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The objective of this study was to investigate the influence of a high-sodium, high-protein diet on bone metabolism in postmenopausal women (aged 49-60 y) stratified by hormone replacement therapy (HRT) use. In a crossover trial, 18 women (n=8 HRT users (+HRT) and n=10 nonusers (-HRT)) were randomly assigned to a diet high in protein (90 g/day) and sodium (180 mmol/day) (calciuric diet) or a diet moderate in protein (70 g/day) and low in sodium (65 mmol/day) for 4 weeks followed by crossover to alternative dietary regimen for a further 4 weeks. The calciuric diet significantly (P [less than] 0.05) increased urinary sodium, calcium and nitrogen in both groups. While the calciuric diet increased urinary N-telopeptide crosslinks of collagen (by [similar]25%, P=0.003) in the -HRT group, it had no effect in the +HRT group. It appears that postmenopausal HRT use attenuates the increase in a marker of bone resorption associated with a calciuric diet. European Journal of Clinical Nutrition (2004) 58, 1436-1439. doi: 10.1038/sj.ejcn.1601983 Published online 21 April 2004 Keywords: sodium, protein, bone metabolism, HRT, postmenopausal women, Author(s): M Harrington [1]; T Bennett [1]; J Jakobsen [3]; L Ovesen [3]; C Brot [3]; A Flynn [1]; KD Cashman [1, 2] Introduction We have recently shown that a [...]

Background/objectives: Data from human studies that have investigated the association between vitamin D status and cognitive function in elderly adults are conflicting. The objective of this study was to assess vitamin D status (reflected by serum 25-hydroxyvitamin D (25(OH)D)) in older European subjects (n=387; aged 55-87 years) and examine its association with measures of cognitive function., Subjects/methods: Serum 25(OH)D was assessed using enzyme-linked immunosorbent assay, whereas measures of cognitive function were assessed using a comprehensive Cambridge Neuropsychological Testing Automated Battery (CANTAB)., Results: In all, 12, 36 and 64% of subjects had serum 25(OH)D concentrations <30, <50 and <80 nmol/l, respectively, throughout the year. Serum 25(OH)D was significantly and inversely correlated with four assessments within the spatial working memory (SWM) test parameter (SWM between errors (r=-0.166; P=0.003); SWM between errors 8 boxes (r=-0.134; P=0.038); SWM strategy (r=-0.246; P<0.0001); and SWM total errors (r=-0.174; P<0.003)). When subjects were stratified on the basis of tertiles (T) of serum 25(OH)D (<47.6 (T(1)); 47.6-85.8 (T(2)); and >85.8 (T(3)) nmol/l), fewer errors in SWM test scores occurred in subjects in the third T when compared with the first T (P<0.05-0.084). Stratification by sex showed that these differences between tertiles strengthened (P<0.001-0.043) in the females, but the differences were not significant (P>0.6) in males., Conclusions: Vitamin D insufficiency, but not deficiency, is widespread in the older population of several European countries. Low vitamin D status was associated with a reduced capacity for SWM, particularly in women.

Objective: To determine vitamin D and bone status in adolescent girls, pre-menopausal women and men of Pakistani origin, to single out determinants of vitamin D status and to determine the association between vitamin D status, bone metabolism and bone status., Subjects/methods: Cross-sectional study, Copenhagen (55 degrees N), January-November. Serum 25-hydroxyvitamin D (S-25OHD), serum intact parathyroid hormone (S-iPTH), bone turnover markers and whole body and lumbar spine bone mineral density were measured. Sun, smoking and clothing habits, age, body mass index (BMI), and vitamin D and calcium from food and from supplements were recorded. Thirty-seven girls (median age, range: 12.2 years, 10.1-14.7), 115 women (36.2 years, 18.1-52.7) and 95 men (38.3 years, 17.9-63.5) of Pakistani origin (immigrants or descendants with Pakistani parents) took part in the study., Results: Median concentration of S-25OHD was 10.9, 12.0 and 20.7 nmol/l for girls, women and men, respectively. Forty-seven per cent of the girls, 37% of the women and 24% of the men had elevated S-iPTH, and there was a negative relationship between S-iPTH and S-25OHD. Use of vitamin D-containing supplements had a positive association with S-25OHD for men (P=0.04) and women (P=0.0008). Twenty-one per cent of the women and 34% of the men had osteopenia. Neither S-25OHD nor S-iPTH was associated with lumbar spine or whole body bone mineral content., Conclusions: Severely low vitamin D status and elevated S-iPTH is common among Pakistani immigrants in Denmark. The low vitamin D status is not associated with bone markers or bone mass among relatively young Pakistanis.

