Blood vitamin and mineral levels in 7-17 years old Turkish children.

Blood vitamin (thiamin, riboflavin, vitamins B6, B12, C, A, and E, folate and beta-carotene), mineral (iron and zinc), alkaline phosphatase and cholesterol levels and hematocrit were assessed in 960 school-age children selected by random sampling from urban and rural regions of Turkey. Nutritional statuses of the children according to each index were compared with respect to age, sex, area and type of settlement. A biochemical deficiency was observed in 20.1% of the children for thiamin, in 89.9% for riboflavin, in 83.4% for vitamin B6, in 23.3% for folate, in 5.9% for vitamin B12, in 43.0% for vitamin C, in 11.6% for vitamin A, in 3.5% for beta-carotene, in 21.8% for vitamin E, in 6.1% for iron, and in 15.7% for zinc. Hematocrit was low in 54.3%. Alkaline phosphatase and cholesterol levels were found to be above normal in 54.6% and 4.9% of the children respectively. It is surmised that a major cause of the deficiencies was an ignorance of good dietary practice. Although the children were found to be relatively short according to the National Center for Health Statistics standards, their normalised weights were within acceptable limits, which suggested a prevalence of stunting but not wasting in this population.

Plasma antioxidant vitamins and subsequent cancer mortality in the 12-year follow-up of the prospective Basel Study.

Plasma antioxidant vitamins A, C, and E and carotene were measured in a group of 2,974 men participating in the third examination of the prospective Basel Study in 1971-1973. In 1985, the vital status and mortality of all participants were assessed. A total of 204 men had died from cancer, including 68 with bronchus cancer and 37 with gastrointestinal cancer (20 with stomach cancer and 17 with large bowel cancer excluding cancer of the rectum). Overall mortality from cancer was associated with low mean plasma levels of carotene adjusted for cholesterol (p less than 0.01) and of vitamin C (p less than 0.01). Bronchus and stomach cancers were associated with a low mean plasma carotene level (p less than 0.01). Subjects with subsequent stomach cancer also had lower mean vitamin C and lipid-adjusted vitamin A levels than did survivors (p less than 0.05). After calculation of the relative risk using the Cox model with exclusion of mortality during the first 2 years of follow-up, low plasma carotene (below quartile 1) was associated with a significantly increased risk for bronchus cancer (relative risk (RR) = 1.8, p less than 0.05), low plasma levels of carotene and vitamin A with all cancers (RR = 2.47, p less than 0.01), and low plasma retinol in older subjects (greater than age 60 years) with lung cancer (RR = 2.17, p less than 0.05). Low levels of vitamin C increased the risk of stomach cancer (RR = 2.38) and gastrointestinal cancer (RR = 2.46) in older subjects, but only significantly with the inclusion of the first 2 years. The authors conclude that low plasma levels of antioxidant vitamins are associated with an increased risk of subsequent cancer mortality. This effect was stronger in men above age 60 years at blood sampling, and the effect seems to be site-specific.

Nutritional status, grip strength, and immune function in institutionalized elderly.

The effects of vitamin supplementation on grip strength and immune function was studied in a group of institutionalized elderly with a relatively higher prevalence of low and below acceptable biochemical parameters of vitamin C, pyridoxine, folic acid, riboflavin, iron and zinc nutriture. The vitamin supplementation has resulted in a statistically significant increase in the level of biochemical parameters related to added vitamins, and the number of subjects with inadequate vitamin values was reduced to zero. The improved vitamin status had a positive and statistically significant effect on the delayed cutaneous hypersensitivity one of the parameters of cellular immunity. The calculation of multiple correlation after inclusion of all biochemical parameters into the stepwise regression analysis has shown that the coefficient of multiple regression between examined biochemical parameters of nutrition status and delayed cutaneous hypersensitivity was R = .599 (p less than 0.001) which indicates that about 36% of the variability in the cellular immunity would be affected by the vitamin and mineral nutrition status.

[Should dietary recommendations be revised?]. / Müssen die Ernährungsempfehlungen revidiert werden?

The dietary recommendations of the Second Swiss Nutrition Report are in part based on incomplete knowledge about nutritional patterns of the Swiss population and on controversial results of relations between nutritional status and health, thus do not fulfill completely the WHO requirements for dietary guidelines. A new set of recommendations would not be based on better knowledge. However, efforts to prevent the widespread chronical diseases, e.g. by dietary measures are understandable. We therefore recommend to apply dietary guidelines never without considering their controversial incomplete scientific basis and to prevent by this a possible negative impact of dietary guidelines.

Preventive potential of antioxidative vitamins and carotenoids on cancer.

