Changes in the concentrations of biochemical indicators of diet and nutritional status of pregnant women across pregnancy trimesters in Trujillo, Peru, 2004-2005

Concentrations of potentially toxic metals and trace elements in pregnant women and association with birth outcomes: A cross-sectional study in Malawi

Potentially toxic metals and trace elements have been used in Malawi for a long time. However, data on exposure to these elements by susceptible groups like pregnant women and its associations with reproductive health outcomes in Malawi and southern hemisphere is limited. We investigated the concentrations of potentially toxic metals as well as trace elements in pregnant women and assessed the relationship between the levels these elements in maternal blood and sociodemographic factors, dietary habits and birth outcomes. Maternal data was collected from 605 pregnant women. Provider administered questionnaire was used to collect data on maternal sociodemographic factors, life style and immediate birth outcomes. Maternal venous blood samples were collected from 506 pregnant women in southern Malawi between August 2020 and July 2021. An inductively coupled plasma mass spectrometry (ICP-MS) technique was used to analyse maternal blood samples for concentrations of arsenic (As), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni), selenium (Se) and zinc (Zn). Maternal age emerged as the primary predictor for Cu (p = 0.023), As (p = 0.034) and Hg (p = 0.013) blood concentrations, followed by area of residence, which had significant impact on Ni (p = 0.024) and As (p < 0.001) concentrations. High maternal blood concentrations of Ni were associated with increased birth weight (p = 0.047), birth length (p = 0.026), head circumference (p = 0.029) and gestational age (p = 0.035). Negative associations were observed between maternal whole blood total arsenic (combining organic and inorganic As) concentration and neonatal birth length (p = 0.048) and head circumferences (p < 0.001). Similarly, higher maternal blood Pb concentrations were associated with smaller head circumference (p = 0.002) and birth weight (p = 0.016). This study demonstrates the need to introduce biomonitoring studies in Malawi and countries with similar settings in the global south.

A Narrative Review of Factors Associated with Skin Carotenoid Levels

Despite consistent evidence that greater consumption of fruits and vegetables (FV) is associated with significant reductions in chronic disease morbidity and mortality, the majority of adults in the United States consume less than the amounts recommended by public health agencies. As such, there is a critical need to design and implement effective programs and policies to facilitate increases in FV consumption for the prevention of these diseases. To accomplish this, an accurate, inexpensive, and convenient method for estimating the dietary FV intake is required. A promising method for quantifying the FV intake via proxy that has gained interest in recent years is the measurement of skin carotenoid levels via spectroscopy-based devices. However, there exist certain dietary and non-dietary factors that may affect the skin carotenoid levels independently of the dietary intake of carotenoids. In order to validate the ability of this method to accurately estimate the FV intake among diverse demographics, these factors must be identified and taken into consideration. Therefore, this narrative review seeks to summarize the available research on factors that may affect the skin carotenoid levels, determine current gaps in knowledge, and provide guidance for future research efforts seeking to validate spectroscopy-measured skin carotenoid levels as a means of accurately estimating the FV intake among various populations.

Perinatal plasma carotenoid and vitamin E concentrations with maternal blood pressure during and after pregnancy

BACKGROUND AND AIMS

Few studies examined the influence of carotenoids and vitamin E on blood pressure or hypertension during and after pregnancy. We related perinatal plasma concentrations of carotenoids and vitamin E (in individual forms and in combination) to blood pressure and hypertension at late pregnancy and 4 years post-pregnancy.

