BackgroundEmerging evidence indicates that there is an association between vitamin D and obesity. The aim of this study was to investigate whether the level of serum 25-hydroxyvitamin D3 [25(OH)D3] in the elderly is influenced by parameters of anthropometry and body composition independent of potential confounding lifestyle factors and the level of serum intact parathyroid hormone (iPTH).MethodsCross-sectional data of 131 independently living participants (90 women, 41 men; aged 66–96 years) of the longitudinal study on nutrition and health status in senior citizens of Giessen, Germany were analysed. Concentrations of 25(OH)D3 and iPTH were ascertained by an electrochemiluminescence immunoassay. Body composition was measured by a bioelectrical impedance analysis. We performed univariate and multiple regression analyses to examine the influence of body composition on 25(OH)D3 with adjustments for age, iPTH and lifestyle factors.ResultsIn univariate regression analyses, 25(OH)D3 was associated with body mass index (BMI), hip circumference and total body fat (TBF) in women, but not in men. Using multiple regression analyses, TBF was shown to be a negative predictor of 25(OH)D3 levels in women even after controlling for age, lifestyle and iPTH (ß = −0.247; P = 0.016), whereas the associations between BMI, hip circumference and 25(OH)D3 lost statistical significance after adjusting for iPTH. In men, 25(OH)D3 was not affected by anthropometric or body composition variables.ConclusionsThe results indicate that 25(OH)D3 levels are affected by TBF, especially in elderly women, independent of lifestyle factors and iPTH.

Objectives To investigate tooth wear in young adults, intraoral scanning was used for digital monitoring of the mandibular first molar over 12 months. A possible influence of aetiological factors obtained by a questionnaire on tooth wear was investigated. Materials and methods A total of 109 participants (mean age at the start of the study: 21.0 ± 2.2 years) were included in this clinical study. At baseline (T0), an intraoral scan (Trios 3, 3Shape) of the study tooth (FDI # 36 or #46) was conducted. After a mean observation period of 373 ± 19 days, a second intraoral scan (T1, n = 94) of the same tooth as at T0 was performed and standard tessellation language datasets were superimposed with 3D analysis software (GOM Inspect). The occlusal surface of the study tooth was divided into 7 areas (5 cusps, 2 ridges) and maximum vertical substance loss was measured between T0 and T1 (n = 91). Three types of tooth wear were defined: cupping (C), facet (F) and combined cupping-facet (CF). Furthermore, a questionnaire on aetiological factors, such as dietary behaviour, was filled out at T0. Data were analysed with non-parametric tests (p < 0.05). Results Only one study tooth exhibited no tooth wear at T0, whereas 3 teeth showed C, 47 teeth F and 40 teeth CF. A progression of vertical substance loss for all three types was shown. Most affected were the mesiobuccal cusps (43, 38/47 µm; median, 95%CI) followed by distobuccal (36, 33/39 µm), mesiolingual (35, 26/40 µm), distolingual (34, 27/36 µm) and distal (31, 25/34 µm). On mesial and distal ridges, only F was detected with the lowest vertical substance loss of all areas (mesial ridge: 0, 0/0 µm; distal ridge: 0, 0/0 µm). An association between aetiological factors and loss values could not be shown. Conclusions All study teeth showed clear signs of wear, and after only 1 year, further substance loss was detectable. This result is of significance for young adults. Clinical relevance Since data of young adults regarding tooth wear are scarce, the results give a first idea of the amount of vertical loss per year and its relation to aetiological factors such as dietary behaviour. Therefore, further studies over a longer observation period are highly recommended.

The lower vitamin C plasma concentrations in elderly men compared with elderly women can partly be attributed to a volumetric dilution effect due to differences in fat-free mass Abstract Women show higher vitamin C plasma concentrations than men, but the reasons for this observation still require elucidation. The objective of the present study was to investigate whether sex differences in vitamin C plasma concentrations are present in elderly subjects and whether these differences are due to sex-specific lifestyles, total antioxidant status (TAOS) and/or body composition. Fasting plasma concentrations of vitamin C were assessed by photometric detection in a cross-sectional study of 181 women and eighty-nine men aged 62 -92 years. Body composition was determined by bioelectrical impedance analysis. Vitamin C intake was assessed with a 3 d estimated dietary record. Stepwise multiple regression analyses were performed to investigate whether sex is an independent predictor of vitamin C plasma concentrations by controlling for age, vitamin C intake, lifestyle factors, TAOS and body composition. Women showed higher vitamin C plasma concentrations than men (76 v. 62 mmol/l, P, 0·0001). In the multiple regression analysis, male sex was a negative predictor of vitamin C plasma concentrations (b ¼ 2 0·214), as long as absolute fat-free mass (FFM) was not considered as a confounder. When absolute FFM was included, sex was no longer a predictor of vitamin C plasma concentrations, whereas absolute FFM (b ¼ 20·216), physical activity level (b ¼ 0·165), intake of vitamin C supplements (b ¼ 0·164), age (b ¼ 0·147) and smoking (b ¼ 20·125) affected vitamin C plasma concentrations. The results indicate that a higher absolute FFM, and thus a higher distribution volume of vitamin C, contributes to lower vitamin C plasma concentrations in men than women.