Epidemiological and experimental research indicated some time ago that vitamins might act as protective agents in carcinogenesis. However, only more recently prospective studies proved a significant inverse correlation between certain vitamins and cancer at different site. The Basel Study (comprising 3756 healthy adult volunteers) is unique in its immediate measurement of the plasma vitamins at the time of the clinical assessment (1971-1973). The complete mortality follow-up allows testing of several hypotheses regarding the molecular basis of cancerogenesis. Among these mechanisms, aggressive oxygen species have been implicated. By analyzing plasma concentrations of essential antioxidants in cancer cases and survivors, we demonstrated a significantly negative inverse correlation between plasma beta-carotene and all cancer (n = 102, p less than .01), cancer of the lung (n = 37, p less than .01) and stomach (n = 17, p less than .05). Low retinol was related only to gastric cancer (p less than .01); low vitamin C and low vitamin E was related to all cancer and gastric cancer (p less than .05). The estimated antioxidant potential calculated as the molar product of vitamins C, E and beta-carotene showed a highly significant inverse correlation with all cancer and cancer of the lung and the stomach (p less than .01). These data and other newer studies strongly support the antioxidants in a role as natural inhibitors which may act on cancer initiation or promotion. Finally the convergence of results of the many epidemiological and experimental studies allow more soundly based conclusions with regard to dosage and time of vitamin intake in cancer.

Scientific basis for the estimation of the daily requirements for vitamins.

Scientific theories allow definition of the requirements of vitamins for humans, and reasonable judgements lead to recommendations for the daily dietary allowance. However, the scarceness of the available experimental data allows only for rough estimates of the requirements, and the lack of consensus between the various national and international bodies in making reasonable and normative judgments has led to a plurality of recommendations.

[Vitamin status of 11- to 17-year-old healthy adolescents. Data from a longitudinal study]. / Die Vitaminversorgung 11- bis 17jähriger gesunder Jugendlicher. Daten einer Longitudinalstudie.

In order to find out whether any age- or sex-related changes in vitamin nutrition or if any vitamin deficiencies can be detected in apparently healthy school children, blood vitamins (A, B1, B2, B6, C, and E) were determined in 111 children (54 boys and 57 girls), who took part in a longitudinal nutritional program. Most of the adolescents were examined yearly 5 times every year and afterwards two years later; at the begin of the study their age was 11 years, at the end 17 years. The results of vitamin determinations show for the most parameters age dependent changes, levels for Vitamin A, B1, and B2 becoming higher with increasing age, for Vitamin C in contrast markedly unfavorable. Using the criteria for risk for deficiency from adults a comparatively high percentage of adolescents must be considered to be at risk for deficiency (up to 30% for Vitamin B6). As this study shows partly statistically significant correlations between growth and some vitamin levels (e.g., for Vitamin A and E), age and sex related criteria for the assessment of vitamin status in adolescents should be made available. The results in general show that also in apparently healthy school-children subclinical biochemical vitamin deficiencies can be detected. This fact however, should be taken in consideration in planing and providing guidelines for an optimal nutritional program in adolescence.

Lipids, lipoproteins and alpha-tocopherol: relationship and changes during adolescence. A longitudinal study.

From May 1976 until June 1982 a longitudinal study in 54 apparently healthy Austrian schoolchildren with a mean age of 11.2 years at their first visit was performed. The aim of this study was to determine if there are any age-related changes in serum lipids, lipoproteins and alpha-tocopherol concentrations during adolescence and whether a permanent relationship between lipoproteins and alpha-tocopherol can be observed. Total cholesterol showed a significant decrease from age 11 to 14 years in boys (from 195.5 +/- 42.2 to 147.9 +/- 40.3 mg/dl) as well as in girls (from 181.9 +/- 29.7 to 144.1 +/- 23.4 mg/dl); thereafter, a slight increase could be shown. Similar changes could be observed for LDL cholesterol. No significant sex differences were found either in total or in LDL cholesterol, whereas in HDL cholesterol concentrations, a decrease in boys between 12 and 14 years (from 58.4 +/- 18.3 to 41.7 +/- 10.8 mg/dl) and an increase in girls from 13 years onwards led to significantly lower values in boys than in girls from the age of 16 years onwards. No consistent changes could be shown for alpha-tocopherol blood levels. Nevertheless, a close relationship between total cholesterol and alpha-tocopherol could be observed during all our investigations (0.4695 less than or equal to 0.7300, p less than 0.05) and, to a lesser degree, between LDL cholesterol and alpha-tocopherol. Significant correlations between alpha-tocopherol and HDL cholesterol and between alpha-tocopherol and triglycerides occurred only occasionally.

[Biochemical markers of vitamin supply]. / Marqueurs biochimiques d'apport vitaminique.

The biochemical indicators to assess the nutritional status of individuals may be divided into 4 categories: methods which measure body stores e.g. plasma vitamin C or urinary excretion of thiamine, methods related to the rate of conversion of vitamins to metabolites e.g. thiamine pyrophosphate content of blood or urinary excretion of pyridoxic acid, methods based on the coenzymatic or hormonal function of vitamin metabolites, e.g., erythrocyte transketolase in the case of vitamin B1 or plasma concentration of 1,25 dihydroxycholecalciferol in the case of vitamin D. Finally, methods derived from true biochemical impairment of the metabolism, e.g., elevated blood pyruvate in borderline vitamin B1 deficiency or prolonged blood clotting time in the case of vitamin K deficiency. The results of all of these methods are for a certain vitamin related to each other and also to the daily intake of the vitamin in question as long as the daily vitamin intake remains stationary and no confounding variables such as disease, smoking or drinking habits interfere. Otherwise the estimation of vitamin intake by measuring biochemical parameters becomes questionable, since biochemical parameters are indicators of nutritional status and not so much of nutrient intake.