METHODS AND RESULTS

In 684 women of the Growing Up in Singapore Towards Healthy Outcomes cohort, we quantified plasma carotenoids and vitamin E concentrations at delivery. Systolic blood pressure and diastolic blood pressure (SBP and DBP) around 37-39 weeks' gestation were extracted from obstetric records and measured at 4 years post-pregnancy. Principal component analysis derived patterns of carotenoids (CP) and vitamin E. Associations were examined using linear or logistic regressions adjusting for confounders. Two carotenoids (CP1: α-carotene, β-carotene, and lutein; CP2: zeaxanthin, lycopene, and β-cryptoxanthin) and one vitamin E (γ-, δ-, and α-tocopherols) patterns were derived. CP1 (1SD score increment) was associated with lower SBP and DBP [β (95% CI): -2.36 (-3.47, -1.26) and -1.37 (-2.21, -0.53) mmHg] at late pregnancy> and 4 years post-pregnancy [-1.45 (-2.72, -0.18) and -0.99 (-1.98, -0.01) mmHg]. Higher β-cryptoxanthin concentrations were associated with lower SBP and DBP [-1.50 (-2.49, -0.51) and -1.20 (-1.95, -0.46) mmHg] at late pregnancy. Individual vitamin E and their pattern were not associated with blood pressure or hypertension.

CONCLUSION

Higher perinatal α-carotene, β-carotene, and lutein concentrations are associated with lower blood pressure in women at late pregnancy and post-pregnancy. Foods rich in these carotenoids, such as red-, orange-, and dark-green-colored vegetables, might be beneficial for blood pressure during and after pregnancy.

A Study to Improve the Vitamin A and Iodine Status of Pregnant Women through a Multiple Micronutrient Fortified Salt

Background. To study the efficacy of a multiple micronutrient fortified salt enriched with iron, iodine, vitamin A, vitamin B1, vitamin B2, vitamin B6, vitamin B12, niacin, and folic acid in improving serum retinol and iodine status of pregnant women. Methods. It was a randomized control trial in the antenatal clinic of a hospital. 151 women in the experimental group received a multiple micronutrient fortified salt to cook all their meals, and 150 women in the control group did not receive the fortified salt. Blood was collected in the three trimesters. Urine was collected in their first and third trimesters. Serum retinol, CRP (C-reactive protein), and AGP (Alpha glycoprotein) in blood were assessed, and iodine was assessed in urine. All the women were dewormed once. Results. The inflammation adjusted mean serum retinol in three trimesters in the experimental group was 24.51, 27.29, and 25.68 µg/dL, and it was 28.97, 27.63, and 22.72 µg/dL in the control group. Over the study period of 6 months, the increase in serum retinol in the experimental group was 1.17 µg/dL whereas in the control group serum retinol decreased by 6.25 µg/dL. The experimental group increase in serum retinol is significantly more ( $p=0.0001$ ) than the changes in retinol in the control group. The prevalence of serum retinol deficiency in the three trimesters was 39.1%,25.8%, and 37.7% in the experimental group and 14%, 22.7%, and 39.3% in the control group, and the change in the experimental group was significant ( $p=0.001$ ) compared to the control group by binary logistic regression. Over the study period of 6 months there is a significant increase in urinary iodine concentration in the experimental group ( $p=0.030$ ), showing absorption of iodine from the fortified salt whereas there is a significant decline in the iodine values in the control group ( $p=0.008$ ). At the end of the study, the urinary iodine concentration of the experimental group was significantly more ( $p=0.0001$ ) than that of the control group. Conclusion. The fortified salt was able to improve serum retinol levels and urinary iodine levels in pregnant women. Trial Registration. This trial was registered retrospectively on 19/02/2022 in the ISRCTN registry with trial ID ISRCTN17782574.

Maternal Blood Levels of Toxic and Essential Elements and Birth Outcomes in Argentina: The EMASAR Study

