Efficacy of high dose phylloquinone in correcting vitamin K deficiency in cystic fibrosis. Effect of vitamin K1 supplementation on vitamin K status in cystic fibrosis patients. Two-year randomized controlled trial of vitamin K1 (phylloquinone) and vitamin D3 plus calcium on the bone health of older women. Effect of vitamin C on common cold: randomized controlled trial. A randomized, controlled trial of quadriceps resistance exercise and vitamin D in frail older people: the Frailty Interventions Trial in Elderly Subjects (FITNESS). Vitamin D supplementation improves neuromuscular function in older people who fall. Randomised double blind placebo controlled trial investigating the effect of calcium and vitamin D supplementation on bone mineral density and bone metabolism in adult patients with cystic fibrosis. Incidence of anticonvulsant osteomalacia and effect of vitamin D: controlled therapeutic trial. The clinical effects of vitamin C supplementation in elderly hospitalised patients with acute respiratory infections.
Subclinical deficiencies of vitamin K are universally present in unsupplemented cystic fibrosis (CF) patients. The dose required to prevent deficiencies cannot be estimated from the existing literature. The aim of this study is determine if a supplemental dose of 1 mg/day or 5 mg/day vitamin K1 per day would normalize vitamin K status in a population of children with cystic fibrosis.
                Fourteen pancreatic insufficient CF children, between the ages of 8 to 18 years old, were randomized to receive either 1 mg/day or 5 mg/day vitamin K1 per day, for one month. Fasting blood tests were done at baseline and after one month of the intervention. The degree of undercarboxylation of osteocalcin (%Glu-OC), and serum vitamin K1, were evaluated by descriptive statistics and nonparametric Wilcoxon matched-pair test and Mann-Whitney U test.
                Of the 50% of subjects who were below the optimal serum vitamin K1 at baseline, all rose into the normal range with supplementation. Supplementation also significantly reduced the overall %Glu-OC from a median of 46.8 to 29.1% (p<0.0003).
                Our results suggest that both 1 mg and 5 mg of vitamin K1, given over a one-month period in pancreatic insufficient pediatric cystic fibrosis patients improve vitamin K status. Patients with cystic fibrosis are at risk for impaired vitamin K status due to fat malabsorption from pancreatic insufficiency. This study was designed to assess vitamin K status and measure the effect of vitamin K1 supplementation in cystic fibrosis patients.
                Eighteen outpatients participated in a crossover study to determine the effect of vitamin K1 (phylloquinone) supplementation. After obtaining initial data, each subject was randomly assigned to either a 4-week study treatment of 5 mg oral vitamin K1 supplementation per week, or no supplementation and then crossed over to the other treatment for a second 4 week period. Plasma, serum and urine samples were collected and analyzed pre-study and at the end of each study period.
                The mean concentration of plasma vitamin K1 for the supplemented group was significantly higher than the unsupplemented group, [0.34 nmol/L and 0.21 nmol/L, respectively (p < 0.05)]. The percent of undercarboxylated osteocalcin increased on supplementation from 17% to 31%, (p < 0.005). Prothrombin induced in vitamin K absence (PIVKA-II) increased on supplementation from 5 ng/mL to 22 ng/mL, (p < 0.005). The ratio of urinary gamma-carboxyglutamic acid/creatinine was similar for both study periods.
                In contrast to other studies in cystic fibrosis, this study demonstrated a need for vitamin K1 supplementation. The carboxylation state of osteocalcin and PIVKA-II were the most sensitive indices of changes in vitamin K1 status. Although the 5 mg vitamin K1/week dose improved these vitamin K parameters, normal levels were not achieved. Dietary supplementation with vitamin K(1), with vitamin D(3) and calcium or their combination, was examined in healthy older women during a 2-year, double-blind, placebo-controlled trial. Combined vitamin K with vitamin D plus calcium was associated with a modest but significant increase in BMC at the ultradistal radius but not at other sites in the hip or radius.
                The putative beneficial role of high dietary vitamin K(1) (phylloquinone) on BMD and the possibility of interactive benefits with vitamin D were studied in a 2-year double-blind, placebo-controlled trial in healthy Scottish women > or =60 years of age.
                Healthy, nonosteoporotic women (n = 244) were randomized to receive either (1) placebo, (2) 200 microg/day vitamin K(1), (3) 10 microg (400 IU) vitamin D(3) plus 1000 mg calcium/day, or (4) combined vitamins K(1) and D(3) plus calcium. Baseline and 6-month measurements included DXA bone mineral scans of the hip and wrist, markers of bone turnover, and vitamin status. Supplementation effects were tested using multivariate general linear modeling, with full adjustment for baseline and potential confounding variables.
