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| Esther E. J. Valk and Gerard Hornstra Relationship Between Vitamin E Requirement and Polyunsaturated Fatty Acid Intake in Man: a Review |
Zusammenfassung Summary |
| T. Furusho, E. Kataoka, T. Yasuhara, M. Wada
and S. Masushige Retinol Equivalence of Carotenoids Can be Evaluated by Hepatic Vitamin A Content |
Zusammenfassung Summary |
| Mathilde Kersting, Ute Alexy, Wolfgang Sichert-Hellert Vitamin Intake of 1- to 18-Year-Old German Children and Adolescents in the Light of Various Recommendations |
Zusammenfassung Summary |
| Jeanne Chantal Essama-Tjani, Jean-Claude Guilland,
Françoise Fuchs, Marie Lombard and Dominique Richard Changes in Thiamin, Riboflavin, Niacin, b-carotene, Vitamins C, A, D and E Status of French Elderly Subjects during the First Year of Institutionalization |
Zusammenfassung Summary |
| Nahid Salarkia1, Fereidoun Azizi2, Masood
Kimiagar1, Hamid Zakeri, Sedigheh Soheilikhah and Mahtalat Nafarabadi Monitoring Iodine Following Consumption of Iodized Salt in Tehrani Inhabitants |
Zusammenfassung Summary |
| Y. Min1, K. Ghebremeskel1, M.A. Crawford1,
Joo-Hyun Nam2, Ahm Kim2, Ja-Nam Koo2 and Hiramitsu Suzuki Pregnancy Reduces Arachidonicand Docosahexaenoic in Plasma Triacylglycerols of Korean Women |
Zusammenfassung Summary |
Zusammenfassungen / Summaries
Summary
Vitamin E is the general term for all tocopherols and tocotrienols,
of which a-tocopherol is the natural and biologically most active
form. Although g-tocopherol makes a significant contribution to
the vitamin E CONTENT in foods, it is less effective in animal
and human tissues, where a-tocopherol is the most effective chain-breaking
lipid-soluble antioxidant. The antioxidant function of vitamin
E is critical for the prevention of oxidation of tissue PUFA.
Animal experiments have shown that increasing the degree of dietary
fatty acid unsaturation increases the peroxidizability of the
lipids and reduces the time required to develop symptoms of vitamin
E deficiency. From these experiments, relative amounts of vitamin
E required to protect the various fatty acids from being peroxidized,
could be estimated.
Since systematic studies on the vitamin E requirement in relation
to PUFA consumption have not been performed in man, recommendations
for vitamin E intake are based on animal experiments and human
food intake data. An intake of 0.6 mg a-tocopherol equivalents
per gram linoleic acid is generally seen as adequate for human
adults. The minimum vitamin E requirement at consumption of fatty
acids with a higher degree of unsaturation can be calculated by
a formula, which takes into account the peroxidizability of unsaturated
fatty acids and is based on the results of animal experiments.
There are, however, no clear data on the vitamin E requirement
of humans consuming the more unsaturated fatty acids as for instance
EPA (20:5, n-3) and DHA (22:6, n-3). Studies investigating the
effects of EPA and DHA supplementation have shown an increase
in lipid peroxidation, although amounts of vitamin E were present
that are considered adequate in relation to the calculated oxidative
potential of these fatty acids. Furthermore, a calculation of
the vitamin E requirement, using recent nutritional intake data,
shows that a reduction in total fat intake with a concomitant
increase in PUFA consumption, including EPA and DHA, will result
in an increased amount of vitamin E required.
In addition, the methods used in previous studies investigating
vitamin E requirement and PUFA consumption (for instance erythrocyte
hemolysis), and the techniques used to assess lipid peroxidation
(e.g. MDA analysis), may be unsuitable to establish a quantitative
relation between vitamin E intake and consumption of highly unsaturated
fatty acids. Therefore, further studies are required to establish
the vitamin E requirement when the intake of longer-chain, more-unsaturated
fatty acids is increased. For this purpose it is necessary to
use functional techniques based on the measurement of lipid peroxidation
in vivo. Until these data are available, the widely used ratio
of at least 0.6 mg a-TE/g PUFA is suggested. Higher levels may
be necessary, however, for fats that are rich in fatty acids containing
more than two double bonds.
Key words
Vitamin E, tocopherol, diet, polyunsaturated fatty acids, review
International Journal for Vitamin and Nutrition Research,
Band 70, 2000, Heft 2 © Verlag Hans Huber AG, Bern
Summary
The present study demonstrates a new method to evaluate the bioavailability of carotenoids based on the calculation of the hepatic retinol contents. Weaning male rats of Wistar strain were divided into 5 groups. Each group respectively received retinol acetate (200010000 IU per kg diet), a-carotene (24006000 mg per kg diet), b-carotene (24006000 mg per kg diet), mixture of a- and b-carotenes in the ratio of 1:2 (2400 and 4800 mg per kg dit), and palm-carotene oil (24006000 mg per kg diet). The derived retinol equivalences of each carotenoid calculated according to the hepatic retinol contents were almost constant regardless of the volume of respective intake (a-carotene: 1.25 mg per IU; b-carotene: 0.59 mg per IU; mixture of a- and b-carotene in the ratio of 1:2: 0.96 mg per IU; Palm-carotene oil: 1.23 mg per IU). The results suggest that the hepatic retinol contents can be used as a new measure to evaluate the vitamin A bioavailability of carotenoids.