Objective: To investigate determinants (pathophysiologic and physiologic, behavioural and lifestyle) of vitamin D status in Irish Crohn's disease (CD) patients., Design: A cross-sectional observational study., Setting: Cork City, Ireland (52 degrees N)., Subjects: Crohn's Disease patients (n=58; mean age 38.1 years) were recruited from Cork University Hospital., Results: Fifty and nineteen percent of Irish CD patients were vitamin D deficient (defined by serum 25 hydroxyvitamin (OH) D levels <50 nmol/l) during winter and summer, respectively. Multiple regression analysis showed that summer-time serum 25 (OH) D levels were positively associated with use of vitamin D supplements (P=0.033) and negatively associated with smoking (P=0.006) and being male (P=0.063). During winter-time, use of vitamin D supplements (P=0.041) and sun habits (P=0.066) were positively associated, whereas small intestinal involvement (P=0.005) and body mass index (BMI) (P=0.083) were negatively associated with serum 25 (OH) D levels. There was no significant association between other non-pathophysiologic (age, dietary calcium or vitamin D) or pathophysiologic factors (steroid use, resection), and serum 25 (OH) D levels, at either season. Approximately 41 and 60% of the total variation in summer- and winter-time serum 25 (OH) D, respectively, was explained by this model., Conclusion: A high proportion of Irish CD patents had some level of vitamin D deficiency (<50 nmol/l) during late-wintertime. Use of regular low-dose supplemental vitamin D, particularly by patients with small intestinal involvement, cessation of smoking and adequate, but responsible, exposure to summer sunlight as well as maintaining BMI in the normal range could help maintain adequate vitamin D levels during wintertime.

Objective: To investigate the relationship between indices of zinc nutritive status and biochemical markers of bone turnover in older adult European subjects., Design: Use of baseline data from a multicentre prospective zinc intervention (ZENITH) study., Setting: Centres in France, Italy and Northern Ireland., Participants: A total of 387 healthy adults, aged 55-87 y., Methods: Zinc intake was assessed by 4-day recall records. Circulating and urinary biochemical zinc status measures were assessed by atomic absorption spectrophometry. Serum bone-specific alkaline phosphatase and osteocalcin were assessed by ELISA and urinary pyridinoline (Pyr) and deoxypyridinoline (Dpyr) by HPLC., Results: Zinc intake was negatively correlated with urinary Pyr and Dpyr (r = -0.298 and -0.304, respectively; P < 0.0001), but was not correlated with bone formation markers. There was a tendency for serum zinc to be negatively correlated with urinary Dpyr (r = -0.211; P = 0.080). Erythrocyte zinc was negatively correlated with serum osteocalcin (r = -0.090; P < 0.0001). None of the other correlations were significant. After adjustment for confounder (age, gender and research centre) the only significant association that remained was between serum osteocalcin and erythrocyte zinc (beta = -0.124; P = 0.011)., Conclusions: There was some, albeit inconsistent, evidence of a relationship between zinc nutritive status and bone turnover in the older adult participants of the ZENITH study.