                Significant bone mineral loss was seen only at the mid-distal radius but with no significant difference between groups. However, women who took combined vitamin K and vitamin D plus calcium showed a significant and sustained increase in both BMD and BMC at the site of the ultradistal radius. Serum status indicators responded significantly to respective supplementation with vitamins K and D. Over 2 years, serum vitamin K(1) increased by 157% (p < 0.001), the percentage of undercarboxylated osteocalcin (%GluOC) decreased by 51% (p < 0.001), serum 25-hydroxyvitamin D [25(OH)D] increased by 17% (p < 0.001), and PTH decreased by 11% (p = 0.049).
                These results provide evidence of a modest synergy in healthy older women from nutritionally relevant intakes of vitamin K(1) together with supplements of calcium plus moderate vitamin D(3) to enhance BMC at the ultradistal radius, a site consisting of principally trabecular bone. The substantial increase in gamma-carboxylation of osteocalcin by vitamin K may have long-term benefits and is potentially achievable by increased dietary intakes of vitamin K rather than by supplementation. To investigate the relationship between the common cold and vitamin C supplementation.
                A double-blind, 5-year randomized controlled trial.
                A village in Akita prefecture, one of the regions in Japan with the highest mortality from gastric cancer.
                Participants in annual screening programs for circulatory diseases conducted under the National Health and Welfare Services Law for the Aged, and diagnosed as having atrophic gastritis. Of the 439 eligible subjects, 144 and 161 were assigned to receive 50 or 500 mg of vitamin C, respectively, after protocol amendment. During the supplementation phase, 61 dropped out, and 244 completed the trial. Intervention: Daily vitamin C supplementation of 50 mg (low-dose group) or 500 mg (high-dose group).
                Total number of common colds (per 1000 person-months) was 21.3 and 17.1 for the low- and high-dose groups, respectively. After adjustment for several factors, the relative risks (95% confidence interval (CI)) of suffering from a common cold three or more times during the survey period was 0.34 (0.12-0.97) for the high-dose group. No apparent reduction was seen for the severity and duration of the common cold.
                A randomized, controlled 5-year trial suggests that vitamin C supplementation significantly reduces the frequency of the common cold but had no apparent effect on the duration or severity of the common cold. However, considering several limitations due to protocol amendment, the findings should be interpreted with caution. To determine the effectiveness of vitamin D and home-based quadriceps resistance exercise on reducing falls and improving the physical health of frail older people after hospital discharge.
                Multicenter, randomized, controlled trial with a factorial design.
                Five hospitals in Auckland, New Zealand, and Sydney, Australia.
                Two hundred forty-three frail older people.
                Patients were randomized to receive a single dose of vitamin D (calciferol, 300,000 IU) or placebo tablets and 10 weeks of high-intensity home-based quadriceps resistance exercise or frequency-matched visits.
                The primary endpoints were physical health according to the short-form health survey at 3 months and falls over 6 months. Physical performance and self-rated function were secondary endpoints. Assessments took place in the participants' homes at 3 and 6 months after randomization and were performed by blinded assessors.
                There was no effect of either intervention on physical health or falls, but patients in the exercise group were at increased risk of musculoskeletal injury (risk ratio = 3.6, 95% confidence interval = 1.5-8.0). Vitamin D supplementation did not improve physical performance, even in those who were vitamin D deficient (<12 ng/mL) at baseline.
                Neither vitamin D supplementation nor a home-based program of high-intensity quadriceps resistance exercise improved rehabilitation outcomes in frail older people after hospitalization. There was no effect of vitamin D on physical performance, and the exercises increased the risk of musculoskeletal injury. These findings do not support the routine use of these interventions at these dosages in the rehabilitation of frail older people. vitamin D supplementation reduces the incidence of fractures in older adults. This may be partly mediated by effects of vitamin D on neuromuscular function.
                to determine the effects of vitamin D supplementation on aspects of neuromuscular function known to be risk factors for falls and fractures.
                randomised, double-blind, placebo-controlled study.
                falls clinic taking referrals from general practitioners and accident and emergency department.
