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PubMed1995

[Vitamin disturbances in chronic renal insufficiency. I. Water soluble vitamins].

Deficiency and/or altered metabolism of vitamins in CRI is caused by uremic toxins, dietary restrictions, catabolic illness, losses during dialysis and drug interaction. There are no reports of consistent studies on vitamin status of water soluble vitamins in CRI. Vitamin B1 (thiamine) deficiency several authors found most frequently in CAPD patients. The cause of this deficiency depends probably on increased requirement of vitamin B1 due to high glucose intake with peritoneal dialysis solution. In patients with polyneuropathy high doses of thiamine pyrophosphate (Cocarboxylase), given i.v., can be helpful in this respect. There are conflicting reports concerning plasma level of vitamin B2 (riboflavin) in CRI patients. Some authors recommend its supplementation. The majority of patients with CRI exhibit biochemical and clinical signs of vitamin B6 deficiency. There exists an univocal opinion that supplementation of this vitamin effects the cellular immune system and the amino acid metabolism as well. An adequate dose of vitamin B6 is still a matter of dispute. Evidence of vitamin B12 deficiency has been reported rarely, thus, only few authors recommend the supplementation of it, mainly in CAPD patients. According to most authors the losses of folic acid and ascorbic acid during dialysis require oral supplementation. Despite the divergences in opinions concerning the deficiency of water-soluble vitamins in CRI patients, the supplementation of these vitamins is practised in many nephrological centers. The amount and the route of vitamins, administered to CRI patients, should be individualized.

Food, Fortified↗
PubMed1976

Differential effects of high dietary levels of vitamin A on the vitamin E-selenium nutrition of young and adult chickens.

Experiments were conducted to determine the nature of the interaction of high levels of vitamin A and vitamin E-selenium nutrition in the chicken. Results showed that chicks were protected from the vitamin E-selenium deficiency disease exudative diathesis (ED) by a high dietary level of vitamin A (1.0 X 10(6) IU/kg) which moderately depressed growth. A greater concentration (1.5 X 10(6) IU/kg) of vitamin A in the diets of hens fed a low vitamin E diet hastened their depletion of plasma tocopherols and increased plasma glutathione peroxidase (GSH-px) activity. At hatching the progeny of vitamin A-fed hens were severely depleted of plasma tocopherols but had normal plasma GSH-px activities. They showed increased susceptibility to ED when fed selenium-deficient, vitamin E-free diets for 2 weeks. Absorption studies using ligated duodenal loops or oral doses indicated that high-level dietary vitamin A promoted the enteric absorption of selenium but interfered with the absorption of vitamin E. The dual nature of these effects was related to the ED-protective influence of vitamin A when fed to chicks, and the ED-stimulative influence on progeny when vitamin A was fed to dams.

Age Factors↗
PubMed1999

Osteopathy and resistance to vitamin D toxicity in mice null for vitamin D binding protein.

A line of mice deficient in vitamin D binding protein (DBP) was generated by targeted mutagenesis to establish a model for analysis of DBP's biological functions in vitamin D metabolism and action. On vitamin D-replete diets, DBP-/- mice had low levels of total serum vitamin D metabolites but were otherwise normal. When maintained on vitamin D-deficient diets for a brief period, the DBP-/-, but not DBP+/+, mice developed secondary hyperparathyroidism and the accompanying bone changes associated with vitamin D deficiency. DBP markedly prolonged the serum half-life of 25(OH)D and less dramatically prolonged the half-life of vitamin D by slowing its hepatic uptake and increasing the efficiency of its conversion to 25(OH)D in the liver. After an overload of vitamin D, DBP-/- mice were unexpectedly less susceptible to hypercalcemia and its toxic effects. Peak steady-state mRNA levels of the vitamin D-dependent calbindin-D9K gene were induced by 1,25(OH)2D more rapidly in the DBP-/- mice. Thus, the role of DBP is to maintain stable serum stores of vitamin D metabolites and modulate the rates of its bioavailability, activation, and end-organ responsiveness. These properties may have evolved to stabilize and maintain serum levels of vitamin D in environments with variable vitamin D availability.

Animals↗
PubMed2003

Growth response to increasing doses of microencapsulated vitamin B12 and related changes in tissue vitamin B12 concentrations in cobalt-deficient lambs.