Key words
Vitamin A, provitamin A, carotenoid, a-carotene, b-carotene, retinol equivalence
International Journal for Vitamin and Nutrition Research,
Band 70, 2000, Heft 2 © Verlag Hans Huber AG, Bern
Summary
Data on the vitamin intake during childhood and adolescence are rare in Europe. Here, age and sex specific percentiles of the absolute intakes and relative densities (per MJ) of retinol, carotenoids, vitamins A, E, C, B1, B2, B6, niacin and folate in a sample of 627 subjects between the age of 1 and 18 years are reported and compared to the actual recommendations from Germany, the EC and the USA. The evaluation of the intakes clearly depends on the reference value chosen. In total, the vitamin intake can be assessed to range between satisfactory and generous with the exception of folate which ranged consistently below the references.
Key words
Nutrition survey, children, adolescents, vitamin intake, recommendations
International Journal for Vitamin and Nutrition Research,
Band 70, 2000, Heft 2 © Verlag Hans Huber AG, Bern
Summary
Vitamin status was assessed in 26 recently institutionalized
elderly subjects by combining dietary and biochemical measurements
of thiamin, riboflavin, niacin, b-carotene, vitamins C, A, D and
E at admission (P1), and 1.5 (P2), 3.0 (P3), 4.5 (P4), 6.0 (P5),
12 (P6) months later.
At admission, except for vitamin A, mean vitamin intakes were
lower than the 1992 French Recommended Dietary Allowance. Thiamin,
vitamins C, A and E status seemed nearly satisfactory as less
than one-fourth of the population sample had blood values lower
than the cut-off point for thiamin (erythrocyte thiamin pyrophosphate
< 0.17 mmol/l), vitamin A (serum retinol < 1.05 mmol/l),
vitamin C (serum vitamin C < 11.3 mmol/l) and vitamin E (serum
a-tocopherol < 9.3 mmol/l) or higher than the cut-off point
for thiamin (erythrocyte transketolase activity coefficient >
1.19). Almost half of the subjects for riboflavin, and almost
all non supplemented subjects for vitamin D were in risk of vitamin
deficiency (46% had an erythrocyte glutathione reductase
activity coefficient > 1.19 and 72% had a plasma 25(OH)D3 <
25 nmol/l). During the study, vitamins status remained unchanged
for riboflavin, niacin, vitamins A, D and E, improved for vitamin
C (P = 0.004) or impaired for thiamin (P = 0.008).
Thus, institutionalization seemed to have no effect on riboflavin,
niacin, vitamins A, D and E status and a slight effect on thiamin
and vitamin C status.
Key words
Vitamins, intake, vitamin status, elderly, geriatric patients, France
International Journal for Vitamin and Nutrition Research,
Band 70, 2000, Heft 2, © Verlag Hans Huber AG, Bern
Summary
As the production, distribution and consumption of iodized
salt has increased in recent years, this study was carried out
to assess iodine status in Tehran in 1996.
1146 families comprising 5140 subjects in the twenty districts
of Tehran city from all age groups were randomly selected. Thyroid
size was examined by palpation and graded according to the WHO
classification. In 163 families selected randomly, thyroid size
was determined by ultrasonography and urinary iodine was measured
by digestion method. Serum T4, T3 and TSH (IRMA) concentrations
were also assayed by kits. Percentage of grades 1 & 2 goiter
were 44 & 44% in females and 49 & 33% in males respectively.
Median urinary iodine was 17.5 mg/dl. Mean serum T4, T3 and TSH
were 8.41 ± 1.4 mg/dl, 170 ± 37 ng/dl and 1.4 ±
0.8 m/ml, respectively. In 118 children aged 610 years median
urinary iodine was 17.5 mg/dl. Thyroid volume in children was
4.3 ± 1.9 ml. No correlation was established between the
thyroid volume and goiter grade. This study points to the adequacy
of iodine intake in the majority of families residing in Tehran.
Key words
Iodine deficiency, urinary iodine, thyroid hormones, iodized salt
International Journal for Vitamin and Nutrition Research,
Band 70, 2000, Heft 2 © Verlag Hans Huber AG, Bern
Summary
Plasma triacylglycerol (TG) fatty acid composition of healthy non-pregnant and non-lactating women, expectant mothers and their term neonates from Seoul, South Korea was investigated. They were ethnically homogenous and the women had comparable age and parity. Blood samples were obtained at recruitment, third trimester and birth from the non-pregnant women, expectant mothers and neonates respectively. Percent levels of linoleic and arachidonic acids and n-6 metabolites and total n-6 were significantly lower in the pregnant women than in the non-pregnants (p < 0.0001). Similarly, there were lower levels of alpha-linolenic (p = 0.033), eicosapentaenoic and docosahexaenoic acids and n-3 metabolites and total n-3 (p < 0.0001) in the expectant mothers. Compared with their mothers, the neonates had higher proportions of dihomo-gamma-linolenic, arachidonic, docosatetraenoic and docosapentaenoic acids and n-6 metabolites (p < 0.0001) and lower linoleic acid (p < 0.0001). Of the n-3 series, alpha-linolenic acid was lower (p < 0.0001) and eicosapentaenoic, docosapentaenoic and docosahexaenoic acids and n-3 metabolites and total n-3 higher (p < 0.0001) in the neonates compared with their mothers. The study reveals that pregnancy is associated with a reduction in the relative levels of plasma triacylglycerol arachidonic and docosahexaenoic acids. Moreover, it indicates that the decline is a manifestation of selective transfer of these fatty acids to the developing fetus.
Key words
Pregnant women, non-pregnant women, newborn babies, plasma triacylglycerol, arachidonic, docosahexaenoic
International Journal for Vitamin and Nutrition Research,
Band 70, 2000, Heft 2 © Verlag Hans Huber AG, Bern