Serum zinc changes due to iron supplementation in teen-age pregnancy.

Serum zinc and iron concentrations in a group of pregnant teen-agers supplemented with a multivitamin were compared during pregnancy with a group supplemented with a multivitamin containing 18 mg Fe. Serum measurements were at 13 wk of gestational age (prestudy) and during supplementation at 20, 32, and 38 wk, delivery, and 4 and 12 wk postpartum. Hematocrit measurements were used to adjust the measured metal concentrations for the diluting effect of the normal blood-volume increase. The non-Fe-group mean, adjusted serum Zn concentrations showed no change, but the serum Fe decreased to 28% below prestudy concentrations at 38 wk. In contrast, the Fe-supplementation group showed a progressive increase in Fe concentrations to a maximum of 38% above prestudy concentrations at 4 wk postpartum and a 35% decrease from prestudy Zn concentrations during the third trimester. The results of this study suggest that 18 mg Fe/d is adequate supplementation for nonanemic teen-age pregnancy and depresses the serum Zn concentration.

Relationship of metal metabolism to vascular disease mortality rates in Texas.

The annual mortality rates for 1968 of six types of cardiovascular diseases among those persons over 45 years of age in 24 Texas communities were compared with respective community drinking water and urine metal levels of calcium, magnesium, potassium, lithium, strontium, and silicon. Numerous inverse correlations were found between mortality rates and the levels of various metals in both drinking water and urine. Positive correlations were also observed between several of the mortality rates and the ratio of the concentration of sodium to that of the other metals in both water and urine. Mean community urinary levels of lithium, magnesium, strontium, and silicon showed a direct correlation to the levels of exposure via the drinking water. The results of this study suggest that calcium, magnesium, lithium strontium, and silicon may protect against cardiovascular mortality; possibly, by competing with sodium and potassium for transport in the intestinal lumen, increasing excretion of sodium, or other mechanism.

Serum ferritin levels after multivitamin iron ingestion during teenage pregnancy.

The postabsorptive serum ferritin levels following normal dosages of prenatal multivitamin/multimineral supplements were studied in 17 pregnant teenagers, whose fetuses were between 16 and 20 weeks gestational age. The purpose of the study was to determine the effect of a single oral dose of differing prenatal multivitamin/multimineral tablets containing 60 or 65 mg of elemental iron on the postabsorptive serum ferritin levels. Each woman was randomly tested following the ingestion of one of three different tablets, both in a fed and a fasting state. Blood samples were obtained for ferritin measurement immediately prior to ingestion of the prenatal tablet, with or without a standard meal, and at 1, 3, 6, and 8 hours postabsorption. The group mean serum ferritin levels increased dramatically during the fasting state following ingestion of the Stuart Prenatal tablet and decreased when the Stuartnatal 1 + 1 or Materna 1.60 was ingested. The opposite results were observed when the tablets were ingested postprandially. The results of the study indicate that Stuart Prenatal was most suitable for consumption while fasting (ie, at the hour of sleep), and both Stuartnatal 1 + 1 and Materna 1.60 with a meal.

Bioavailability of iron in prenatal multivitamin/multimineral supplements administered to pregnant teenagers.

Absorption of elemental iron from three single-daily-dose prenatal multivitamin/multimineral supplements was compared in bioavailability studies of subjects under fasting and postprandial conditions. Each of the supplements (Stuartnatal 1 + 1, Stuart Prenatal, and Materna 1.60) contained 60 or 65 mg of iron. The subjects, teenagers in the second trimester of pregnancy, were assigned to the fasting or postprandial conditions at intervals of three to seven days. For the postprandial condition, subjects took the supplement after eating a standardized meal that had been designed to provide a minimal amount of iron and no caffeine (which inhibits iron absorption); blood was drawn at 0, 1, 3, 6, and 8 hours. Bioavailability studies showed that all three supplements provided adequate levels (at least 3.5 mg) of absorbed iron when taken postprandially. The highest quantity of net iron transport as well as the most rapid intestinal transport in either condition was yielded by Stuartnatal 1 + 1 taken in the fasting state. In the postprandial condition, Materna 1.60 demonstrated the fastest transport time and highest net iron transport; when given to a subject in the fasting condition, however, this supplement provided less than the recommended 3.5 mg of absorbed iron. These results suggest that iron absorption is influenced by supplement formulation as well as the presence or absence of food. Considering variations in compliance when iron is to be taken on an empty stomach as well as variable absorption in the fasting state, the most reliable supplementation would appear to be achieved by instructing pregnant women to take multivitamin/multimineral supplements at mealtime.

