with ferritin formation as a surrogate marker for iron uptake. Statistical analysis was performed using one-way ANOVA followed by either Dunnett’s or Tukey’s multiple comparisons tests. Results: Spatone Apple® (a naturally iron-rich mineral water with added ascorbate) and Iron Vital F® (a synthetic liquid iron supplement) had the highest iron bioavailability. There was no statistical difference between iron uptake from ferrous sulphate tablets, Spatone® (naturally iron-rich mineral water alone) and Pregnacare Original® (a multimineral/multivitamin tablet). Conclusion: In our in vitro model, naturally iron-rich mineral waters and synthetic liquid iron formulations have equivalent or better bioavailability compared with ferrous iron sulphate tablets. If these results are confirmed in vivo, this would mean that at-risk groups of IDA could be offered a greater choice of more bioavailable and potentially better tolerated iron preparations

Nutritional quality of lunches served in South East England hospital staff canteens

Worksite canteens generally are characterized by obesogenic environments, which offer access to energy-dense foods and sugar-sweetened beverages rather than nutrient-rich food. This study assessed the nutritional quality of hot lunches offered in National Health Service (NHS) hospital staff canteens: 35 side dishes and 112 meals were purchased from 8 NHS hospital staff canteens. The meals were analyzed for portion size, energy, protein, total fat, saturated fatty acids (SFAs), salt, and the sodium to potassium ratio. The vegetarian and meat-based lunch meals served in the hospital staff canteens tended to be high in energy, total fat, saturated fatty acids, and salt: 40%, 59% and 67% of meat meals and 34%, 43%, and 80% of vegetarian meals were assigned the red traffic light label for total fat, salt, and SFAs per portion, respectively. Similar types of meals, but served in different hospitals, varied considerably in their nutritional quality. The consumption of some lunch meals could provide more than 50% of recommended total fat, SFAs, and salt for both men and women and daily energy for women. The majority of analyzed lunch meals were characterized by an unfavorable nutrient profile, and regular consumption of such meals may increase the risk of noncommunicable diseases

Effects of supplementation with beef or whey protein versus carbohydrate in master triathletes

Objective: The present study compares the effect of ingesting hydrolyzed beef protein, whey protein, and carbohydrate on performance, body composition (via plethysmography), muscular thickness, and blood indices of health, including ferritin concentrations, following a 10-week intervention program. Methods: After being randomly assigned to one of the following groups: Beef, Whey, or Carbohydrate, twenty four master-age male triathletes (n=8 per treatment) ingested 20 g of supplement, mixed with plain water once a day (immediately after training or before breakfast). All measurements were performed pre and post interventions. Results: Only Beef significantly reduced body mass (p=0.021) along with a trend to preserve or increase thigh muscle mass (34.1±6.1 vs 35.5± 7.4 mm). Both Whey (38.4±3.8 vs 36.9±2.8 mm) and Carbohydrate (36.0±4.8 vs 34.1±4.4 mm) interventions demonstrated a significantly (p<0.05) decreased vastus medialis thickness. Additionally, the Beef condition produced a significant (p<0.05) increase in ferritin concentrations (117±78.3 vs 150.5±82.8 ng/mL). No such changes were observed for the Whey (149.1±92.1 vs 138.5±77.7 ng/mL) and Carbohydrate (149.0±41.3 vs 150.0±48.1 ng/mL) groups. Furthermore, ferritin changes in the Beef group were higher than the modification observed in Whey (p<0.001) and Carbohydrate (p=0.025). No differences were found between Whey and Carbohydrate conditions (p=0.223). No further changes were observed. Conclusion: Ingesting a hydrolyzed beef protein beverage after workout or before breakfast (non training days) can be effective in preserving thigh muscle mass and in improving iron status in male master-age triathletes

Effects of supplementation with beef or whey protein versus carbohydrate in master triathletes