Pregnant women’s levels of toxic and essential minerals have been linked to birth outcomes yet have not been adequately investigated in South America. In Argentina, n = 696 maternal whole blood samples from Ushuaia (n = 198) and Salta (n = 498) were collected in 2011–2012 among singleton women at 36 ± 12 h postpartum and analyzed for blood concentrations of arsenic (As), cadmium (Cd), mercury (Hg), lead (Pb), copper (Cu), manganese (Mn), selenium (Se) and zinc (Zn). This study examined the associations between maternal elements levels and birth outcomes, and sociodemographic factors contributing to elements levels. Maternal age, parity, body mass index, smoking, and education were linked to concentrations of some but not all elements. In adjusted models, one ln-unit increase in Pb levels was associated with increased gestational age (0.2 weeks, 95% CI = 0.01–0.48) and decreased birth weight (−88.90 g, 95% CI = −173.69 to −4.11) and birth length (−0.46 cm, 95% CI = −0.85 to −0.08) in the Salta sample. Toxic elements concentrations were not associated with birth outcomes in Ushuaia participants. Birth outcomes are multifactorial problems, and these findings provide a foundation for understanding how the body burden of toxic and essential elements, within the socioeconomic context, may influence birth outcomes.

Plasma Concentrations and Maternal-Umbilical Cord Plasma Ratios of the Six Most Prevalent Carotenoids across Five Groups of Birth Gestational Age

Carotenoids are antioxidant nutrients with the potential to provide protection against oxidative stress. Plasma carotenoid concentrations are lower in newborn infants compared to their mothers; however, limited information is available regarding how concentrations differ by gestational age. The objective of this research is to assess maternal and umbilical cord plasma carotenoid concentrations and maternal-umbilical cord plasma ratios across five groups of birth gestational age. Mother-infant dyads were enrolled at delivery for collection of maternal and umbilical cord blood. Plasma carotenoids were analyzed by HPLC and LC-MS/MS. Birth gestational age was categorized into five groups, and the Kruskal–Wallis test compared carotenoid concentrations and maternal-umbilical cord plasma ratios between these groups. A p-value of < 0.05 was considered statistically significant. 370 mother-infant dyads were included, with most infants delivered at early term (20.3%) or term (64.6%). Though maternal plasma concentrations increased with birth gestational age, we observed less variability in umbilical cord plasma concentrations, thus the maternal-umbilical cord plasma ratio also increased with birth CGA groups for lutein + zeaxanthin (p = 0.008), β-cryptoxanthin (p = 0.027), α-carotene (p = 0.030); β-carotene approached significance (p = 0.056). Additional research is needed to determine if carotenoid concentrations were physiologic to varying gestational ages or if they were impacted by factors associated with preterm birth.

Maternal Lutein and Zeaxanthin Concentrations in Relation to Offspring Visual Acuity at 3 Years of Age: The GUSTO Study

Lutein and zeaxanthin play important roles in visual functions, but their influence on early visual development is unclear. We related maternal lutein and zeaxanthin concentrations during pregnancy to offspring visual acuity (VA) in 471 mother–child pairs from the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort. Maternal concentrations of plasma lutein and zeaxanthin were determined at delivery. We measured uncorrected distance of VA in 3-year old children using a LEA Symbols chart; readings were converted to the logarithm of Minimum Angle of Resolution (logMAR), with >0.3 logMAR indicating poor VA. Associations were examined using linear or Poisson regression adjusted for confounders. The median (inter-quartile range) of maternal lutein and zeaxanthin concentrations were 0.13 (0.09, 0.18) and 0.09 (0.07, 0.12) µmol/L, respectively. A total of 126 children had poor VA. The highest tertile of maternal zeaxanthin concentration was associated with 38% lower likelihood of poor VA in children (95% CI: 0.42, 0.93, p-Trends = 0.02). Higher maternal lutein concentrations were associated with a lower likelihood of poor VA in children (RR 0.60 (95% CI: 0.40, 0.88) for middle tertile; RR 0.78 (95% CI: 0.51, 1.19) for highest tertile (p-Quadratic = 0.02)). In conclusion, lutein and zeaxanthin status during pregnancy may influence offspring early visual development; but the results require confirmation with further studies, including more comprehensive measurements of macular functions.

