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Biomedical subjects

R M Ortega

Publications and source records attributed to R M Ortega.

At least 37 records · Page 2Linked to original sources
PubMed1999

Riboflavin levels in maternal milk: the influence of vitamin B2 status during the third trimester of pregnancy.

OBJECTIVE: The aim of the present investigation was to study the relationship between riboflavin status during the third trimester of pregnancy and levels of this vitamin in transition milk (days 13 to 14 of lactation) and mature milk (day 40 of lactation). METHODS: The pregnancies and lactation periods of 57 healthy women between 18 and 35 years of age (27+/-3.7 years) were monitored, vitamin intake during the third trimester was determined by recording the consumption of foods over five days and by registering the quantities provided by dietary supplements. Riboflavin status during this stage of pregnancy was determined via the measurement of the activation of erythrocyte glutathione reductase (EGR) by flavine adenine dinucleotide (FAD). Milk riboflavin levels were determined by fluorometry. RESULTS: Those subjects with riboflavin intakes below recommended (1.6 mg/day) (Group L) showed lower consumption of milk products (305.2+/-88.5 g/day) than did those with greater intakes (Group H) (507.9+/-137.2 g/day). The consumption of riboflavin containing supplements was very low and was seen only in two H subjects. Transition and mature milk riboflavin levels were significantly higher in H subjects (948.1+/-700.1 nmol/L for transition milk and 993.8+/-436.6 nmol/L for mature milk) than L subjects (574.9+/-258.7 nmol/L for transition milk and 725.4+/-254.3 nmol/L for mature milk). Subjects with alpha-EGR coefficients over 1.2 in the third trimester showed significantly lower mature milk riboflavin levels (704.1+/-241.8 nmol/L) than did subjects with more satisfactory alpha-EGR coefficients (996.4+/-302.9 nmol/L). CONCLUSION: The influence of maternal vitamin B2 status during pregnancy on breast milk riboflavin levels was confirmed.

Adolescent↗
PubMed1999

Influence of calcium intake on gestational hypertension.

Calcium intake during the third trimester of pregnancy was determined in 82 pregnant women by recording the consumption of foods over a 5-day period and by calculation of the quantity of this element provided by dietary supplements. For each subject, blood pressures were measured once per week using an aneroid sphygmomanometer, to detect and analyze differences in calcium intake between those with normal blood pressure and those suffering from gestational hypertension (7.3%). Calcium intake was significantly lower amongst subjects with high blood pressure (757.7 +/- 154.5 compared to 986.4 +/- 502.3 mg/day in normotensive subjects). The relationship between calcium intake and blood pressure was independent of other variables such as body mass index, number of previous pregnancies, weight gain, subject age or hematocrit levels. Though further investigation is needed, the results obtained seem to support the idea that pregnant women should try to maintain an optimal calcium intake.

Adolescent↗
PubMed1998

[Supplementation with iron and folates during gestation: influence on the zinc status in the mother and on the zinc content in the maternal milk].

BACKGROUND: The aim of the present study was to investigate whether such supplementation impairs the zinc status of pregnant women or the zinc content of maternal milk. MATERIAL AND METHODS: Fifty seven women were studied during pregnancy and lactation. Zinc, iron and folate intakes were monitored during the third trimester of pregnancy using a five day food record and by registering intake of the same in the form of dietary supplements. Zinc levels were determined, using flame-atomic-absorption spectrophotometry, in serum during the third trimester of pregnancy, in transition milk (day 13-14 of lactation), and in mature milk (day 40 of lactation). RESULTS: 1.8% of pregnant women took zinc supplements whilst 7% took folate supplements. However, 100% of subjects showed zinc intakes (the sum of dietary and supplementary intakes) lower than those recommended. 87.7% showed the same for folate intake, 29.8% of pregnant women took iron supplements. When dietary and supplementary intakes were added, 26.3% of subjects showed iron intakes of over 200% of those recommended. Pregnant women with iron intakes in the third trimester of pregnancy of over 200% those recommended, showed lower serum zinc levels during the third trimester and, at a later date, lower mature milk zinc levels than did subjects with lower iron intakes. CONCLUSIONS: The combined dietary and supplementary intake of iron in some subjects provided total intakes of over 200% those recommended. Though this might be associated with an improvement in iron status it may impair those of zinc. Subjects with an intake of iron of over 200% of that recommended showed significantly lower serum and mature milk zinc levels than did those with lower iron intakes. It is suggested that the nutritional status of pregnant women should be carefully monitored and supplementation tailored to the needs of each individual.