AIM: To investigate growth response of cobalt deficient lambs to increasing doses of microencapsulated vitamin B12, and to measure associated changes in serum and liver vitamin B12 concentrations over 243 days. METHODS: From a flock grazing pastures that had low cobalt (Co) levels (about 0.06 mg Co/kg dry matter), 4-6-week-old lambs (n=137) were assigned to four groups and received either no treatment or a subcutaneous injection of 3.0, 4.5 or 6.0 mg of microencapsulated vitamin B12 on Day 1. At approximately monthly intervals, all lambs were weighed and blood samples were collected from a selection (n=10) of monitor animals, up to Day 243. Liver biopsies were also carried out on the monitor lambs (n=8) on Days 1, 124 and 215. RESULTS: The vitamin B12-treated lambs grew significantly faster (p<0.001) than untreated animals. Liveweights after 243 days were 28, 45, 45 and 47 kg for the untreated, 3.0, 4.5 and 6.0 mg vitamin B12-treated lambs, respectively. Of the initial group of untreated lambs, 68% had to be removed before the end of the trial because of substantial weight loss, but none of the treated animals were similarly afflicted. Serum vitamin B12 concentrations increased in all vitamin B12-treated lambs, reaching a peak at Day 25, and those of the 4.5 and 6.0 mg vitamin B12-treated lambs remained significantly higher (except at Day 124) than the untreated lambs to Day 187. However, at Day 124, but not Day 215, the liver vitamin B12 concentrations of treated lambs were two to three times higher than those of controls. CONCLUSIONS: The growth rates of Co deficient lambs were markedly improved by injection of 3.0, 4.5 or 6.0 mg of microencapsulated vitamin B12, and liveweights were maintained for at least 243 days. Serum vitamin B12 concentrations were related to this growth response; concentrations of <220 pmol vitamin B12/l were associated with a 95% probability that lambs were Co deficient and would thus respond to Co/vitamin B12 supplementation. Based on these data, the current New Zealand reference criteria for Co deficiency should be reviewed. CLINICAL SIGNIFICANCE: An injection of 3 mg microencapsulated vitamin B12 given to lambs at tailing will treat Co deficiency and will increase and maintain liveweights in a flock for up to 8 months.

Journal Article↗
PubMed2003

Effect of five-year supplementation of vitamin C on serum vitamin C concentration and consumption of vegetables and fruits in middle-aged Japanese: a randomized controlled trial.

OBJECTIVE: This study was aimed at evaluating the effect of long-term vitamin C supplementation on serum and dietary vitamin C and identifying the factors associated with change in serum concentration. METHODS: A total of 439 subjects with atrophic gastritis initially participated in a randomized clinical trial using vitamin C and beta-carotene to prevent gastric cancer. We originally randomized the participants into four treatment groups using a 2x2 factorial design, whereby 0 or 15 mg/day beta-carotene and 50 or 500 mg/day vitamin C were administered in a double-blind manner. The beta-carotene component was terminated early after a mean treatment duration of four months. Before and upon early termination of beta-carotene supplementation, 134 subjects dropped out this trial, while 120 and 124 subjects took the vitamin C supplement at either 50 mg or 500 mg daily for five years. RESULTS: Changes in serum vitamin C were significantly higher in the high-dose group (38.5% increase, 95% CI = 27.0-49.9) than in the low-dose group (13.0% increase, 5.1-20.9) or in the dropout group (3.3% increase, -2.1-8.6) after five-year supplementation. The serum vitamin C at baseline was negatively associated with changes in serum vitamin C (p < 0.0001), while high-dose (p < 0.0001) and low-dose (p < 0.05) supplementation and female gender (p < 0.001) were positively associated. Dietary intake of vitamin C in the supplementation group was almost identical before and after five-year supplementation of vitamin C (2.31 mg/day decrease, 95% CI = -15.3-10.7), while a 17.7 mg/day decrease (95% CI = -44.2-8.86) was observed in the drop-out group. CONCLUSION: Five-year vitamin C supplementation induces a remarkable increase in serum vitamin C concentration, and our intervention program appears to have no effect on dietary vitamin C intake.

Adult↗
PubMed1996

Effect of feeding various dietary vitamin B6 concentrations during gestation and lactation on vitamin B6 level in liver and carcass of rat dams.