Zinc and copper levels in premenstrual syndrome.

OBJECTIVE: To determine whether changes in peripheral zinc and copper levels are associated with symptoms of premenstrual syndrome (PMS). DESIGN: Ten PMS patients and 10 controls gave blood at 2- or 3-day intervals through three menstrual cycles. Serum zinc and copper were measured by flameless atomic absorption spectrophotometry. RESULTS: In the controls zinc values were not significantly different between the follicular and the luteal phases. In the patients, the values were significantly lower during the luteal phase than during the follicular phase. Lower levels of zinc during the luteal phase in PMS patients, compared with the controls, were noted. Copper levels were noted to be higher during the luteal phase in PMS patients compared with the controls. Because copper competes with zinc for intestinal absorption and serum protein binding sites, zinc:copper ratio can reflect the availability of zinc in the body. The computation of this ratio revealed that the ratio was significantly lower in the patients than those in the controls during the luteal phase. CONCLUSIONS: Our data suggest that zinc deficiency occurs in PMS patients during the luteal phase, and the availability of zinc in PMS patients during the luteal phase is further reduced by the elevated copper.

Apparent effect of ascorbic acid medication on semen metal levels.

The apparent effect of ascorbic acid therapy for nonspecific spermagglutination on semen levels of ascorbic acid as well as macro- and micrometals was determined in 20 men (ages 25 to 38). Pretreatment diagnosis was based on infertility and relatively low ratings in sperm density, motility, motility index, and semen volume, and were associated with large numbers of abnormal sperm, sperm precursors, and leukocytes. The pretreatment levels of ascorbic acid, sodium, iron, potassium, zinc, manganese, lead, magnesium, and copper were measured in each patient's semen and compared with levels following 60 days of dietary vitamin C supplementation (1.0 gm/day). Analysis of the vitamin C preparation prescribed revealed that each subject was given an impure ascorbic acid medication to supplement a normal diet. Therefore, the significant increases in levels of ascorbic acid and metals in semen following therapy could not be attributed to ascorbic acid alone, nor, similarly, the improved physical parameters of each subject's semen following therapy; no apparent spermagglutination and restored fertility may be due to the interaction of ascorbic acid with cations found in semen.

Vitamin A levels in premenstrual syndrome.

To determine whether changes in peripheral vitamin A levels are associated with symptoms of premenstrual syndrome (PMS), 10 PMS patients and 10 controls were studied. They gave blood at 2- or 3-day intervals through three menstrual cycles. The vitamin A was measured by fluorometry after cyclohexane extraction. In the controls, vitamin A values were 68.0 +/- 3.2 micrograms/dL (mean +/- SE) during the luteal phase and 69.8 +/- 4.2 micrograms/dL during the follicular phase. No significant changes were noted between the two values. In the patients, the values were 73.9 +/- 4.2 micrograms/dL during the luteal phase, which was not significantly different from 72.7 +/- 1.8 micrograms/dL during the follicular phase. No significant changes were noted between the controls and the patients in either the luteal or the follicular phase. Vitamin A deficiency in PMS patients was not demonstrated in our study.

Effect of ascorbic acid supplementation on the sperm quality of smokers.