Adolescent↗
PubMed1998

Ascorbic acid levels in maternal milk: differences with respect to ascorbic acid status during the third trimester of pregnancy.

The aim of the present investigation was to study the relationship between ascorbic acid status during the third trimester of pregnancy and levels of this vitamin in transition milk (days 13-14 of lactation) and mature milk (day 40 of lactation). To this end, the pregnancies and lactation periods of fifty-seven healthy women between 18 and 35 years of age (27 (SD 3.7) years) were monitored. Vitamin intake during the third trimester was determined by recording the consumption of foods over 5 d, and by registering the quantities provided by dietary supplements. Ascorbic acid levels in maternal serum during this stage of pregnancy, and in transition and mature milk samples, were determined by spectrophotometry. Those subjects with ascorbic acid intakes below that recommended (80 mg/d) (group L) showed lower consumption of fruit and vegetables than did those with greater intakes (group H). The consumption of ascorbic acid supplements was very low, and was only seen in three group H subjects. The difference in ascorbic acid intake was reflected at serum level. Group L subjects showed significantly lower serum values than did group H subjects (30.1 (SD 36.3) mumol/l compared with 101.1 (SD 168.1) mumol/l). Vitamin intake also influenced the composition of transition milk. Group L subjects showed significantly lower levels of ascorbic acid in milk than did group H subjects (255.5 (SD 220.3) mumol/l compared with 437.8 (SD 288.4) mumol/l). The results of the present study reveal the need to increase the consumption of fruits and vegetables during pregnancy and to monitor maternal ascorbic acid intake and vitamin C status.

Adolescent↗
PubMed1998

Calcium levels in maternal milk: relationships with calcium intake during the third trimester of pregnancy.

The aim of the present study was to investigate the relationship of Ca intake and serum Ca levels during the third trimester of pregnancy with levels of the same mineral in transition milk (days 13-14 of lactation) and mature milk (day 40 of lactation). The study subjects were a group of fifty-seven healthy, lactating mothers aged between 18 and 35 years (mean 27 (SD 3.7) years) whose pregnancies and labour were attended by the Department of Obstetrics and Gynaecology of Cuenca INSALUD Hospital, Spain. Ca intake during the third trimester was determined by recording the consumption of foods over a 5 d period and by registering Ca provided by dietary supplements. The same method was used to investigate the intake of protein, vitamin D, fibre and Fe, nutrients that could affect the use of dietary Ca. Ca levels in maternal serum during this stage of pregnancy, during lactation and in transition and mature milk samples, were determined using 2-cresolphthalein complexone. During pregnancy 70.2% of subjects showed Ca intakes below 1100 mg/d (75th percentile). The consumption of Ca supplements was very small and hardly modified the mean quantity supplied by the diet. Subjects with an intake < 1100 mg/d showed no fall in Ca levels in serum, either during pregnancy or lactation, nor were decreased levels found in transition milk. However, these subjects showed lower Ca levels in mature milk (5.95 (SD 1.56) mmol/l) than did subjects with greater Ca intakes (6.82 (SD 1.31) mmol/l). This may suggest that breast-fed babies of mothers with lower Ca intakes during pregnancy also receive less Ca.

Adolescent↗
PubMed1998

The importance of breakfast in meeting daily recommended calcium intake in a group of schoolchildren.

OBJECTIVE: To evaluate the breakfast intake of calcium and milk products and to determine whether these correlate with total intake of both calcium and milk products. METHODS: Food taken at breakfast and throughout the day was recorded using a 7 consecutive day food record in 200 schoolchildren aged between 9 and 13 years. RESULTS: 65.3% of boys and 80.5% of girls showed intakes of calcium which were lower than recommended. Milk products were the foods most frequently included in breakfast (95.5% of subjects included them in this meal). A relationship was seen between energy provided by breakfast and the quantities of milk products (r = 0.5735) and calcium (r = 0.6908) taken at this meal. A relationship was also seen between energy provided by breakfast and daily intake of milk products (r = 0.4633) and calcium (r = 0.4954). The percentage of intakes of calcium lower than those recommended decreased when breakfast provided > or = 20% of total energy intake, and when the consumption of milk products at breakfast was greater than the 50th percentile (200 ml). Subjects with breakfast milk product intakes > or = 200 ml showed higher intakes of the same over the rest of the day (233.3 +/-140.4 g) than did those who took lesser quantities of these foods at breakfast (161.5 +/- 100.6 g). Further, those who took > or = 25% of the recommended intake of calcium at breakfast showed greater intakes of the same over the rest of the day (600.4 +/- 213.8 mg compared to 510.8 +/- 200.7 mg in subjects with lower calcium intakes). CONCLUSIONS: The intake of milk products (r = 0.7587) and calcium (r = 0.7223) at breakfast correlates with the consumption of these foods in the whole diet. However, the total daily intake of milk products and calcium does not depend solely on breakfast intake. Subjects with the greatest intakes at breakfast also showed greater intakes over the rest of the day (r = 0.3953 for milk products and r = 0.4122 for calcium).