The present investigation was designed to determine the vitamin B6 concentration in liver and carcass of rat dams fed various dietary vitamin B6 levels during gestation and lactation. Therefore, gravid female rats received 0.6, 3, 6, 18 or 180 mg vitamin B6 per kg diet. After parturition each group was divided into 2 groups of 8 dams each, which received then a diet with 3, respectively 6 mg/kg vitamin B6 during lactation. At the end of the experiment at day 14 of lactation weight gain and food consumption as well as liver and carcass weights did not differ within the groups. The present data clearly show that both in liver and carcass of lactating rats, there exists only a slight dose-response-relationship between the dietary vitamin B6 intake and the vitamin B6 concentration in body tissue. Moreover, liver reflects the various vitamin B6 supplies during gestation and lactation somewhat better than carcass. The distribution of the vitamins did not differ among the groups and was therefore independent of the vitamin B6 supply. The present findings, especially regarding the liver, elucidate, that an adequate vitamin B6 supply during lactation can not compensate for a lack of vitamin B6 during gestation and vice versa a high dose of vitamin B6 during gestation did not completely protect against a suboptimal vitamin B6 during lactation.

Animals↗
PubMed1998

Evidence that vitamin D3 increases serum 25-hydroxyvitamin D more efficiently than does vitamin D2.

In all species tested, except humans, biological differences between vitamins D2 and D3 are accepted as fact. To test the presumption of equivalence in humans, we compared the ability of equal molar quantities of vitamin D2 or D3 to increase serum 25-hydroxyvitamin D [25(OH)D], the measure of vitamin D nutrition. Subjects took 260 nmol (approximately 4000 IU) vitamin D2 (n=17) or vitamin D3 (n=55) daily for 14 d. 25(OH)D was assayed with a method that detects both the vitamin D2 and D3 forms. With vitamin D3, mean (+/-SD) serum 25(OH)D increased from 41.3+/-17.7 nmol/L before to 64.6+/-17.2 nmol/L after treatment. With vitamin D2, the 25(OH)D concentration went from 43.7+/-17.7 nmol/L before to 57.4+/-13.0 nmol/L after. The increase in 25(OH)D with vitamin D3 was 23.3+/-15.7 nmol/L, or 1.7 times the increase obtained with vitamin D2 (13.7+/-11.4 nmol/L; P=0.03). There was an inverse relation between the increase in 25(OH)D and the initial 25(OH)D concentration. The lowest 2 tertiles for basal 25(OH)D showed larger increases in 25(OH)D: 30.6 and 25.5 nmol/L, respectively, for the first and second tertiles. In the highest tertile [25(OH)D >49 nmol/L] the mean increase in 25(OH)D was 13.3 nmol/L (P < 0.03 for comparison with each lower tertile). Although the 1.7-times greater efficacy for vitamin D3 shown here may seem small, it is more than what others have shown for 25(OH)D increases when comparing 2-fold differences in vitamin D3 dose. The assumption that vitamins D2 and D3 have equal nutritional value is probably wrong and should be reconsidered.

Adult↗
PubMed1985

[Effect of varying vitamin B6 intake levels on the vitamin B6 status of fetuses and reproductive organs].

In order to study the influence of varying vitamin B6 intake levels on the reproductive performance and the vitamin B6 status of fetuses and reproductive organs, 30 pregnant rats (Sprague Dawley strain) were fed a semisynthetic casein diet supplemented with 1, 6, 12, 24 and 48 mg vitamin B6/kg throughout pregnancy. On days 19 of pregnancy the rats were killed. Fetuses, placenta, amniotic fluid, amnion, uterus and mammary gland were analysed microbiologically for their vitamin B6 content. Reproductive performance was not influenced by the dietary treatment. Vitamin B6 concentrations in fetuses, placenta and amniotic fluid of mothers treated with the low 1-ppm vitamin B6 diet were significantly decreased. At a vitamin B6 supply of 6 ppm, however, tissue saturation was already reached in these organs. Accordingly, the whole vitamin B6 retention in the reproductive product plateaued at an intake level of 6 ppm vitamin B6 at 37 micrograms vitamin B6 per animal. These results indicate therefore that a level of 6 ppm dietary vitamin B6 is sufficient to guarantee an optimum vitamin B6 status in the reproductive product, and higher vitamin B6 supplementations showed no further effect on the parameters investigated.