Zinc is known to be essential for a great number of biochemical activities and physiological and cognitive functions. The objective of Zenith study was to investigate the effects of Zn, as a nutritional supplement, on psychological and behavioural factors and on surrogate markers that are indicative of trends towards better health in order to evaluate the need for dietary recommendations specific to the studied population. We report in this paper the summary of baseline results obtained before Zn supplementation.

Background: Adjustments in intestinal absorption and losses of zinc (Zn) are thought to maintain Zn homeostasis when dietary intake levels are altered. Zn status may also influence efficiency of intestinal Zn absorption., Objectives: To determine the impact of dietary intake and status of some micronutrients on Zn absorption in late middle-aged men., Design and Participants: Dietary intake and status of Zn, Cu, Fe, vitamin A, C and fibre, and absorption of Zn were measured in 48 men, aged 58-68 y, confined to a metabolic unit and consuming a typical French diet. Dietary intake was estimated using 4-day food-intake records (including the weekend) and the GENI program. To assess Zn status, serum, erythrocyte, urine Zn levels and serum alkaline phosphatase activity were determined. Zn absorption was determined using the isotope double-labelling method. Zn stable isotopic ratios were measured in plasma samples collected before and 48 h after isotope administration using ICP/MS., Results: Zn intake within the group of men varied from 5.7 to 20.5 mg/day and averaged 12.9 mg/day. Serum Zn level varied from 10 to 18 micromol/l and averaged 12.9 micromol/l. Zn absorption varied from 12 to 46% and averaged 29.7%. Zn absorption was not significantly (P > 0.05) correlated with Zn intake or with any of the Zn status parameters. Zn absorption was only slightly negatively correlated with serum and erythrocyte Zn levels and with serum Fe and ferritin levels in this study., Conclusion: Zn dietary intake and Zn absorption were satisfactory and led to an adequate Zn status in this population.

The elderly are at nutritional risk as a result of multiple physiological, social, psychological, and economic factors. Physiological functions naturally decline with age, which may influence absorption and metabolism. Social and economic conditions can adversely affect dietary choices and eating patterns. However, at the same time, the nutrient needs of the elderly for certain nutrient (such as vitamins, minerals, proteins) is higher than for younger adults. This article reviews the importance of zinc (Zn) in elderly people, particularly for behavioural and mental function, micronutrient status, immune and antioxidant system, and bone metabolism.

Objective: To determine the vitamin D status (serum 25-hydroxyvitamin D; S-25OHD) in adolescent girls and elderly community-dwelling women living in four countries of northern Europe and to explain differences in S-25OHD concentrations between and within the countries., Design: A cross-sectional observational study conducted in a standardised way during February-March. S-25OHD was analysed by high-performance liquid chromatography. Vitamin D and calcium intake was calculated using a standardised food composition database., Setting: Denmark, Finland, Ireland, and Poland., Subjects: A total of 199 girls (mean (s.d.) age 12.6 (0.5) y) and 221 women (mean (s.d.) age 71.8 (1.4) y)., Results: The median (inter quartiles) concentration of S-25OHD was 29.4 (20.3, 38.3) nmol/l for the girls and 40.7 (28.0, 54.2) nmol/l for the women. S-25OHD below 25 nmol/l was found in 37% of the girls and 17% of the women, and S-25OHD below 50 nmol/l was found in 92% of the girls and 37% of the women. Positive significant determinants for S-25OHD in girls were use of vitamin D supplements, and in women sun habits, dietary vitamin D intake, use of vitamin D and calcium supplements. Body mass index and smoking were negative determinants in women. For women predictors could explain the differences between countries (P(country) = 0.09, R(2) = 0.39), but for girls the difference remained significant even after including predictors (P(country) = 0.03, R(2) = 0.15)., Conclusion: Vitamin D status is low in northern Europe during winter. More than one-third of the adolescent girls have vitamin D status below 25 nmol/l and almost all are below 50 nmol/l. Two-thirds of the elderly community-dwelling women have vitamin D status below 50 nmol/l. Use of vitamin D supplements is a significant positive determinant for S-25OHD for both girls and women (P = 0.001)., Sponsorship: The European Fifth Framework Programme (Contract No. QLK1-CT-2000-00623).