The vitamin A activity of beta-carotene.

In rats (parameters: growth, epithelial protection and liver storage), and in chicks (liver storage), it has been demonstrated that the conversion of beta-carotene to vitamin A diminishes inversely to the intake of beta-carotene, as long as the dosages are higher than 1-2 times the daily requirements. The decrease in the biopotency of beta-carotene follows a Michaelis Menten kinetic. In the dosage range of the daily requirements molecular ratio applies. Based on these findings, the following guidelines for the conversion of retinol in man are proposed: (Table: see text). For beta-carotene in oily solutions, a conversion factor of 1:3.33 should be accepted for the dosage range of 1,500 to 4,000 micrograms. For higher doses, this factor should be decreased according to the results with laboratory animals: For beta-carotene in vegetables, the conversion factor of 1:6.0 should be accepted for intakes between 1,500 and 4,000 micrograms. A higher factor should be chosen for smaller intakes, and a smaller factor for higher intakes.

Cancer, vitamins, and plasma lipids: prospective Basel study.

In the Basel study (BS) (1960-73) on cardiovascular and peripheral arterial diseases, a mortality follow-up was completed for the period 1965-80. Of the 4,224 men at risk for these diseases, 531 died. The causes of death were established from the death certificates and classified into 8 groups. For each case 2 age- and sex-matched controls were selected and compared with the corresponding cases with regard to the various variables obtained at the three examinations (1960, 1965, 1971). This report dealth with cancer mortality, plasma lipids, plasma vitamins, alcohol and cigarette consumption, and intake of milk and citrus fruits. The results were all obtained at the second follow-up examination (BS III, 1971-73). Cancer of the lung, stomach, large bowel, and all other sites were treated separately. The average follow-up from BS III until death varied from 3.7 years (other sites) to 4.9 years (cancer of the lung). Of 129 cancer deaths, the highest incidence was found for cancer of the lung (38) followed by stomach (19) and large bowel, (15) and the remainder (57) was for other sites. Plasma lipids did not differ significantly among cases and controls. However, the lowest values were observed in colorectal cancer and gastric carcinoma (mean cholesterol, 213 mg/dl). beta-Carotene was significantly lower in cancer cases of the lung than in controls (14.8 micrograms/dl vs. 23.7; P less than .05). It was also low in gastric cancer cases (13.0 micrograms/dl). Vitamin A was below average only in cases with gastric cancer (difference due to the small number not significant). Vitamin C was consistently lower in cancer cases than in controls. The lowest value was found for cancer of the stomach and corresponded to a below-average consumption of citrus fruits. Vitamin E was low in cancer of the colon. Plasma lipids correlated strongly with vitamin E (tau = 0.5) and to a lesser extent with vitamin A (tau = 0.25). beta-Carotene correlated poorly with beta-lipoproteins (low-density and very low-density lipoproteins) but significantly with total cholesterol. Smoking was inversely related, as was alcohol consumption, to the beta-carotene level. From these results, the conclusion was that vitamins influence carcinogenesis in humans.

[Caloric value of food and coverage of the recommended nutritional intake of vitamins in the adult human. Principle foods containing vitamins]. / Valeur calorique del l'alimentation et couverture des apports nutritionnels conseillés en vitamines del l'homme adulte. Principaux vecteurs alimentaires de vitamines.

Two daily food consumption models were defined. One of them (I) is representative of the French eating habits, the other (E) of a diet with a theoretically balanced content of macronutrients for a caloric intake of 2,500 kcal. For each of these two models, four menus were calculated to obtain four caloric levels (1,500, 2,000, 2,500 and 3,000 kcal). The vitamin content of these menus was established on the basis of the literature (food composition tables). Nutritional losses resulting from usual cooking methods were taken into account. The results show that the dietary intake of some vitamins, such as folic acid, pantothenic acid, vitamin A, beta-carotene, vitamin C and B1, was likely to be inadequate and are in agreement with those of epidemiologic surveys carried out in developed countries. The threshold of 80% of the recommended allowances is not reached with a caloric level of 2,500 kcal (balanced diet) or 2,700 kcal (unbalanced diet). For an allowance of 1,500 kcal, most of the vitamins do not reach or just reach 50% of the recommended level. This result shows that the former eating habits of the French population, whose caloric intake was high (more than 3,000 kcal), were correct as they covered the recommended intakes of micronutrients. This work corroborates the great importance of some food groups in covering the recommended vitamin intakes and underlines the necessity of diversifying food.