Amniotic Fluid↗
PubMed1989

Differences in mineral metabolism among nonhuman primates receiving diets with only vitamin D3 or only vitamin D2.

We tested for differences in aspects of mineral metabolism during the administration of diets with only vitamin D3 or only vitamin D2 in four nonhuman anthropoid primate species [two catarrhini, Macaca fascicularis (crab-eating macaque) and Macaca mulatta (rhesus macaque), and two platyrrhini, Saimiri sciureus (squirrel monkey) and Aotus vociferans (night monkey)]. All four species maintained approximately 2- to 3-fold higher serum 25-hydroxyvitamin D (25OHD) level while receiving vitamin D3 than while receiving similar amounts of vitamin D2. Serum 25OHD in M. mulatta receiving the standard primate dietary supplement of vitamin D3 was high enough (360 +/- 60 vs. 70 +/- 25 nM in vitamin D-supplemented humans; P less than 0.0001) to suggest that this widely used level of vitamin D3 supplementation is excessive for some M. mulatta. Serum 24,25-dihydroxyvitamin D [24,25-(OH)2D] in A. vociferans was uniquely high [P less than 0.01; species mean, 19 +/- 5, 95 +/- 12, and 27 +/- 5 nM in groups receiving diets with 1.5 IU vitamin D3/g, 6.6 IU vitamin D3/g, and 15 IU vitamin D2/g, respectively; mean 24,25-(OH)2D from the other three species pooled across three diets was 7 +/- 5 nM]. We confirmed relative resistance to 1,25-(OH)2D in S. sciureus, manifested by osteomalacia and moderately high serum 1,25-(OH)2D. Serum 1,25-(OH)2D in S. sciureus increased 4-fold (P less than 0.05) when the precursor in serum was changed from 250HD3 to 250HD2, suggesting that this species shows more severe resistance to 1,25-(OH)2D2 than to 1,25-(OH)2D3. In conclusion, we found many differences in vitamin D metabolism among four nonhuman anthropoid primate species. The striking feature in A. vociferans (high, 24,25-(OH)2D without high 25OHD in serum independent of whether diet contained only vitamin D3 or only vitamin D2) should allow determination of whether 24,25-(OH)2D functions as a unique agonist or an inactive metabolite in this species.

Animals↗
PubMed1986

Vitamin D3 and D3 metabolites in young goats fed varying amounts of calcium and vitamin D3.

Twenty-four male goats, 2 to 4 wk of age, were allotted to four dietary treatments in a 2 X 2 factorial design and, for 20 wk, were fed a milk diet at 12.5% body weight. Treatments varied in amounts of supplemental calcium and vitamin D3. Daily allowances per kilogram body weight were: 9.4 IU vitamin D3 (basal), 9.4 IU vitamin D3 plus 406 mg calcium carbonate (basal plus Ca), 940 IU vitamin D3 (basal plus D3), and 940 IU vitamin D3 plus 406 mg calcium carbonate (basal plus Ca plus D3). At the end of wk 7, a corn supplement was added to all diets at 1% body weight daily. Addition of vitamin D3 to the diet resulted in a dramatic increase in plasma concentrations of vitamin D3. Goats in the basal plus D3 and basal plus Ca plus D3 groups had nearly 100 X greater concentrations of vitamin D3 than goats in the basal and basal plus Ca groups. When greater amounts of vitamin D3 were fed, dietary calcium interacted to decrease plasma vitamin D3 concentrations. Plasma concentrations of 25-hydroxyvitamin D3 were unaffected by additional dietary calcium but were increased by dietary vitamin D3, increasing sixfold to seven-fold in the basal plus D3 and basal plus Ca plus D3 groups. Supplemental calcium resulted in decreased plasma 1,25-dihydroxyvitamin D3. No signs of vitamin D toxicity were noted. The physiological responses reported implicate the goat as a potential animal model for vitamin D research in dairy cattle.

Animals↗
PubMed1981

Calcinogenic activity of vitamin D3 and vitamin D3 palmitate in rat and rabbit.

