Objective: To assess the nutritional status for vitamins B 6 and B 12 and folate in an adult Mediterranean population, in order to identify patterns of intake, groups at risk for deficiency, and factors that might influence this risk. Design: A cross-sectional epidemiological survey. Setting: Andalusia, a western Mediterranean region in southern Spain. Subjects: The study was carried out with a random sample of 3528 subjects (1813 men, 1715 women) who were between 25 and 60 y of age. Blood samples were obtained for biochemical assays in a random subsample of 384 subjects (183 men, 201 women). Interventions: Food consumption was assessed by 48-h recall. Vitamin B 6 was measured as alpha erythrocyte aspartate aminotransferase activation coefficient (aEAST); vitamin B 12 and folate concentrations were measured in plasma. Results: Energy and vitamin intakes were significantly higher in men than in women. In men, intakes were below two-thirds of the RDA in 10.8, 2.9 and 22.6% for B 6, B 12 and folate, respectively. The corresponding figures in women were 16.7, 5.1 and 23.5% for vitamins B 6 , B 12 and folate. Age, place of residence and educational level, alcohol use and smoking were also associated with differences in the intake of these nutrients. Biochemical analyses showed that vitamins B 6 , B 12 and folate status was acceptable in 75.7, 89.1 and 57.6% of the population, respectively. Plasma concentration of folate was significantly higher in women. Conclusion: Our results provide a precise estimate of the nutritional status for vitamins B 6 , B 12 and folate in the adult population of southern Spain. Factors such as age, place of residence, level of education and smoking can increase the risk of inadequate intake of some nutrients. However, these factors did not affect biochemical indexes of nutritional status in the present study.

The aim of the present study was to assess the nutritional status for thiamin (vitamin B 1 ) and riboflavin (vitamin B 2 ) in an adult Mediterranean population, in order to identify patterns of intake, groups at risk for deficiency and factors that might influence this risk. A cross-sectional survey was carried out in Andalusia, a western Mediterranean region in southern Spain. Nutrient intakes were studied in a random sample of 3390 subjects (1746 men, 1644 women) who were between 25 and 60 years of age. Blood samples were obtained for biochemical assays in a random subsample of 372 subjects (181 men, 191 women). Food consumption was assessed by 48 h recall. Vitamin B 1 and B 2 were measured as erythrocyte transketolase and as erythrocyte glutathione reductase activation coefficients, respectively. Energy and vitamin intakes were significantly higher in men than in women. Intakes were below two-thirds of the recommended dietary allowance for vitamin B 1 in 7·80 % of the men and 4·50 % of the woman, and were below this level for vitamin B 2 in 18·00 % of the men and 11·70 % of the women. Age, educational level, alcohol use and smoking were also associated with differences in the intake of these nutrients. Biochemical analyses showed that vitamin B 1 and B 2 status was deficient in 6·40 and 5·30 % of the population, respectively. Although factors such as gender, age, level of education, drinking and smoking can have an effect on the risk of inadequate intake of these nutrients, these factors did not affect biochemical indices of nutritional status in the present study.

In previous studies based on indirect procedures, we reported that Mg deficit increased the bioavailability of a number of elements such as calcium, zinc, iron, copper, manganese and decreased selenium absorption. The present study was designed to verify these findings by direct methods. We investigated the effect of dietary magnesium deficiency on enterocyte Ca, Fe, Zn, Cu, Mn and Se concentrations. Male Wistar rats were fed a Mg-deficient diet (129 mg Mg/kg food) for 70 days. Whole enterocytes from the upper jejunum were isolated and Ca, Fe, Zn, Cu, Mn and Se were determined. The results were compared with findings in a control group that was pair-fed with an identical diet except that it covered this species's nutritional requirements for Mg (480 mg Mg/kg food). The Mg-deficient diet significantly increased enterocyte content of Ca, Fe, Zn, Cu and Mn; however, we found no significant changes in the Se content of these cells. These data support the results obtained by indirect methods.

The influence of i.m. administration to the mother of hydrocortisone acetate (doses of 0.4, 0.8 or 2.0 mg/100 g body weight/day) during the first 15 days of lactation on milk protein and lactose composition and serum levels of protein, glucose and insulin in dams and pups is studied. Total serum proteins and albumin/globulin ratio in dams were unchanged by treatment. The daily injection of 0.4 or 0.8 mg/100 g body weight failed to alter serum levels of glucose or insulin in dams, whereas a dose of 2.0 mg/100 g body weight led to a rise in glucemia (from 118 +/- 3.2 to 133 +/- 5.3) which was accompanied by a sharp change in insulinemia (from 40.7 +/- 4.1 to 83.6 +/- 6.9). All three doses raised protein levels in milk. The smallest increase was recorded with 2.0 mg/100 g body weight; this dose also reduced milk lactose content. Total serum proteins in pups rose slightly but nonsignificantly, and no significant effects were noted on albumin/globulin ratio or serum glucose and insulin levels.

The effect of quality (casein + 5% DL-methionine, normal or heated at 180 degrees C for 20 min) and quantity (4%, 6%, 10%, 15% and 20%) of dietary protein on food intake, weight increase and nitrogen retention, has been studied in both sexes weaning Nestle rats. Our results show that food intake, when expressed as g dry matter/100 g body weight and day, is not dependent on the quality and quantity of dietary protein. Weight increase goes up at a 10% dietary protein level. At higher protein levels (15% and 20%) values are only maintained. Protein quality do not cause any difference. Nitrogen retention goes up on increasing dietary protein level, with a maximum at 10% casein-methionine and 15% heated protein, being retention heated casein-methionine significantly lower. At a higher protein level, the maximal anabolic capacity for protein is maintained. Maximum Protein Productive Value (PPV) is obtained from diets containing 10% protein level (normal or heated). There is a significant decrease at higher protein levels (15% and 20%). The PPV of heated casein-methionine is lower than PPV of normal one at 6%, 10%, 15% and 20% protein levels. The results state that in our assays, in spite of the good quality of heated casein-methionine, its metabolic efficiency is below non heated protein values even when protein contribution is increased. We can assume that protein quantity is not a balancing factor for protein quality.