Objective: Although emerging evidence indicates an association between vitamin D and serum lipids, the data are still inconsistent. The purpose of the present study was to investigate whether 25-hydroxycholecalciferol (25-hydroxyvitamin D 3 ; 25(OH)D 3 ) or intact parathyroid hormone (iPTH) was independently related to serum lipids in elderly women and men. Design: Cross-sectional study. Fasting serum levels of 25(OH)D 3 , iPTH, TAG, total cholesterol (TC), HDL cholesterol (HDL-C) and LDL cholesterol (LDL-C) were assessed. Body composition was measured by bioelectrical impedance analysis. Lifestyle factors, such as nutrient intake, time spent outdoors, physical activity, smoking, supplement intake and medication, were assessed by questionnaires. Multiple regression analyses were performed to examine associations of 25(OH)D 3 and iPTH with serum lipids. Setting: Giessen, Germany. 25-Hydroxycholecaliferol Parathyroid hormone Serum lipids ElderlyAccumulating epidemiological data indicate that vitamin D deficiency may be accompanied by susceptibility for chronic diseases (1) . Recently, a low vitamin D status has been linked to increased serum levels of TAG, total cholesterol (TC) and LDL cholesterol (LDL-C), as well as low concentrations of HDL cholesterol (HDL-C) (2)(3)(4)(5)(6)(7)(8) . Parathyroid hormone (PTH), which increases in the presence of vitamin D insufficiency, was also linked to serum lipids (9) . However, the results are inconsistent and associations often vanished after controlling for confounding variables (5,6,8) .The question arises whether the assumed associations between serum lipids and vitamin D and PTH are independent from other cardiovascular risk factors like obesity, which has been associated with elevated serum lipids (10) and may also interfere with the vitamin D endocrine system (11) . In addition, the associations may differ by sex considering the differences in body composition and serum lipid levels between women and men. Previous studies were mostly performed on ambulatory patients and/or vitamin Ddeficient, middle-aged or overweight and obese individuals and often without adjustments for potential confounders, such as the association between vitamin D and PTH, body composition, medical conditions and/or lifestyle factors, including sun exposure, physical activity and habitual diet (4)(5)(6)(7)9,(12)(13)(14)(15) .As dyslipidaemia is an important CVD risk factor and an established component of the metabolic syndrome, treatment and prevention strategies are of particular importance (16) . This applies especially to elderly people, who are at risk of developing dyslipidaemia. Moreover, an advanced age is linked to vitamin D deficiency because of age-related declines in endogenous vitamin D synthesis, sun exposure

BackgroundConsidering the suggested link between vitamin D insufficiency and several chronic diseases, attention should be given to approaches for improving vitamin D status. Elderly subjects are regarded as a high-risk group for developing an insufficient vitamin D status. Socioeconomic, dietary, lifestyle and environmental factors are considered as influencing factors, whereupon sex differences in predictors of vitamin D status are rarely investigated. The purpose of this study is to identify the main predictors of serum 25-hydroxyvitamin D3 [25(OH)D3] concentrations in elderly subjects by taking into account potential sex differences.MethodsThis is a cross-sectional study in 162 independently living German elderly aged 66 to 96 years. Serum 25(OH)D3 concentrations were assessed by an electrochemiluminescence immunoassay. Multiple regression analyses were performed to identify predictors of 25(OH)D3 concentrations stratified by sex.ResultsMedian 25(OH)D3 concentration was 64 nmol/L and none of the subjects had 25(OH)D3 concentrations < 25 nmol/L. In women, intact parathyroid hormone (iPTH) (β = -0.323), % total body fat (β = -0.208), time spent outdoors (β = 0.328), month of blood sampling (β = 0.229) and intake of vitamin D supplements (β = 0.172) were the predominant predictors of 25(OH)D3, whereas in men, iPTH (β = -0.254), smoking (β = -0.282), physical activity (β = 0.336) and monthly household net income (β = 0.302) predicted 25(OH)D3 concentrations. The final regression models accounted for 30% and 32% of the variance in 25(OH)D3 concentrations in women and men, respectively.ConclusionThe findings indicate that 25(OH)D3 concentrations are influenced by body composition, month of blood sampling, economic factors, lifestyle, supplement intake and iPTH, but may not be associated with age, sex, dietary factors, kidney function and presence of selected chronic diseases in community-dwelling elderly. Furthermore, our results provide evidence for sex-specific determinants of the vitamin D status, which ought to be considered for preventive strategies.