Experimental hypervitaminosis D was produced in rabbits by feeding 25,000 I.U. vitamin D3 or the corresponding amount of vitamin D3 palmitate per kg of diet. Hypercalcemia and hyperphosphatemia was accompanied by increased CaBP activity and reduced weight gain in the vitamin D3 group as well as in the vitamin D3 ester group. The degree of calcification in the aorta and in the kidney also was similar in both groups. Increasing the vitamin intake by giving 10,000 I.U. vitamin D3 or vitamin D3 palmitate per day resulted in earlier and more widespread calcific deposits. In rats, receiving 50,000 I.U. vitamins D3 or vitamin D3 palmitate per kg of diet, calcification in soft tissue was much less extensive than in rabbits. But again, no difference was seen between vitamin D3 and vitamin D3 palmitate. These results indicate, that vitamin D3 esters are not suitable as a less calcinogenic form of vitamin D3.

Animals↗
PubMed1993

A randomized trial of vitamin A and vitamin E supplementation for retinitis pigmentosa.

OBJECTIVE: To determine whether supplements of vitamin A or vitamin E alone or in combination affect the course of retinitis pigmentosa. DESIGN: Randomized, controlled, double-masked trial with 2 x 2 factorial design and duration of 4 to 6 years. Electroretinograms, visual field area, and visual acuity were measured annually. SETTING: Clinical research facility. PATIENTS: 601 patients aged 18 through 49 years with retinitis pigmentosa meeting preset eligibility criteria. Ninety-five percent of the patients completed the study. There were no adverse reactions. INTERVENTION: Patients were assigned to one of four treatment groups receiving 15,000 IU/d of vitamin A, 15,000 IU/d of vitamin A plus 400 IU/d of vitamin E, trace amounts of both vitamins, or 400 IU/d of vitamin E. MAIN OUTCOME MEASURE: Cone electroretinogram amplitude. RESULTS: The two groups receiving 15,000 IU/d of vitamin A had on average a slower rate of decline of retinal function than the two groups not receiving this dosage (P = .01). Among 354 patients with higher initial amplitudes, the two groups receiving 15,000 IU/d of vitamin A were 32% less likely to have a decline in amplitude of 50% or more from baseline in a given year than those not receiving this dosage (P = .01), while the two groups receiving 400 IU/d of vitamin E were 42% more likely to have a decline in amplitude of 50% or more from baseline than those not receiving this dosage (P = .03). While not statistically significant, similar trends were observed for rates of decline of visual field area. Visual acuity declined about 1 letter per year in all groups. CONCLUSIONS: These results support a beneficial effect of 15,000 IU/d of vitamin A and suggest an adverse effect of 400 IU/d of vitamin E on the course of retinitis pigmentosa.

Adolescent↗
PubMed2000

Vitamin K prior to preterm birth for preventing neonatal periventricular haemorrhage.

BACKGROUND: Preterm infants are at risk of periventricular haemorrhage. This can damage the brain and lead to neurodevelopmental abnormalities, including cerebral palsy. It has been suggested that vitamin K might improve coagulation in preterm infants. OBJECTIVES: The objective of this review was to assess the effects of vitamin K administered to women at risk of imminent very preterm birth to prevent periventricular haemorrhage and associated neurological injury in the infant. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group trials register, Cochrane Controlled Trials Register, and bibliographies up to January 1999. SELECTION CRITERIA: Randomised or quasi-randomised trials of vitamin K administered parenterally or orally to women at risk of imminent preterm birth. The primary outcomes were neonatal mortality, neonatal neurological morbidity, as measured by the presence of periventricular haemorrhage (PVH) on ultrasound during the first week of life, and long term neurodevelopment. Secondary outcomes included other neonatal morbidity and any maternal side effects. DATA COLLECTION AND ANALYSIS: Eligibility, trial quality assessment and data extraction were done independently by two reviewers. MAIN RESULTS: Five trials were included, involving more than 420 women. The trials were of variable quality. Antenatal vitamin K was associated with a non-significant trend to a reduction in all grades of periventricular haemorrhage (relative risk (RR) 0.82, 95% confidence interval (CI) 0.67-1.00) and in severe PVH (grades 3 and 4) (RR 0.75, 95% CI 0.45-1.25) for babies receiving prenatal vitamin K compared with control babies. This trend disappeared when poorer quality trials were excluded. Information on neurodevelopment was given for a small sample of children in one trial and no differences were seen. REVIEWER'S CONCLUSIONS: Vitamin K administered to women prior to very preterm birth does not appear to be able to significantly prevent periventricular haemorrhages in preterm infants.