Objective: The present study compares the effect of ingesting hydrolyzed beef protein, whey protein, and carbohydrate on performance, body composition (via plethysmography), muscular thickness, and blood indices of health, including ferritin concentrations, following a 10-week intervention program. Methods: After being randomly assigned to one of the following groups: Beef, Whey, or Carbohydrate, twenty four master-age male triathletes (n=8 per treatment) ingested 20 g of supplement, mixed with plain water once a day (immediately after training or before breakfast). All measurements were performed pre and post interventions. Results: Only Beef significantly reduced body mass (p=0.021) along with a trend to preserve or increase thigh muscle mass (34.1±6.1 vs 35.5± 7.4 mm). Both Whey (38.4±3.8 vs 36.9±2.8 mm) and Carbohydrate (36.0±4.8 vs 34.1±4.4 mm) interventions demonstrated a significantly (p<0.05) decreased vastus medialis thickness. Additionally, the Beef condition produced a significant (p<0.05) increase in ferritin concentrations (117±78.3 vs 150.5±82.8 ng/mL). No such changes were observed for the Whey (149.1±92.1 vs 138.5±77.7 ng/mL) and Carbohydrate (149.0±41.3 vs 150.0±48.1 ng/mL) groups. Furthermore, ferritin changes in the Beef group were higher than the modification observed in Whey (p<0.001) and Carbohydrate (p=0.025). No differences were found between Whey and Carbohydrate conditions (p=0.223). No further changes were observed. Conclusion: Ingesting a hydrolyzed beef protein beverage after workout or before breakfast (non training days) can be effective in preserving thigh muscle mass and in improving iron status in male master-age triathletes