Introduction: Conjugated linoleic acid (CLA) has been shown to positively influence calcium and bone metabolism in experimental animals and cells in culture, but there are limited human data available., Objective: To investigate the effect of CLA supplementation on biomarkers of calcium and bone metabolism in healthy adult males., Design: The study consisted of a double-blind, placebo-controlled trial in which 60 healthy adult males (aged 39-64 y) were randomly assigned to receive daily either 3.0 g CLA isomer blend (50:50% cis-9,trans-11:trans-10,cis-12 isomers) or a palm/bean oil blend (placebo) for 8 weeks. Urine and blood samples were collected at weeks 0 and 8 and were analysed for biomarkers of calcium and bone metabolism., Results: Supplementation with CLA or placebo for 8 weeks had no significant effects on markers of bone formation (serum osteocalcin and bone-specific alkaline phosphatase) or bone resorption (serum C-telopeptide-related fraction of type 1 collagen degradation products, urinary N-telopeptide-related fraction of type 1 collagen degradation products, urinary pyridinoline and deoxypyridinoline), or on serum or urinary calcium levels. Baseline levels of these biochemical parameters were similar in both groups of subjects. While the placebo had no effect, CLA supplementation resulted in a three-fold increase (P<0.00001) in cis-9,trans-11 CLA isomer in total plasma lipids., Conclusion: Under the conditions tested in this double-blind, placebo-controlled trial in adult men, a CLA supplement of mixed isomers did not affect markers of calcium or bone metabolism. Further investigation of the effects of CLA on calcium and bone metabolism in other gender- and age-groups is warranted.

Objective: The objective of this study was to assess vitamin D status during late-summer and late-winter/early-spring in postmenopausal Irish women, and whether it was influenced by vitamin D-containing supplement use., Design: A longitudinal observational study., Setting: Cork City, Ireland (51 degrees north)., Subjects: A total of 59 apparently healthy, free-living, postmenopausal women aged between 51 and 69 y were sampled during February/March 2002. Of these, 48 and 47 returned during August/September 2002 and February/March 2003, respectively. None of the women were suffering from any medical condition likely to affect vitamin D status. Fasting serums were collected and analysed for 25-hydroxyvitamin D (25 (OH) D) and parathyroid hormone (PTH) by enzyme immunoassays., Results: Mean daily intake of vitamin D was 3.2 microg from food sources alone and 5.8 microg when vitamin D-containing supplements were included (P<0.01). Serum 25 (OH) D was significantly lower (P<0.001) during February/March 2002 than both August/September 2002 and February/March 2003. Serum 25 (OH) D was also significantly higher (P < or = 0.05) in women who were vitamin D-containing supplement users than nonusers during all three sampling points. Between 17 and 36% of women had inadequate vitamin D status (defined as serum 25 (OH) D <40 nmol/l) during late-winter, but only 4% had inadequate vitamin D status during late-summer. Serum 25 (OH) D was inversely related to serum PTH (r = -0.33; P = 0.028)., Conclusion: Suboptimal vitamin D status is common in postmenopausal Irish women during winter. Vitamin D supplementation is associated with improved vitamin D status, even during summertime.