Cerebral Hemorrhage↗
PubMed1997

Prevention of vitamin K deficiency bleeding: efficacy of different multiple oral dose schedules of vitamin K.

UNLABELLED: There is consensus that late vitamin K deficiency bleeding (VKDB) should be prevented by vitamin K prophylaxis. One single dose of 1 mg vitamin K1 is effective if given i.m. or s.c., but not if given orally. Repeated oral doses might be as effective as the parenteral dose but the optimal dose regimen remains to be established. Different oral dose schedules are presently used in different countries. In Australia, Germany, The Netherlands and Switzerland active surveillance data on late VKDB were collected in a similar manner and failure rates compared. Identical case definitions were used. There were three basic strategies for oral and one for parenteral vitamin K prophylaxis for healthy newborns in the four countries: (1) daily supplementation of low dose vitamin K (25 micrograms) for breast-fed infants (The Netherlands); (2) 3 x 1 mg orally [Australia (January 1993-March 1994) and Germany (December 1992-December 1994)]; (3) 1 mg vitamin K i.m. (Australia since March 1994); and (4) 2 x 2 mg vitamin K (new mixed micellar preparation) (Switzerland). The respective failure rates per 100,000 live births (including cases given all recommended doses and those given incomplete prophylaxis) were for strategy: (1) 0.2 (0-1.3) in The Netherlands; (2) 2.3 (95% CI 1.6-3.4) in Germany and 2.5 (1.1-4.8) in Australia (oral prophylaxis); (3) Australia (i.m. prophylaxis) 0 (0-0.9); and (4) 3.6 (0.7-10.6) in Switzerland. The failure rates for complete prophylaxis only were: strategy (1) 0 (0-0.7) in The Netherlands; (2) 1.8 (1.1-2.8) in Germany and 1.5 (0.5-3.6) in Australia; (3) Australia (i.m.) 0 (0-0.9); and (4) 1.2 (0-6.5) in Switzerland. CONCLUSIONS: The Australian data confirm that three oral doses of 1 mg vitamin K are less effective than i.m. vitamin K prophylaxis. A daily low oral dose of 25 micrograms vitamin K1 following an initial oral dose of 1 mg after birth for exclusively breast-fed infants may be as effective as parenteral vitamin K prophylaxis. The effectiveness of the "mixed-micellar" preparation of vitamin K1 needs further study.

Administration, Oral↗
PubMed1987

Synthesis of 25-hydroxy-[26,27-3H]vitamin D2, 1,25-dihydroxy-[26,27-3H]vitamin D2 and their (24R)-epimers.

Synthesis of a C-24-epimeric mixture of 25-hydroxy-[26,27-3H]vitamin D2 and a C-24-epimeric mixture of 1,25-dihydroxy-[26,27-3H]vitamin D2 by the Grignard reaction of the corresponding 25-keto-27-nor-vitamin D2 and 1 alpha-acetoxy-25-keto-27-nor-vitamin D3 with tritiated methyl magnesium bromide is described. Separation of epimers by high-performance liquid chromatography afforded pure radiolabeled vitamins of high specific activity (80 Ci/mmol). The identities and radiochemical purities of 25-hydroxy-[26,27-3H[vitamin D2 and 1,25-dihydroxy-[26,27-3H]vitamin D2 D2 were established by cochromatography with synthetic 25-hydroxyvitamin D2 or 1,25-dihydroxyvitamin D2. Biological activity of 25-hydroxy-[26,27-3H]vitamin D2 was demonstrated by its binding to the rat plasma binding protein for vitamin D compounds, and by its in vitro conversion to 1,25-dihydroxy-[26,27-3H]vitamin D2 by kidney homogenate prepared from vitamin D-deficient chickens. The biological activity of 1,25-dihydroxy-[26,27-3H]vitamin D2 was demonstrated by its binding to the chick intestinal receptor for 1,25-dihydroxyvitamin D3.

25-Hydroxyvitamin D 2↗
PubMed2002

Influence of apolipoprotein E polymorphism on plasma vitamin A and vitamin E levels.