Nutritional Gaps and Supplementation in the First 1000 Days

Optimized nutrition during the first 1000 days (from conception through the 2nd birthday) is critical for healthy development and a healthy life for the newborn. Pregnancy and the postpartum period are accompanied by physiological changes, increased energy needs, and changing requirements in the nutrients critical for optimal growth and development. Infants and toddlers also experience physiological changes and have specific nutritional needs. Food and nutrition experts can provide women of childbearing age with adequate dietary advice to optimize nutrition, as well as guidance on selecting appropriate dietary supplements. Considering the approaching 2020-2025 Dietary Guidelines for Americans (DGA) will be making specific recommendations for children, it is important to provide accurate scientific information to support health influencers in the field of nutrition. The purpose of this review is to summarize the nutrition and supplementation literature for the first 1000 days; to highlight nutritional and knowledge gaps; and to educate nutrition influencers to provide thoughtful guidance to mothers and families. Optimal nutrition during pregnancy through early childhood is critical for supporting a healthy life. Nutrition influencers, such as dietitians, obstetricians/gynecologists, and other relevant health professionals, should continue guiding supplement and food intake and work closely with expectant families and nutrition gatekeepers.

Quantification of Lutein + Zeaxanthin Presence in Human Placenta and Correlations with Blood Levels and Maternal Dietary Intake

Lutein + zeaxanthin (L + Z) are carotenoids recognized in eye health, but less is known about their status during pregnancy. While quantified in maternal and umbilical cord blood, they have never been analyzed in placenta. The purpose of this study is to quantify combined L + Z concentrations in human placenta and correlate with levels in maternal dietary intake, maternal serum, and umbilical cord blood. The proportions of combined L + Z were compared within diet, placenta, maternal serum, and umbilical cord blood among additional carotenoids (lycopene, β-cryptoxanthin, α-carotene, and β-carotene). This Institutional Review Boardapproved cross-sectional study enrolled 82 mother-infant pairs. Placenta, maternal serum, and umbilical cord blood samples were analyzed for carotenoids concentrations. Mothers completed a food frequency questionnaire and demographic/birth outcome data were collected. L + Z were present in placenta, median 0.105 micrograms/gram (mcg/g) and were significantly correlated with maternal serum (r = 0.57; p < 0.001), umbilical cord blood levels (r = 0.49; p = 0.001), but not dietary intake (p = 0.110). L + Z were the most prevalent in placenta (49.1%) umbilical cord blood (37.0%), but not maternal serum (18.6%) or dietary intake (19.4%). Rate of transfer was 16.0%, the highest of all carotenoids. Conclusively, L + Z were identified as the two most prevalent in placenta. Results highlight unique roles L + Z may play during pregnancy.

Status of Retinoids and Carotenoids and Associations with Clinical Outcomes in Maternal-Infant Pairs in Nigeria

Vitamin A is an essential nutrient in pregnancy, and other carotenoids have been independently associated with maternal-infant outcomes. The objective of this study was to quantify the status of vitamin A and carotenoids in Nigerian maternal-infant pairs at delivery, compare these to a cohort from a developed nation, and determine the impact on clinical outcomes. Maternal and cord blood samples were collected in 99 Nigerian mother-infant pairs. Concentrations of lutein + zeaxanthin, β-cryptoxanthin, lycopene, α- and β-carotenes, and retinol were measured using HPLC. Descriptive statistics were calculated and Spearman coefficients were used to assess correlations between maternal and cord measurements; Mann-Whitney tests were used to compare median plasma values between dichotomous variables. Linear regression models were used to adjust for relevant confounders. A p < 0.05 was considered statistically significant. Thirty-five percent of mothers had plasma retinol concentrations ≤0.70 µmol/L; 82% of infants had plasma retinol concentrations ≤0.70 µmol/L at delivery. Maternal and infant concentrations of vitamin A compounds were highly correlated and were associated with newborn growth and Apgar scores. Despite plasma concentrations of pro-vitamin A carotenoids higher than those reported in other populations, pregnant Nigerian women have a high prevalence of vitamin A deficiency. As vitamin A related compounds are modifiable by diet, future research determining the clinical impact of these compounds is warranted.