OBJECTIVE: To determine the effect of ascorbic acid supplementation on the sperm quality of heavy smokers. DESIGN: Microscopic examination of semen for 1 month during supplementation with placebo or ascorbic acid at dose levels of 200 or 1,000 mg/d. SETTING: Department of Obstetrics and Gynecology, The University of Texas Medical Branch. PARTICIPANTS: Seventy-five men (20 to 35 years old) randomly divided into one of three supplementation groups: placebo, 200 mg and 1,000 mg of ascorbic acid. MAIN OUTCOME: Improvement in sperm quality as compared with presupplementation levels and between the three treatment groups. RESULTS: The placebo group showed no improvement in sperm quality. The groups receiving ascorbic acid showed improvement in sperm quality with most improvement in the 1,000-mg group. Pearson's correlation showed statistically significant relationships between the weekly group means of serum and seminal plasma ascorbic acid levels and sperm qualities. CONCLUSIONS: Ascorbic acid supplementation of heavy smokers in excess of 200 mg/d results in improved sperm quality.

A comparison of serum free estriol with spontaneous urine total estrogen and estrogen/creatinine ratio.

A mathematical comparison was made between the serum free estriol levels, the urine total estrogen, and the total estrogen/creatinine ratio in 83 pregnant women during the last trimester of pregnancy. The blood serum and spontaneous urine samples were obtained simultaneously, and each woman was sampled once. The serum estriol was measured by radioimmunoassay and the urine estrogen levels measured by the aqueous fluorometric Kober technique. The group averages of the three different measurements paralleled each other throughout the third trimester. Linear regression and correlation studies of the measured levels for each subject by the different methods were statistically significant (P less than or equal to 0.0001). The correlation factor between serum free estriol and spontaneous urine total estrogen was +0.5991, and between serum free estriol and the spontaneous urine total estrogen/creatinine ratio was +0.8086. The very high correlation between the two urine and the serum method suggest that spontaneous urine samples may be used to measure estrogen changes during pregnancy.

Protection of maternal iron stores in pregnancy.

Forty-two healthy young women, less than 16 weeks pregnant, with normal hematologic status, were selected at random to receive either a multivitamin/multimineral with 65 mg of iron or one without iron. During pregnancy and the puerperium, a full hematologic evaluation of the iron, folate and B12 status was performed. Those receiving the multivitamin without iron had significantly lower mean serum ferritin levels (P less than .05). During the study, 9 of these 21 noniron subjects (43%) failed to maintain an acceptable hemoglobin level (greater than 11.0 g/dL) and were medicated with 110 mg ferrous iron daily. Use of the multivitamin/multimineral supplement with iron during pregnancy and for 12 weeks postpartum maintained maternal iron stores, eliminated the need for additional iron medication and prevented the development of iron deficiency anemia. This 36-week longitudinal evaluation demonstrated the need for iron supplementation during pregnancy and for three months postpartum. Measurements of serum ferritin at 16-20 weeks of pregnancy will detect hematologic risk in young pregnant women not identified by usual hematologic assessments. The results of this study show that adequate maternal iron stores during pregnancy and the puerperium cannot be maintained by prevailing dietary patterns and therefore that iron supplementation is essential.

Amniotic fluid amino and nucleic acid in normal and neural tube defect pregnancies. A comparison.

OBJECTIVE: To explore the relationship between fetal amino acids (AAs), which are the components of structural proteins and nucleic acids, and the changes associated with neural tube defects (NTD). STUDY DESIGN: Ten weekly amniotic fluid (AF) samples from normal pregnancies (non-NTD) and 10 from NTD pregnancies between 16 and 20 weeks' gestational age were analyzed for AAs, and the weekly average for the non-NTD and NTD groups was determined. The group mean levels were compared by ANOVA. RESULTS: The weekly group mean levels of methionine, serine and aspartic acid were significantly lower than the weekly group mean levels of the other AAs. The group mean levels of methionine were significantly lower for NTD than for non-NTD pregnancies. CONCLUSION: The mean methionine level in NTD pregnancies was the only AA alteration in NTD. Although the AF levels of the non-NTD pregnancies showed that the levels of serine, aspartic acid and methionine were 3- to 19-fold lower than those of the other AAs, only methionine is essential. Consequently, methionine is rate limiting with respect to the role of structural proteins and nucleic acids in the fetus.

Iron in prenatal multivitamin/multimineral supplements. Bioavailability.