BACKGROUND: Plasma concentrations of vitamins A and E are positively correlated with those of concurrent lipids and, on the other hand, lipid levels are influenced by apolipoprotein E polymorphism. Therefore, the effect of this polymorphism on both vitamins was analysed in an adult population. MATERIALS AND METHODS: Subjects were recruited from a working population. Their anthropometric, lifestyle and dietary intake variables and menopausal status were recorded. Their apolipoprotein E phenotype and their plasma vitamins A and E (by high-performance liquid chromatography) and lipid (enzymatically) concentrations were determined after an overnight fast. The associations of the phenotype with vitamins and lipids were studied in men and women separately and controlling for significant covariates. RESULTS: The apolipoprotein E phenotype was associated with the concentrations of total, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol in women, whereas no associations with lipids were found in men. Vitamin A and vitamin E levels were higher in men than in women, but only the difference in the former persisted after lipid adjustment. Apolipoprotein E2 slightly increased vitamin A levels in women, an effect which was still evident with lipid adjustment. Actually, both the apolipoprotein E phenotype and triglyceride were selected as significant predictors of this vitamin by multiple regression. This phenotype did not affect vitamin E levels in either sex. CONCLUSIONS: Lipids do not mediate the effect of gender on vitamin A levels. Apolipoprotein E polymorphism is an independent determinant of vitamin A levels in women. Pending confirmation by others, we propose that enhancement of this vitamin may contribute to the beneficial impact of the epsilon2 allele on human ageing and health.

Adult↗
PubMed2001

Feeding dried purple laver (nori) to vitamin B12-deficient rats significantly improves vitamin B12 status.

To clarify the bioavailability of vitamin B12 in lyophylized purple laver (nori; Porphyra yezoensis), total vitamin B12 and vitamin B12 analogue contents in the laver were determined, and the effects of feeding the laver to vitamin B12-deficient rats were investigated. The amount of total vitamin B12 in the dried purple laver was estimated to be 54.5 and 58.6 (se 5.3 and 7.5 respectively) microg/100 g dry weight by Lactobacillus bioassay and chemiluminescent assay with hog intrinsic factor respectively. The purple laver contained five types of biologically active vitamin B12 compounds (cyano-, hydroxo-, sulfito-, adenosyl- and methylcobalamin), in which the vitamin B12 coezymes (adenosyl- and methylcobalamin) comprised about 60 % of the total vitamin B12. When 9-week-old vitamin B12-deficient rats, which excreted substantial amounts of methylmalonic acid (71.7(se 20.2) micromol/d) in urine, were fed the diet supplemented with dried purple laver (10 microg/kg diet) for 20 d, urinary methylmalonic acid excretion (as an index of vitamin B12 deficiency) became undetectable and hepatic vitamin B12 (especially adenosylcobalamin) levels were significantly increased. These results indicate that vitamin B12 in dried purple laver is bioavailable to rats.

Animals↗
PubMed2002

High vitamin A content in some small indigenous fish species in Bangladesh: perspectives for food-based strategies to reduce vitamin A deficiency.

Recognising the importance of fish in the Bangladeshi diet, the objective of the present study was to screen commonly consumed fish species for vitamin A content to evaluate the potential of fish as a vitamin A source in food-based strategies to combat vitamin A deficiency. Samples of 26 commonly consumed fish species and one crustacean were collected in Kishoreganj and Mymensingh, Bangladesh. To obtain edible parts, the fish were cleaned by Bangladeshi women according to traditional practices. Distribution of vitamin A in parts of the fish and the effect of the cleaning practices on the vitamin A content in#10; edible parts were assessed. The content of vitamin A compounds was analysed by high-performance liquid chromatography. The vitamin A content in small fish ranged from 2680 retinol equivalents (RE)/100 g raw edible parts in mola (Amblypharyngodon mola) to 20 RE/100 g raw edible parts in chata (Colisa lalia; an alternative scientific name is Colisa lalius). The vitamin A content in cultured species, silver carp (Hypophthalmichthys molitrix), rui (Labeo rohita), mrigal (Cirrhinus mrigala) and tilapia (Oreochromis niloticus) was low, <30 RE/100 g raw edible parts. In mola, 90% of the vitamin A was found in the eyes and viscera. The vitamin A content in the screened fish species was highly variable, by more than a factor of 100. The existence of commonly consumed fish in Bangladesh belonging to the categories of very high and high vitamin A content offers a great unexploited potential for food-based strategies to improve the vitamin A intake by promoting the production and consumption of these species.

Animals↗