Intrinsic and Extrinsic Factors Impacting Absorption, Metabolism, and Health Effects of Dietary Carotenoids

Carotenoids are orange, yellow, and red lipophilic pigments present in many fruit and vegetables, as well as other food groups. Some carotenoids contribute to vitamin A requirements. The consumption and blood concentrations of specific carotenoids have been associated with reduced risks of a number of chronic conditions. However, the interpretation of large, population-based observational and prospective clinical trials is often complicated by the many extrinsic and intrinsic factors that affect the physiologic response to carotenoids. Extrinsic factors affecting carotenoid bioavailability include food-based factors, such as co-consumed lipid, food processing, and molecular structure, as well as environmental factors, such as interactions with prescription drugs, smoking, or alcohol consumption. Intrinsic, physiologic factors associated with blood and tissue carotenoid concentrations include age, body composition, hormonal fluctuations, and variation in genes associated with carotenoid absorption and metabolism. To most effectively investigate carotenoid bioactivity and to utilize blood or tissue carotenoid concentrations as biomarkers of intake, investigators should either experimentally or statistically control for confounding variables affecting the bioavailability, tissue distribution, and metabolism of carotene and xanthophyll species. Although much remains to be investigated, recent advances have highlighted that lipid co-consumption, baseline vitamin A status, smoking, body mass and body fat distribution, and genetics are relevant covariates for interpreting blood serum or plasma carotenoid responses. These and other intrinsic and extrinsic factors are discussed, highlighting remaining gaps in knowledge and opportunities for future research. To provide context, we review the state of knowledge with regard to the prominent health effects of carotenoids.

Vitamin A nutritional status in high- and low-income postpartum women and its effect on colostrum and the requirements of the term newborn

OBJECTIVE

To evaluate the vitamin A status in serum and colostrum of postpartum women with different socioeconomic status, comparing the colostrum retinol supply with the vitamin A requirement of the newborn.

METHODS

Cross-sectional study conducted with 424 postpartum women. Vitamin A maternal dietary intake was estimated using a food frequency questionnaire. Colostrum and serum retinol levels were measured by high performance liquid chromatography (HPLC). Serum retinol concentrations <20μg/dL were indicative of vitamin A deficiency (VAD). Vitamin A levels provided by colostrum <400μgRAE/day were considered as insufficient for term newborns.

RESULTS

The mean maternal vitamin A intake during pregnancy was 872.2±639.2μgRAE/day in low-income women and 1169.2±695.2μgRAE/day for high-income women (p<0.005). The prevalence of vitamin A deficiency was 6.9% (n=18) in the low-income group and 3.7% (n=6) in the high-income group. The estimated mean retinol intake by infants of the high- and low-income mothers were 343.3μgRAE/day (85.8% AI) and 427.2μgRAE/day (106.8% AI), respectively.

CONCLUSIONS

Serum vitamin A deficiency was considered a mild public health problem in both populations; however, newborns of low-income women were more likely to receive lower retinol levels through colostrum when compared with newborns of high-income mothers.

Health Effects of Carotenoids during Pregnancy and Lactation

Adequate nutrition is particularly important during pregnancy since it is needed not only for maintaining the health of the mother, but also determines the course of pregnancy and its outcome, fetus development as well as the child’s health after birth and during the later period of life. Data coming from epidemiological and interventions studies support the observation that carotenoids intake provide positive health effects in adults and the elderly population. These health effects are the result of their antioxidant and anti-inflammatory properties. Recent studies have also demonstrated the significant role of carotenoids during pregnancy and infancy. Some studies indicate a correlation between carotenoid status and lower risk of pregnancy pathologies induced by intensified oxidative stress, but results of these investigations are equivocal. Carotenoids have been well studied in relation to their beneficial role in the prevention of preeclampsia. It is currently hypothesized that carotenoids can play an important role in the prevention of preterm birth and intrauterine growth restriction. Carotenoid status in the newborn depends on the nutritional status of the mother, but little is known about the transfer of carotenoids from the mother to the fetus. Carotenoids are among the few nutrients found in breast milk, in which the levels are determined by the mother’s diet. Nutritional status of the newborn directly depends on its diet. Both mix feeding and artificial feeding may cause depletion of carotenoids since infant formulas contain only trace amounts of these compounds. Carotenoids, particularly lutein and zeaxanthin play a significant role in the development of vision and nervous system (among others, they are important for the development of retina as well as energy metabolism and brain electrical activity). Furthermore, more scientific evidence is emerging on the role of carotenoids in the prevention of disorders affecting preterm infants, who are susceptible to oxidative stress, particularly retinopathy of prematurity.