OBJECTIVE: To determine the effect of the differences in the content of essential and nonessential ingredients and of a standardized meal on iron bioavailability from four popular prenatal multivitamin/multimineral supplements. STUDY DESIGN: Iron absorption during an eight-hour period following ingestion of a multivitamin/multimineral formulation, both fasting and postprandial, after a standardized meal, was measured in five groups of 20 pregnant women (24-32 weeks of gestation) and statistically compared. The prenatal formulations were Natalins Rx, Prenatal 1/1, Stuartnatal Plus and Prenate 90. One-A-Day (without iron) was included in the study for the control group. RESULTS: The descending order of absorption, both fasting and postprandial, were Prenate 90, Stuartnatal Plus, Prenatal 1/1 and Natalins Rx. Total iron absorption for each formulation group during the postprandial phase was higher than during the fasting phase. However, the net amount of iron absorption (in both the fasting and postprandial phases) from three of the four formulations (Stuartnatal Plus, Prenatal 1/1 and Prenate 90) provided the minimal 3.0 mg of supplemental iron per day recommended by the National Academy of Science. CONCLUSION: The observed differences in iron absorption between prenatal supplements apparently reflect the effects of the various combinations of vitamins, essential minerals and additives. The absolute amount of elemental iron contained in a prenatal multivitamin/ multimineral formulation does not ensure availability.

Bioavailability of iron in two prenatal multivitamin/multimineral supplements.

OBJECTIVE: To determine the iron bioavailability in two popular prenatal multivitamin/multimineral supplement tablets containing 27 mg elemental iron. STUDY DESIGN: Iron absorption during an eight-hour period following ingestion of a multivitamin/multimineral formulation, both fasting and with a standardized meal, was measured in a group of 30 pregnant women (24-32 weeks of gestation) and statistically compared. The prenatal formulations were Stuartnatal Plus and Materna (Wyeth-Ayerst Pharmaceuticals, Philadelphia, Pennsylvania), and each contains 27 mg of elemental iron. A placebo was included in the study for the control group in this crossover, single-blind study. RESULTS: The net iron bioavailability (mean +/- SE) of Stuartnatal Plus and Materna, accounting for diurnal variation, and the iron ingested with the standardized meal was 5.4 +/- 0.4 and 4.6 +/- 0.2 mg, respectively, while fasting and 2.9 +/- 0.4 and 2.7 +/- 0.4 mg, respectively, postprandially. The total amount of iron absorption in the fasting states from both prenatal formulations exceeded the 3 mg of supplemental iron absorption per day recommended by the National Academy of Sciences. CONCLUSION: The results of this study indicate that these two prenatal multivitamin/multimineral formulations provide > 3.0 mg of supplemental iron absorption (fasting) as recommended by the National Academy of Sciences and 2.7 mg of iron absorption above the levels achieved following ingestion of a standard, low-iron test meal.

The apparent effect of iron supplementation on serum selenium levels in teenage pregnancy.

Numerous studies have suggested a significant role of selenium in the prevention of gynecological carcinoma. These were epidemiological and prospective in humans and therapeutic in laboratory animals. However, no studies have been reported regarding the normal serum selenium levels during pregnancy. The maternal total blood volume increases 30-50% during the second and third trimesters, resulting in lower measured serum levels for those metabolites, which are not increased significantly during pregnancy. A longitudinal study of the serum selenium levels in teenage pregnancy during the last two trimesters and 3 mo postpartum showed progressive elevation from 49 +/- 7 microg/dL after the 32nd week of pregnancy to 114 +/- 7 microg/dL at term, which was statistically significant (p < or = 0.001). Prenatal supplementation with 18 mg of iron per day prevented this elevation. The results of this study suggest that serum selenium levels in women normally double during pregnancy and this doubling is prevented by the minimal daily supplementation of 18 mg of iron, which may be due to increased absorption of selenium into the erythrocytes and incorporation into the glutathione peroxidase enzyme.

Comparison of sperm viability with seminal plasma metal levels.