Objective: To estimate vitamin D intakes in a representative sample of Irish adults and to assess the contribution of foods to these intake estimates., Design: Vitamin D intakes in 1379, 18-64-y-old adults from the North/South Ireland Food Consumption Survey were estimated using a combination of new analytical data for vitamin D in foods, determined by HPLC, and used to revise recipe calculations, together with existing data from McCance and Widdowson's The Composition of Foods, 5th Edition plus supplements., Results: The total mean daily intake (MDI) of vitamin D (1 microg=40 IU) from all sources was 4.2 microg. The MDI was significantly higher (P<0.001) when the contribution from nutritional supplements was included (4.2 microg) compared with food sources only (3.2 microg). Men had significantly higher intakes (4.4 microg) than women (4.0 microg; P<0.001), which increased significantly (P<0.001) with age in both sexes. Meat/meat products (30.1%), fish/fish products (14.3%) and eggs/egg dishes (9.1%) were the main contributors to vitamin D intake. Supplements contributed 6.8 and 12% to MDI in men and women, respectively. In all, 74% of adults had an MDI of vitamin D that was less than the median (5 microg) of the recommended daily range of 0-10 microg., Conclusion: The findings of this study suggest that a large number of Irish adults have low vitamin D intakes. This, along with emerging evidence of low vitamin D status in at least some population subgroups, suggests that strategies to increase vitamin D intakes, including fortification of food, should be investigated.

Objective: To measure the intake of selenium (Se) and the contribution of different food groups to Se intake in adults aged 18-64 y in Ireland. The adequacy of Se intake in the population is also assessed., Design: Food consumption was estimated using a 7 day food diary for a representative sample (n=1379; men=662, women=717) of 18-64-y-old Irish adults selected randomly from the electoral register. Se intake was estimated using updated tables of food composition., Results: Mean daily Se intakes (+/-s.d.) from all sources (ie food plus supplements), and from food sources alone, for the group of Irish adults aged 18-64 y were 52 (+/-23) and 50 (+/-21) microg, respectively. Mean daily Se intake (from all sources) was significantly higher in men of all ages than women of all ages at levels of 60 and 44 microg, respectively (P<0.001). Meat/meat products (30%), bread and rolls (24%), fish/fish products (approximately 11%), and milk and yoghurt (9%) were the main contributors to mean daily Se intake. Adequacy of Se intake in population groups was estimated as the percentage of the population with mean daily Se intakes that were lower than the average requirement of 40 microg. Using this measure, 45.6% of women and 17.1% of men had inadequate Se intakes., Conclusion: A significant prevalence of inadequate Se intakes was observed in Irish adults. Therefore, it would seem prudent that the Se status of the Irish population be investigated at this time.

Objective: To investigate the effects of increasing Cu intakes, above the usual dietary intake, on biomarkers of bone metabolism in healthy young adult females (aged 21-28 y) over a 4 week period., Design: A double-blind, placebo-controlled randomised repeat crossover Cu supplementation trial., Setting: The study was conducted at the Royal Veterinary and Agricultural University (RVAU), Copenhagen, Denmark., Subjects: Sixteen healthy young adult females aged 20-28 y were recruited from among students at the RVAU., Intervention: During the 4 week intervention periods in this randomised, crossover trial (3x4 weeks with a minimum 3 week wash-out period), each subject received, in addition to their usual diet, either 3 or 6 mg elemental Cu/day as CuSO4 or a matching placebo. On the last 3 days of each dietary period 24 h urines were collected. In addition, blood was collected on the last day of each dietary period., Results: Serum Cu and erythrocyte superoxide dismutase (but not caeruloplasmin protein concentration or activity (putative indices of Cu status)) were significantly increased (P<0.05) after daily Cu supplementation with 3 and 6 mg/day for 4 weeks. Serum osteocalcin (biomarker of bone formation), urinary creatinine (Cr) concentration, urinary pyridinoline (Pyr)/Cr or deoxypyridinoline (Dpyr)/Cr excretion, or daily urinary Pyr or Dpyr excretion (biomarkers of bone resorption) were unaffected by Cu supplementation., Conclusion: Copper supplementation of the usual diet in healthy young adult females, while apparently improving Cu status, had no effect on biochemical markers of bone formation or bone resorption over 4 week periods., Sponsorship: Funding from the European Commission.