BackgroundElderly subjects are at risk of insufficient vitamin D status mainly because of diminished capacity for cutaneous vitamin D synthesis. In cases of insufficient endogenous production, vitamin D status depends on vitamin D intake.ObjectiveThe purpose of this study is to identify the main food sources of vitamin D in elderly subjects and to analyse whether contributing food sources differ by sex, age, vitamin D status, body mass index (BMI), or household income. In addition, we analysed the factors that influence dietary vitamin D intake in the elderly.Design and subjectsThis is a cross-sectional study in 235 independently living German elderly aged 66–96 years (BMI=27±4 kg/m2). Vitamin D intake was assessed by a 3-day estimated dietary record.ResultsThe main sources of dietary vitamin D were fish/fish products followed by eggs, fats/oils, bread/bakery products, and milk/dairy products. Differences in contributing food groups by sex, age, vitamin D status, and BMI were not found. Fish contributed more to vitamin D intake in subjects with a household income of <1,500 €/month compared to subjects with higher income. In multiple regression analysis, fat intake and frequency of fish consumption were positive determinants of dietary vitamin D intake, whereas household income and percentage total body fat negatively affected vitamin D intake. Other parameters, including age, sex, physical activity, smoking, intake of energy, milk, eggs and alcohol, showed no significant association with vitamin D intake.ConclusionLow habitual dietary vitamin D intake does not affect vitamin D status in summer, and fish is the major contributor to vitamin D intake independent of sex, age, vitamin D status, BMI, and the income of subjects.

Background Riboflavin is required to generate the active form of vitamin B-6 (pyridoxal 5′-phosphate; PLP) in tissues, but the relevance of this metabolic interaction for nutritional status of vitamin B-6 is unclear because riboflavin biomarkers are rarely measured in human studies. Objectives The purpose of this study was to identify the determinants of biomarkers of vitamin B-6 and riboflavin status and to examine the relationship between these nutrients in healthy adults. Methods Multiple linear regression was performed on observational data in 407 healthy adults aged 18–92 y who did not use B-vitamin supplements. Vitamin B-6 status was assessed by plasma PLP concentrations and erythrocyte glutathione reductase activation coefficient (EGRac) was used as a functional indicator of riboflavin status. Results Dietary intakes of vitamin B-6 and riboflavin were below the average requirements in 10% and 29% of participants, respectively. Suboptimal status of vitamin B-6 (PLP ≤30.0 nmol/L) was more prevalent in adults aged ≥60 y than in younger participants (i.e., 14% compared with 5%), whereas a high proportion (i.e., overall 37%) of both age groups had deficient riboflavin status (EGRac ≥1.40). In multiple regression analysis, EGRac (P = 0.019) was a significant determinant of plasma PLP, along with dietary vitamin B-6 intake (P = 0.003), age (P &lt; 0.001), BMI (kg/m2) (P = 0.031), and methylenetetrahydrofolate reductase gene (MTHFR) genotype (P &lt; 0.001). Significant determinants of EGRac were dietary riboflavin intake (P &lt; 0.001), age (P &lt; 0.001) and MTHFR genotype (P = 0.020). Plasma PLP showed a stepwise decrease across riboflavin status categories from optimal (EGRac ≤1.26) to low (EGRac 1.27–1.39) to deficient status (P = 0.001), independent of dietary vitamin B-6 intake. Conclusions The findings are consistent with the known metabolic dependency of vitamin B-6 on riboflavin status and indicate that riboflavin may be the limiting nutrient, particularly in older people, for maintaining adequate vitamin B-6 status.

Although the interrelation between vitamins C and E has been demonstrated on an experimental level, its impact on biomarkers in community-dwelling subjects along the trajectory of ageing has not yet been shown. The present longitudinal study investigates the determinants and interrelation of vitamins C and E plasma concentrations in 399 subjects aged ≥60 years with a median follow-up time of 12 years. Linear mixed-effects models were used to analyze the influence of age, sex, body composition, dietary intake, physical activity, smoking and supplement/drug use on plasma vitamin C, plasma α-tocopherol and α-tocopherol/total cholesterol ratio. At baseline, median plasma concentrations of vitamin C and α-tocopherol were 74 and 35 µmol/L. Absolute fat-free mass, physical activity, use of supplements, and plasma α-tocopherol were main determinants of plasma vitamin C in the course of ageing. For the α-tocopherol/total cholesterol ratio, age, use of supplements, use of lipid-modifying drugs, and plasma vitamin C were main determinants. The results reveal a stable positive interrelation between plasma concentrations of vitamins C and E along the trajectory of ageing independent of the other identified determinants. The possible regulatory mechanisms that could explain this robust positive interrelation remain to be elucidated.