This study compares the semen levels of lead (Pb), cadmium (Cd), and aluminum (Al) in relation to live sperm in semen samples from 64 apparently healthy men. The measured levels were separated into live sperm count tertiles (<25% [18 subjects], 25-50% [26 subjects], and >50% [20 subjects]). The mean +/- SD for each group was calculated, and the difference between the means of the high and low tertiles were compared by ANOVA. Significant differences were observed between the high and low live sperm groups for Pb (p < 0.01) and Al (p < 0.05), but not Cd. Spearman's rank correlation between sperm viability and the semen plasma metal levels showed a direct relation to Mg (p < 0.05). However, there was an inverse relation to lead (p < 0.001), cadmium (p < 0.01), and aluminum (p < 0.01). There was no significant correlation between Ca and Zn. Linear regression between the live sperm counts and semen level of the three metals show that metal levels were inversely correlated with the percentage of live sperm (p < 0.001, < 0.01). Apparently, the presence of these metals in the environment and in seminal plasma exerts a toxic effect on sperm.

Blood cell lead, calcium, and magnesium levels associated with pregnancy-induced hypertension and preeclampsia.

This study compares the red blood cell (Rbc) levels of lead (Pb), calcium (Ca), and magnesium (Mg) in relation to blood pressure in 39 pregnant women in the third trimester of pregnancy. The study population included 20 women with normal pregnancies, 15 with mild hypertension, and 4 with severe hypertension and preeclampsia. The mean +/- SD for each group was calculated and the difference between the means of the normotensive and the other groups were compared by analysis of variance. Significant differences from normal to the preeclamptic pregnancies were in (1) elevated Rbc Pb (p < or = 0.001), (2) lower Rbc Ca (p < or = 0.001), and (3) lower Rbc Mg/Pb ratio (p < or = 0.0001). Pearson's rank correlation between blood pressure showed a direct relation to the Rbc Pb level (p < or = 0.01) and an inverse relation to the Rbc Ca and Mg/Pb ratio (p < or = 0.004, < or = 0.007). Apparently, prenatal blood pressure is directly proportional to Rbc Pb content and related or modified by Rbc Ca and Mg.

Seminal plasma trace metal levels in industrial workers.

This study compares the seminal plasma trace metal levels of hospital workers with groups of industrial workers in a petroleum refinery, smelter, and chemical plant. The metals measured were the essential metals (copper, zinc, nickel, cobalt, and manganese) and the toxic metals (lead, cadmium, and aluminum). The group mean +/- SE metal level for each group (50 subjects per group) was calculated, and the statistical significance of the group mean differences of the industrial groups with the hospital group (control) was determined by the Student's t-test. The differences observed in the smelter group were increased copper and zinc (p < or = 0.001) and decreased nickel, cobalt, and manganese (p < or = 0.001, < or = 0.01). The refinery group differences were increased copper, zinc, and nickel (p < or = 0.001) but decreased cobalt and manganese (p < or = 0.001). The chemical group differences were increased zinc (p < or = 0.001) and decreased cobalt (p < or = 0.001). The seminal plasma levels of the toxic metals lead and aluminum were increased in each of the industrial groups (p < or = 0.001). Concurrent differences were (1) decreased accumulation of nickel, cobalt, and manganese in the smelter group, (2) decreased cobalt and manganese in the refinery group, and (3) only decreased cobalt in the chemical group.

Third-trimester amniotic fluid metal levels associated with preeclampsia.

Studies of maternal amniotic fluid and serum at delivery have revealed the presence of toxic metals or deficiencies of essential metals associated with high-risk pregnancy. Essential and toxic metal levels were studied in 29 preeclamptic and 101 normal pregnancies. The authors grouped the samples according to the following gestation ages: 33-36 wk (48 normal and 10 preeclamptic) and 37-40 wk (53 normal and 19 preeclamptic). The metals studied were calcium, magnesium, zinc, selenium, copper, cadmium, and lead. Comparisons of the 33-36-wk gestation group showed significant differences between normal and preeclamptic amniotic fluid in levels of lead, calcium, magnesium, zinc, and selenium. There were also significant differences in levels of magnesium, copper, zinc, cadmium, and lead during the gestation period of 37-40 wk. The changes observed in calcium and lead levels were consistent with the results of animal studies in which investigators have found depressed calcium transport associated with subacute or chronic lead poisoning, resulting in a physical syndrome similar to preeclampsia.