                139 ambulatory subjects (>/=65 years) with a history of falls and 25-hydroxyvitamin D (25OHD) </=12 microg/l. Intervention: patients were randomised to receive a single intramuscular injection of 600,000 i.u. ergocalciferol or placebo.
                assessments including biochemistry, postural sway, choice reaction time (CRT), aggregate functional performance time (AFPT), and quadriceps strength were carried out at baseline and 6 months post-intervention.
                baseline characteristics were comparable between both groups. 25OHD in the treatment group increased significantly at 6 months. AFPT deteriorated in the control group and improved in the intervention group, representing a significant difference between groups (+6.6 s versus -2.0 s, t = 2.80, P < 0.05). Similar changes were observed for CRT (-0.06 s versus +0.41 s, t = -2.52, P < 0.01) and postural sway (+0.0025 versus -0.0138, t = 2.35, P < 0.02). There was no significant difference in muscle strength change between groups (-10 N versus -2 N, t = -1.26, ns). A significant correlation between change in AFPT and change in 25OHD levels was observed (r = 0.19, P = 0.03). There was no significant difference in the number of falls (0.39 versus 0.24, t = 1.08, P = 0.28) or fallers (14 versus 11, P = 0.52) between two groups.
                vitamin D supplementation, in fallers with vitamin D insufficiency, has a significant beneficial effect on functional performance, reaction time and balance, but not muscle strength. This suggests that vitamin D supplementation improves neuromuscular or neuroprotective function, which may in part explain the mechanism whereby vitamin D reduces falls and fractures. Low bone mineral density (BMD) is prevalent in adults with cystic fibrosis and might be related to calcium and vitamin D malabsorption from the gastrointestinal tract. The aim of this study was to investigate the effect of calcium and vitamin D supplementation on BMD and bone metabolism in these subjects.
                Patients were invited to participate if they had a BMD Z score of -1 or less in the lumbar spine, proximal femur or distal forearm. Patients were randomised to receive calcium 1 g+vitamin D 800 IU or placebo daily, in addition to their regular vitamin D supplements (900 IU/day). BMD and bone biochemical markers were measured before and after 1 year of treatment.
                After 12 months, the treatment group (n=15) showed a reduced rate of bone loss compared with the control group (n=15) in the lumbar spine (mean difference 1.9% [CI -0.9% to 4.6%]), total hip (mean difference 0.7% [CI -2.2% to 3.5%]) and distal forearm (mean difference 1.7% [CI -2.2% to 5.5%]), but these changes did not reach statistical significance. There was also a trend towards a reduction in bone turnover in the treatment group.
                Calcium and vitamin D supplementation reduced the rate of bone turnover and bone loss in adult patients with cystic fibrosis, but these changes did not reach statistical significance. These data suggest that a longer term trial of this simple intervention would be justified. The bone mineral content (B.M.C.) in both forearms (related to total body calcium) was measured by photon absorptiometry for a controlled therapeutic trial in a representative sample of epileptic outpatients, comprising 226 patients treated with one or two major anticonvulsant drugs (phenytoin, phenobarbitone, primidone).Initially the mean B.M.C. value for all epileptic patients was 87% of normal. During treatment with 2,000 international units of vitamin D(2) daily for three months an average B.M.C. increase of 4% was found, whereas the B.M.C. values remained unchanged in the placebo group and in the control groups. The incidence of hypocalcaemia and raised serum alkaline phosphatase was 12% and 43% respectively. The biochemical indices of osteomalacia were related to B.M.C. These results indicate that epileptic patients should be closely supervised for the occurrence of anticonvulsant osteomalacia, and, possibly, receive prophylactic treatment with vitamin D. A randomised double-blind trial involving vitamin C/placebo supplementation was conducted on 57 elderly patients admitted to hospital with acute respiratory infections (bronchitis and bronchopneumonia). Patients were assessed clinically and biochemically on admission and again at 2 and 4 weeks after admission having received either 200 mg vitamin C per day, or placebo. This relatively modest oral dose led to a significant increase in plasma and white cell vitamin C concentration even in the presence of acute respiratory infection. Using a clinical scoring system based on major symptoms of the respiratory condition, patients supplemented with the vitamin fared significantly better than those on placebo. This was particularly the case for those commencing the trial most severely ill, many of whom had very low plasma and white cell vitamin C concentrations on admission. Various mechanisms by which vitamin C could assist this type of patient are discussed.
Evidence from randomised controlled trials on the benefits of routine vitamin K supplementation for people with CF is currently weak and limited to two small trials of short duration. However, no harm was found and until further evidence is available, the present recommendations should be adhered to.