Adolescent↗
PubMed1998

The influence of smoking on vitamin C status during the third trimester of pregnancy and on vitamin C levels in maternal milk.

OBJECTIVE: The aim of the present investigation was to determine the differences in vitamin C status of 57 Spanish women smokers (S) and nonsmokers (N) in their third trimester of pregnancy, and the concentrations of vitamin C in their milk. METHODS: Vitamin C intake during the third trimester was determined by recording the consumption of foods over a 5-day period (including a Sunday) and by registering vitamin C provided by dietary supplements. Vitamin C levels in maternal serum during this stage of pregnancy and in transition (days 13 to 14 of lactation) and mature milk (day 40 of lactation) were determined colorimetrically. Subjects also answered a questionnaire on their smoking habits during pregnancy. RESULTS: S subjects (n = 16) showed a lower intake of fruits, vegetables and vitamin C than did N subjects (n = 41), though these differences were not significant (17.1% of N subjects and 31.2% of S subjects took less than 80 mg of vitamin C per day). Neither were any differences found between the two groups in serum vitamin C levels. However, N subjects showed significantly greater vitamin C levels in both transition and mature milk (431.6 +/- 296.5 mumol/L and 496.1 +/- 325.6 mumol/L, respectively for N subjects, and 233.7 +/- 202.9 mumol/L and 241.3 +/- 293.1 mumol/L for S subjects). Further investigations are necessary to determine the clinical consequences of these observations, though it is already known that maternal smoking favors peroxidation events in newborn infants. CONCLUSIONS: If the concentration of antioxidants (vitamin C) in smokers' breast milk is also lower, this might aggravate the peroxidation problems of their newborn.

Adult↗
PubMed1998

Influence of smoking on vitamin E status during the third trimester of pregnancy and on breast-milk tocopherol concentrations in Spanish women.

Concentrations of antioxidants in breast milk probably define the degree of protection it can offer against peroxidation. The aim of the present investigation was to determine the differences in vitamin E status of Spanish women smokers and nonsmokers in their third trimester of pregnancy and the concentrations of tocopherol in their milk. Vitamin E intake was determined during the third trimester of pregnancy by using a 5-d dietary record (including a Sunday) and by recording the quantities provided by supplements. HPLC was used to determine vitamin E concentrations in subjects' serum during the third trimester, in transitional breast milk on days 13-14 of lactation, and in mature breast milk on day 40 of lactation. Subjects also answered a questionnaire about their smoking habits during pregnancy. Subjects were grouped as nonsmokers (71.9%; n = 41) or smokers (28.1%; n = 16). Although vitamin E intake was somewhat greater in nonsmokers, the difference was not significant. Ratios of vitamin E to polyunsaturated fatty acids were practically the same in both groups. The use of vitamin E supplements was limited and did not modify the results of the study. No significant differences in these serum indexes were found between smokers and nonsmokers, and no subject had deficient serum vitamin E concentrations. However, vitamin E concentrations in mature milk were significantly lower in smokers than in nonsmokers. Although it is already known that maternal smoking favors peroxidation events in newborns, if the concentration of antioxidants (vitamin E) in smokers' breast milk is also lower, it might aggravate the peroxidation problems of their newborns.

Adult↗
PubMed1998

Is obesity worth treating in the elderly?

Obesity is associated with a range of health problems and affects an increasing number of people. However, the body mass index (BMI) that is associated with minimum mortality increases with age. Therefore, when a bodyweight loss programme is initiated, the possible benefits should be carefully measured against the potential risks. Elderly people with severe obesity, or those who have associated health risks such as hypertension or diabetes mellitus, are in greatest need of bodyweight control. The use of drugs may be advisable in some individuals, but the treatment duration should be short and administered under strict supervision. Many studies have shown that habitual, moderate physical activity and dietary improvement (i.e. moderating fat intake, avoiding micronutrient deficiencies and increasing fibre consumption) can be useful in achieving bodyweight control in the elderly. These measures are especially effective in improving nutritional status and may therefore be recommended in elderly individuals.