Effects of carbohydrates on iron metabolism in intestinal and liver cells

Iron deficiency and excess are worldwide public health problems. Studies suggest that carbohydrates such as fructose, and oligo-and polysaccharides (prebiotics), increase iron bioavailability, but results are inconclusive. There is also interest in whether iron and fructose contribute to the pathogenesis of colorectal cancer (CRC), hepatocellular carcinoma (HCC) and non-alcoholic fatty liver disease (NAFLD). Intake of sugars has increased in the past three decades, as has the prevalence and incidence of HCC and AFLD, while CRC remains one of the top three occurring malignancies in the developed world, making these questions particularly relevant at this time. The aims of this thesis were to study iron-carbohydrate effects on: non-haem iron bioavailability, and on the expression of genes and proteins related to CRC, HCC and NAFLD. The principal carbohydrates investigated were fructose, the related sweetener high fructose corn syrup (HFCS), and fructo- and galacto-oligosaccharide prebiotics (FOS&GOS, respectively). It was hypothesised that fructose, HFCS, and FOS&GOS would increase non-haem iron bioavailability, and that iron and fructose would alter expression of genes and proteins related to the pathogenesis of CRC, HCC and NAFLD. Two human in vitro cell lines were used to investigate these questions: Caco-2 and HepG2 cells, models of the small intestine and liver, respectively. The Caco-2 in vitro digestion model was used to examine fructose, HFCS, and FOS&GOS effects on iron bioavailability with ferritin formation as a surrogate marker for iron uptake. Ferritin formation was also utilised to assess iron uptake in HepG2 cells. Expression of iron homeostasis proteins was analysed by Western Blot and Polymerase Chain Reaction (PCR) to explore biological mechanisms underlying observed effects on iron bioavailability. Lastly, Caco-2 and HepG2 cells were treated with iron and fructose, and the effects on selected genes and proteins involved in CRC, HCC and NAFLD development were evaluated through microarray, PCR and Western Blot analysis. Results indicated that fructose in a water-based matrix with added ferric iron (FeCl3) significantly increased ferritin formation in Caco-2 and HepG2 cells by 40 and 35 %, respectively, in comparison with iron alone treated cells; this effect was negated in the Caco-2 cell line by phytates and polyphenols at 1:5 and 1:1 iron:inhibitor molar ratios, respectively. Fructose treatment alone did not significantly increase ferritin formation in either cell line. Fructose combined with FeCl3 in a pH 7 water-based matrix significantly increased ferrozine-chelatable ferrous iron levels by 320 % in comparison with FeCl3 alone. Two liquid ferrous iron supplements with added fructose had significantly higher ferritin compared with dissolved ferrous sulphate tablets; Spatone Appleâ, the supplement that had the highest fructose to iron molar ratio (62:1), had the highest iron bioavailability with ferritin levels 610 % higher compared with ferrous sulphate alone, although it is important to note that it also had the highest concentration of ascorbic acid. Fructose added to ascorbic acid and FeCl3 in a water-based matrix had an additive effect on ferritin formation in Caco-2 cells, significantly increasing ferritin two-fold compared with FeCl3 and ascorbic acid alone. A high-fructose containing sweet potato (SP) infant complementary food with 240 % more fructose compared with a low fructose SP food had significantly higher ferritin levels by 30 %, but ferritin was still relatively low compared to a commercial weaning food (50 % less), possibly secondary to high levels of phytates and polyphenols in the SP-based foods. Lastly, a mixture of exogenous FOS&GOS prebiotics added to Young Child Formulae (YCF, milk-based products for toddlers) increased ferritin formation by approximately 25%, and eliminated significant differences in ferritin levels in comparison to YCF with manufacturer added FOS&GOS. Gene and protein expression analysis did not support the hypothesis that the observed increase in fructose-induced ferritin was due to changes to iron transporter or homeostasis molecules. Caco-2 and HepG2 cell gene and protein analysis demonstrated significant changes in pathways related to CRC, HCC and NAFLD. Key significant findings of iron and fructose cell treatments were: 1.5 fold or greater changes in HepG2 gene expression of SMADs 2 and 3, STAT3 and NF-κb -- signalling proteins implicated in development of inflammatory liver disease; increased HepG2 mRNA expression of cell cycle related genes, Cyclin D1 and Cyclin D2, and the proto-oncogene Skp2; decreased mRNA expression of HNF4A, a key liver transcription factor, but with increased HNF4A protein expression; increased HepG2 mRNA and protein expression of the “cancer chaperone” Heat Shock Protein 90; and significantly decreased mRNA expression of the tumour suppressor gene APC by 1.3 fold in iron alone treated Caco-2 cells. In conclusion, fructose, HFCS, and a mixture of prebiotics increased iron bioavailability as assessed by ferritin formation in an in vitro intestinal cell model. The observed effects were negated by phyates and polyphenols in a water-based matrix, and also in a complex food matrix (sweet potato-based) containing high levels of these inhibitors, indicating that these carbohydrates would not increase gut iron uptake when eaten as part of a mixed diet containing polyphenols and phytates. Iron/mineral supplements with added fructose and ascorbic acid in a water-based matrix were associated with higher available iron in comparison with ferrous sulphate alone; fructose had an additive effect with ascorbic acid suggesting that iron supplement bioavailability could be improved with the addition of fructose. In a milk-based food matrix added prebiotics FOS&GOS significantly improved available iron suggesting that a mixture of FOS&GOS prebiotics could improve the nutritional benefits of YCF in relation to iron deficiency. Fructose added to iron solutions also increased ferritin in an in vitro hepatocyte cell model. Fructose-induced ferritin increases did not appear to be secondary to altered expression of iron homeostasis molecules, but rather to changed iron oxidation state to the more bioavailable ferrous form. Changes observed in genes and proteins associated with CRC, HCC and NAFLD with iron and fructose treatments related to multiple pathways implicated in these diseases, and require further study. All of the above were obtained in vitro, therefore in vivo confirmation of these findings is required for further evaluation of their impact on human health and disease

Sugars Increase Non-Heme Iron Bioavailability in Human Epithelial Intestinal and Liver Cells

Previous studies have suggested that sugars enhance iron bioavailability, possibly through either chelation or altering the oxidation state of the metal, however, results have been inconclusive. Sugar intake in the last 20 years has increased dramatically, and iron status disorders are significant public health problems worldwide; therefore understanding the nutritional implications of iron-sugar interactions is particularly relevant. In this study we measured the effects of sugars on non-heme iron bioavailability in human intestinal Caco-2 cells and HepG2 hepatoma cells using ferritin formation as a surrogate marker for iron uptake. The effect of sugars on iron oxidation state was examined by measuring ferrous iron formation in different sugar-iron solutions with a ferrozine-based assay. Fructose significantly increased iron-induced ferritin formation in both Caco-2 and HepG2 cells. In addition, high-fructose corn syrup (HFCS-55) increased Caco-2 cell iron-induced ferritin; these effects were negated by the addition of either tannic acid or phytic acid. Fructose combined with FeCl3 increased ferrozine-chelatable ferrous iron levels by approximately 300%. In conclusion, fructose increases iron bioavailability in human intestinal Caco-2 and HepG2 cells. Given the large amount of simple and rapidly digestible sugars in the modern diet their effects on iron bioavailability may have important patho-physiological consequences. Further studies are warranted to characterize these interactions