The socioeconomic variables influence in the alpha-tocopherol concentration of the maternal serum

Abstract Objectives: To evaluate the influence of the socioeconomic factors on the alpha-tocopherol concentration in maternal serum. Methods: a retrospective, observational, cross-sectional study with the participation of 103 adult parturient volunteers attended at Hospital Universitário Ana Bezerra (Ana Bezerra University Hospital) in Santa Cruz - Rio Grande do Norte. 5.0 mL of blood was collected from each participant in fasting before the delivery to extract alpha-tocopherol of the serum. Socioeconomic and demographic information were obtained by a previously structured questionnaire. Alpha-tocopherol serum was determined by a High-Performance Chromatography Liquid (Cromatografia Líquida de Alta Eficiência (CLAE). Results: The average concentration of alpha-tocopherol in the serum was 1281.4 (594.8) µg/dL, and 6% of the women presented vitamin E deficiency (DVE). Most pregnant women aged between 18 and 24 years (59%), marital status was married or consensual marriage (77%), elementary schooling complete (34%), low family income (74%) and living in the urban area (73%). No significant differences were found in the alpha-tocopherol concentration according to socioeconomic characteristics and none of the studied factors were associated to the presence of DVE ( p >0.05). Conclusions: The maternal social characteristics were not determinants for the alpha-tocopherol serum and DVE. Further investigations should be carried out during lactation to assess which factors may be involved in the presence of this deficiency.

A Prospective Study of Serum Trace Elements in Healthy Korean Pregnant Women

This prospective study sought to investigate serum levels of trace elements (cobalt, copper, zinc, and selenium) and to assess their effects on pregnancy and neonatal outcomes. Serum levels of trace elements in 245 Korean pregnant women (median gestational age at delivery was 39 + 4 weeks and interquartile range was 38 + 4-40 + 1 weeks) were compared with those of 527 general adults and those of previous studies in other ethnic groups. Pregnancy and neonatal outcomes including gestational diabetes, preeclampsia, neonatal birth weight, and congenital abnormalities were assessed. The median serum trace element concentrations of all pregnant women were: cobalt: 0.39 μg/L (interquartile range, IQR 0.29-0.53), copper: 165.0 μg/dL (IQR 144.0-187.0), zinc: 57.0 μg/dL (IQR 50.0-64.0), and selenium: 94.0 μg/L (IQR 87.0-101.0). Serum cobalt and copper concentrations were higher in pregnant women than in the general population, whereas zinc and selenium levels were lower (p < 0.01). Concentrations of all four trace elements varied significantly during the three trimesters (p < 0.05), and seasonal variation was found in copper, zinc, and selenium, but was not observed for cobalt. The prevalence of preeclampsia was significantly lower with high copper (p = 0.03). Trace element levels varied by pregnancy trimester and season, and alteration in copper status during pregnancy might influence pregnancy outcomes such as preeclampsia.

Association between maternal vitamin E status and alpha-tocopherol levels in the newborn and colostrum