Aged↗
PubMed1998

Difference in the breakfast habits of overweight/obese and normal weight schoolchildren.

The aim of the present study was to analyse the differences between the breakfast habits of obese/overweight (O) (those with body mass index [BMI] above the 75th percentile) and normal weight schoolchildren (N) (those with BMI equal to or below the 75th percentile). A seven consecutive days "food record" was used to record the intake of foods at breakfast and throughout the rest of the day. O subjects, and in particular female O subjects, omitted breakfast more frequently and took significantly smaller quantities of cereals than did N subjects. The energy supplied by breakfast, measured as a percentage of energy expenditure, was significantly lower in O subjects (17.0 +/- 8.5% in males and 14.6 +/- 6.1% in females) than in N subjects (20.9 +/- 9.4% in males and 17.6 +/- 6.5% in females). With respect to the energy and nutrients supplied by breakfast, O subjects took lower quantities of carbohydrates, thiamin, niacin, pyridoxine, vitamin D and iron than did N subjects. The energy profiles of O subjects breakfasts were more imbalanced than those of N subjects. A significant difference was seen between the amounts of energy supplied by carbohydrates. Without doubt, O subjects have less satisfactory breakfast habits than N subjects. This might be a reflection of whole diet that is less adequate, however, it is possible that an inadequate breakfast contributes to the making of poor food choices over the rest of the day, and, in the long term, to an increased risk of obesity.

Adolescent↗
PubMed1998

The influence of meat consumption on dietary data, iron status and serum lipid parameters in young women.

In a group of 130 women of fertile age (24.5 +/- 2.7 years), the consumption of meat and meat products was evaluated in order to determine the effect of this food group on blood and biochemical parameters that act as indicators of iron status, and on a range of serum lipid parameters that indicate cardiovascular risk. Food intake was monitored using a "Food Record" for seven days, including a Sunday. Subjects were divided into two groups: those who took > or = 100 g/day of meat (25th percentile) (high consumption--HC) (n = 102), and those with lesser intakes (low consumption--LC) (n = 28). Dietary data were adjusted to take into account differences in discrepancies in reporting between the two groups. The greater consumption of meat observed in HC subjects, despite its association with greater intakes of lipids (both in g/day and % of energy) and cholesterol (in mg/day and mg/1000 Kcal), did not seem to be related to any impairment of blood lipid profiles. Neither was it seen to be related to increased bodyweight nor raised blood pressure. It should not, therefore, bring about any increased risk of cardiovascular disease. However, the greater intake of thiamine, niacin, zinc and iron (total and haem) in HC subjects suggests that these may have a better nutritive status (with respect to certain nutrients) than do LC subjects. In relation to iron status. HC subjects showed higher levels of haemoglobin, haematocrit and mean corpuscular haemoglobin concentration (MCHC). These results show that restrictive criteria, with respect to the consumption of meat and meat products, could have negative repercussions on the nutritive status and health of certain groups within the population. In the female population, such criteria may be associated with impairment of iron status, without affording any greater level of protection against cardiovascular disease, or be of any help in the control of bodyweight.

Adult↗
PubMed1997

[Vitamin A concentration in maternal milk: the effect of intake and serum levels of vitamin A during the third trimester of pregnancy].

BACKGROUND: Breast fed newborns depend on maternal milk for their supply of vitamin A. A deficiency of this vitamin is associated with increased morbidity and mortality. The present study investigates whether the nutritional status of the mother during pregnancy conditions vitamin A levels in maternal milk. SUBJECTS AND METHOD: 57 healthy, lactating mothers aged between 18 and 35 were studied. Vitamin A intake during the third trimester of pregnancy was recorded using a 5 day dietary record (including a Sunday) and by registering nutrients supplied by supplements. Vitamin A levels in maternal serum during this stage of pregnancy and in transition milk (days 13-14 of lactation) and mature milk (day 40 of lactation) were determined using high performance liquid chromatography. RESULTS: The effect of vitamin A intake during pregnancy on maternal milk composition was particularly noticeable in mothers with intakes below recommended values. These subjects showed lower vitamin A concentrations in transition (60.9 micrograms/dl) and mature milk (47.2 micrograms/dl) than those with adequate intakes of this vitamin (90.8 micrograms/dl and 79.2 micrograms/dl, respectively). Subjects with serum vitamin A concentrations below 30 micrograms/dl (22.8%) during the third trimester of pregnancy also showed lower levels of the vitamin in mature milk (50 micrograms/dl) compared with those with higher serum levels (74.8 micrograms/dl). CONCLUSIONS: Diet and the nutritional status of vitamin A during pregnancy seem to condition concentrations of this vitamin in maternal milk. This, in turn, will affect the intake of vitamin A by the newborn. Given that deficiencies were detected both in serum and in maternal milk, the monitorization of the vitamin A levels in pregnant women is recommendable and if necessary, would be improved.