Action of iron and fructose on gene expression in human liver cells

Introduction: Evidence suggests that iron and fructose may play a role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD) – the most common liver disorder in the developed world. Furthermore, there is evidence that chemical interactions between iron and fructose generate hepatotoxic metabolites that could contribute to NAFLD progression; however, other studies have shown that fructose sequesters iron and is protective against iron-induced oxidative stress. Previously we showed fructose increased liver iron uptake. The aim of this study was to investigate the effects of iron and fructose - alone and in combination - on gene expression in human liver cells. Methods: HepG2 hepatoma cells were treated with 1μM ferric ammonium citrate (FAC) and 15 mM fructose for 24 hours, and then harvested for RNA. Gene expression was assessed using Affymetrix Genechip Human Genome microarray and subsequent bioinformatic analysis using GeneGo Metacore software. Results: Treatment of cells with fructose and FAC together decreased the expression of signalling proteins in two major pathways implicated in development of inflammatory liver disease: transforming growth factor β (TGF β) - as evidenced by lowered gene expression of SMAD2 and SMAD3 - and STAT3/NF-κB. Fructose treatment alone activated complement pathways with increased expression of C3, C5 convertase and the membrane attack complex. Discussion and Conclusion: Our results suggest that hepatic fructose-iron interactions are anti-inflammatory, possibly via fructose induced iron sequestration; fructose alone, however, may cause inflammation by increasing activity of the innate immune system. The liver is continually exposed to both iron and fructose via the portal circulation system. Further research is essential to assess the roles of iron and fructose metabolism in the development and progression of NAFLD

Effect of high-fructose corn syrup (HFCS) digests on iron-induced ferritin.

<p>Measurement of Caco-2 cell ferritin formation from digests of Fe and fructose (Fructose+Fe), or Fe and HFCS-55 (HFCS+Fe) at an iron:fructose ratio of ≈ 1:2000. Equal amounts of iron (25 µg) were combined with fructose solutions (1.0 mL) and subjected to the Caco-2 in vitro digestion process. Digests with HFCS alone and no added Fe (No Food Digest) were used as negative controls; digests with Fe alone (Fe) and Fe plus ascorbic acid (Fe + AA) were used as reference controls and positive controls, respectively. Values are means of data normalized to 10 ng of ferritin/mg protein in the reference control (Fe) ± SEM, n ≥ 18. Based on an ANOVA (p<0.0001) with Tukey’s multiple comparisons test post-hoc analysis done on an all-pairwise basis, bar values with no letters in common are significantly different (p ≤ 0.010).</p

HepG2 iron-induced ferritin in response to carbohydrate treatments.

<p>Measurement of HepG2 cell ferritin formation following treatment for 24 µmol/L ferric ammonium citrate (FAC) and one of the following: 15 mmol/L glucose (Glucose+FAC); 15 mmol/L glucose and 15 mmol/L fructose (Fructose+Glucose+FAC); 15 mmol/L fructose (Fructose+FAC). Cells treated with MEM alone (MEM), or fructose alone (Fructose Only), without the addition of FAC, were used as negative controls. Cells treated with 0.1 mmol/L ascorbate and 1 µmol/L FAC were used as positive controls. Values are means of data normalized to 400 ng of ferritin/mg protein in the reference control (MEM+FAC) ± SEM, n(MEM) = 4, n(Fructose Only) = 6, all other n ≥ 12. Based on an ANOVA (p<0.0001) with Tukey’s multiple comparisons test post-hoc analysis done on an all-pairwise basis, bar values with no letters in common are significantly different (p ≤ 0.010).</p