Vitamin E is important because of its antioxidant activity in situations of oxidative stress, especially postnatally. Hence, the objective was to verify whether maternal alpha-tocopherol level is associated with the alpha-tocopherol levels of the newborn and colostrum. This is a cross-sectional study of 58 women and their term newborns from a public hospital. Blood and colostrum were collected to measure alpha-tocopherol levels by high-performance liquid chromatography. Mothers with serum alpha-tocopherol levels <16.2 mmol L(-1) and newborns <11.6 mmol L(-1) were indicative of deficiency or low levels. Mothers were divided into two groups: <16.2 mmol L(-1) and those with levels ≥16.2 mmol L(-1) . The mean (95% confidence interval) serum alpha-tocopherol levels of mothers, umbilical cords and colostrum were 28 (24-32), 6 (5-8) and 39 mmol L(-1) (32-45), respectively (P < 0.001); 19% of the women and 90% of the newborns had low alpha-tocopherol levels. Maternal alpha-tocopherol level was associated with that of the umbilical cord. Newborns from mothers at risk of deficiency had low alpha-tocopherol levels (P < 0.001). Colostrum levels of vitamin E were not influenced by maternal serum. Maternal deficiency influenced the vitamin E level of the umbilical cord but does not in the colostrum, evidencing distinct transfer mechanisms via the mammary gland.

Vitamins A and E Deficiencies among Pregnant Women Attending Antenatal Care at General Hospital Dawakin Kudu, North-West Nigeria

Background:

Vitamins A and E deficiency is prevalent in developing countries, and plasma levels are low in pregnancy. This study was undertaken to determine the serum Vitamins A and E status among pregnant women attending antenatal care at a General Hospital in Dawakin Kudu, Kano and to provide the necessary information needed to suggest the supplementation of Vitamins A and E during pregnancy.

Methods:

The study was done in General Hospital Dawakin Kudu Local Government Area. Dawakin Kudu, a rural community in Kano State is about 12 km from Kano metropolis which is the most populous city in Nigeria and commercial nerve center of Northern Nigeria. Most of the women are housewives, however, some engage in subsistent farming and petty trading. This was a prospective study of 200 pregnant women at various maternal ages, gestational ages, and parities. Informed consent was obtained from the participants. Research structured questionnaire was administered to 200 respondents which showed age and parity distributions. Determination of Serum Vitamins A and E was done using methods of Bessey, et al. and Tsen. Ethical approval for the research was obtained from General Hospital, Dawakin Kudu, Kano. Statistical Analysis Used: Data obtained were analyzed using SPSS version 17 statistical software (SPSS Inc., IL, Chicago, USA). Descriptive statistics was done. Mean serum Vitamins A and E concentration between trimesters were compared using two-way ANOVA and P < 0.05 was considered statistically significant.

Results:

Majority of the women were aged 20–39 years with mean of 23.67 ± 6.11. Most were in the 1–4 parity range. Mean birth weight was 2.42 ± 0.74 kg. Above 65% were deficient while 34.5% had normal levels of Vitamin A and 51% were deficient of serum Vitamin E. Serum Vitamins A and E levels showed a marked reduction from first through third trimester. The differences were statistically significant (P < 0.05).

Conclusions:

There is a significant reduction in the serum Vitamins A and E concentration throughout the period of pregnancy with the highest levels in the first trimester. Therefore, further studies should evaluate the value of Vitamins A and E supplementation during pregnancy especially for those whose fruit and vegetable consumption is inadequate.

Physiology and its importance for reference intervals

Reference intervals are ideally defined on apparently healthy individuals and should be distinguished from clinical decision limits that are derived from known diseased patients. Knowledge of physiological changes is a prerequisite for understanding and developing reference intervals. Reference intervals may differ for various subpopulations because of differences in their physiology, most obviously between men and women, but also in childhood, pregnancy and the elderly. Changes in laboratory measurements may be due to various physiological factors starting at birth including weaning, the active toddler, immunological learning, puberty, pregnancy, menopause and ageing. The need to partition reference intervals is required when there are significant physiological changes that need to be recognised. It is important that laboratorians are aware of these changes otherwise reference intervals that attempt to cover a widened inter-individual variability may lose their usefulness. It is virtually impossible for any laboratory to directly develop reference intervals for each of the physiological changes that are currently known, however indirect techniques can be used to develop or validate reference intervals in some difficult situations such as those for children. Physiology describes our life's journey, and it is only when we are familiar with that journey that we can appreciate a pathological departure.