Adult↗
PubMed1997

Concern about nutrition and its relation to the food habits of a group of young university students from Madrid (Spain).

The aim of this investigation was to study the relationship between concern about nutrition and food consumption in 533 university students (112 men and 421 women), aged 21.7 +/- 2.1 years old. Fish, dairy products and fruit were consumed in quite satisfactory quantities though cereals and vegetables were consumed less frequently than recommended. Men were found to consume greater quantities of milk, meat, bread and alcoholic drinks, while women ate more fruit and vegetables than men. 35.4% of subjects said they were especially concerned about the intake of fat and cholesterol, 24.5% expressed special interest in weight control and 18.2% recorded worries about the intake of vitamins and minerals. 21.6% of subjects expressed no worries at all. Multiple regression analysis showed no differences in concern about nutrition with respect to the sex or body mass index (BMI) of subjects. However, as age increased, the number of subjects expressing no concern fell whilst worries over the quantity of vitamins and minerals in the diet increased. Worries about bodyweight were found to rise with BMI. However, amongst those who wanted to lose weight, 42.2% of women and 7.4% of men had a BMI < 20 kg/m2. These persons, already very slim (below recommended values), still wished to lose weight and could become susceptible to nutritional imbalances. Relationships between concerns and food habits were scarce. Although fat and cholesterol were a concern in theory, the consumption of foodstuffs such as meat and eggs was quite high. However, relationships were found between concern over the vitamin and mineral content of the diet and the intake of supplements, and concern over bodyweight and intake of products that aid slimming. Nutrition educators may find this information useful in the design of their messages and educational programs.

Adult↗
PubMed1997

Zinc levels in maternal milk: the influence of nutritional status with respect to zinc during the third trimester of pregnancy.

OBJECTIVE: To study the relationship between nutritional status with respect to zinc during the third trimester of pregnancy and levels of the same mineral in transition milk (days 13 and 14 of lactation) and mature milk (day 40 of lactation). DESIGN: Longitudinal study. SUBJECTS: A group of 57 healthy, lactating mothers aged between 18 and 35 y (27 +/- 3.7) whose pregnancy and labour were attended by the Department of Obstetrics and Gynaecology of Cuenca INSALUD Hospital, Spain. INTERVENTIONS: Zinc intake during the third trimester was determined by recording the consumption of foods over a five day period and by registering zinc provided by dietary supplements. Zinc levels in maternal serum during this stage of pregnancy, and in transition and mature milk, were determined by atomic absorption spectroscopy. RESULTS: During pregnancy all subjects showed zinc intakes lower than those recommended. Only one pregnant subject took a supplement that provided extra zinc (1 mg/d). Subjects with an intake of lower than 50% of that recommended (L) (43.9%) showed significantly lower serum and mature milk zinc levels than did those with higher intakes (H) (56.1%) [12.0 +/- 1.5 mumol/L and 28.7 +/- 6.2 mumol/L compared to 13.3 +/- 2.6 mumol/L and 33.1 +/- 8.0 mumol/L respectively]. 56% of L subjects and 28.6% of H subjects showed serum zinc levels of less than 12.2 mumol/L. 8% of L subjects and no H subjects showed less than 11.5 mumol/L of zinc in maternal milk. CONCLUSIONS: The diet conditions maternal serum zinc levels during pregnancy and those of milk during lactation. Though all subjects showed intakes clearly below those recommended, low levels in serum or milk were much rarer. These results support the idea that there is a need to reset the limits of normality for serum and milk zinc levels. Further work in this area may confirm that the present recommended intakes of zinc be modified.

Adolescent↗
PubMed1997

Differences in diet and food habits between patients with gallstones and controls.

OBJECTIVE: To compare the food, energy, macronutrient and micronutrient intake of patients with gallstones to those of a control group of similar demographic characteristics. DESIGN: Patient-control study. SUBJECTS: 54 gallstone patients and 46 control subjects. METHODS: Two 24-hour dietary recalls and a "food frequency intake" questionnaire were obtained from patients and controls. In both groups, the presence/absence of gallstones was confirmed by ultrasonography. Participants answered a questionnaire on their physical activity patterns. RESULTS: Gallstone patients consumed less food per day (g/day) and less fish and fruits than did control subjects. They also showed greater intakes of cereals, oils, sugars and meats than did control subjects and ate fewer meals per day, tending to omit evening snacks and more substantial evening meals. Further, patients spent less time walking and slept more than did control subjects. They also experienced fluctuations in body weight with greater frequency. Patients consumed more total calories (energy) and fats (especially monounsaturated fatty acids and saturated fatty acids), and less fiber, folate and magnesium than did control subjects. Women with gallstones were shown to have significantly higher intakes of total fats, monounsaturated fatty acids, saturated fatty acids and cholesterol, and significantly lower intakes of fiber, folate, magnesium, calcium and vitamin C than control women. For all vitamins and minerals studied, patients showed a greater percentage of intakes below those recommended. CONCLUSIONS: Dietary intervention might provide a method of avoiding the recurrence of gallstones as well as a method of prevention control subjects.

Aged↗
PubMed1997

Concern regarding bodyweight and energy balance in a group of female university students from Madrid: differences with respect to body mass index.

OBJECTIVE: There are powerful social and psychological motivators that oblige a high proportion of women to restrict their energy intake for purely aesthetic reasons. The purpose of this research was to assess the relationships between concern regarding body weight and energy balance in a group of female university students from Madrid, Spain, with respect to differences in body mass index (BMI). DESIGN: 126 subjects completed a questionnaire asking if they were happy with their body weight, if they considered themselves fat, and if they would like to lose some weight. Energy intake was measured by means of a 7-day food record. Food intake was recorded by weight, except for that consumed away from home which was recorded using traditional household quantities. A comparison of energy intake and estimated energy expenditure was performed, using equations proposed by the World Health Organization (WHO), to provide a measure of the under- or overestimation of intake. RESULTS: All subjects with BMI > or = 25 kg/m2 (6.2% of the total) described themselves as fat. 71.4% had, at some time, followed a weight-reduction diet. However, even among subjects with BMI < 20 kg/m2 (28.4% of the total), 2.9% thought themselves fat and 17.1% had at some time followed a slimming diet. This shows excessive concern over losing weight in some women. Estimated energy expenditure was similar to energy intake in subjects with BMI < 20 kg/m2. However, as BMI rose (with a corresponding increase in theoretical energy expenditure), the reported energy intake decreased. It is therefore likely that underestimation of energy intake increased with BMI (r = 0.4498). CONCLUSION: These results indicate that a large percentage of the women studied would like to lose weight until they reach, or indeed exceed, the lower limit of the acceptable normal range. This could be a danger to their health. Underestimation of energy intake was found to increase with BMI, a phenomenon that should be kept in mind when designing diet studies.

Adult↗
PubMed1997

Vitamin A status during the third trimester of pregnancy in Spanish women: influence on concentrations of vitamin A in breast milk.

We examined the relation between the vitamin A status of Spanish women during pregnancy and concentrations of vitamin A in breast milk. The subjects were 57 healthy, lactating women aged 18-35 y. Vitamin A intake was determined during the third trimester of pregnancy by using a 5-d dietary record that included a Sunday and by recording the quantities provided by supplements. HPLC was used to determine vitamin A concentrations in subjects' serum during the third trimester, in transitional breast milk (on days 13-14 of lactation), and in mature breast milk (on day 40). During the third trimester, 33.3% of subjects had vitamin A intakes from diet and supplements < 800 microg/d, the recommended value. These subjects had serum and breast milk vitamin A concentrations that were significantly lower than those of subjects who consumed greater quantities of the vitamin. Furthermore, subjects with serum vitamin A concentrations < 1.05 micromol/L during the third trimester (22.8%) had lower mean (+/- SD) concentrations of the vitamin in mature breast milk than did subjects with higher serum concentrations (1.8 +/- 1.2 micromol/L compared with 2.6 +/- 0.8 micromol/L; P < 0.05). These results show that vitamin A intake and serum vitamin A concentrations during pregnancy influence the composition of breast milk. Given that 12.3% of subjects had < 1.40 micromol vitamin A/L in mature breast milk, it seems advisable to follow and, if necessary, improve vitamin A status during pregnancy and lactation.

Adolescent↗