Comparison of the nutritional status of pregnant adolescents with adult pregnant women. I. Biochemical findings

Morse, Ellen H.; Clarke, Robert P.; Keyser, Donald E.; Merrow, Susan B.; Bee, David E.

doi:10.1093/ajcn/28.9.1000

Cited by 21 publications

(12 citation statements)

References 8 publications

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“…Mean serum retinol concentrations of about 1.05¼mol/l (300¼g/l) have been reported during pregnancy among diverse groups of south Asian women1 – 6 in comparison with values of 1.57-1.75 ¼mol/l (450-500¼g/l) in better nourished populations 7…”

Section: Introductionmentioning

confidence: 99%

Double blind, cluster randomised trial of low dose supplementation with vitamin A or beta carotene on mortality related to pregnancy in Nepal

West¹,

Katz

Khatry³

et al. 1999

BMJ

426

296

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Objective To assess the impact on mortality related to pregnancy of supplementing women of reproductive age each week with a recommended dietary allowance of vitamin A, either preformed or as carotene. Design Double blind, cluster randomised, placebo controlled field trial. Setting Rural southeast central plains of Nepal (Sarlahi district). Subjects 44 646 married women, of whom 20 119 became pregnant 22 189 times. Intervention 270 wards randomised to 3 groups of 90 each for women to receive weekly a single oral supplement of placebo, vitamin A (7000 g retinol equivalents) or carotene (42 mg, or 7000 g retinol equivalents) for over 3 1 ⁄2 years. Main outcome measures All cause mortality in women during pregnancy up to 12 weeks post partum (pregnancy related mortality) and mortality during pregnancy to 6 weeks postpartum, excluding deaths apparently related to injury (maternal mortality). Results Mortality related to pregnancy in the placebo, vitamin A, and carotene groups was 704, 426, and 361 deaths per 100 000 pregnancies, yielding relative risks (95% confidence intervals) of 0.60 (0.37 to 0.97) and 0.51 (0.30 to 0.86). This represented reductions of 40% (P < 0.04) and 49% (P < 0.01) among those who received vitamin A and carotene. Combined, vitamin A or carotene lowered mortality by 44% (0.56 (0.37 to 0.84), P < 0.005) and reduced the maternal mortality ratio from 645 to 385 deaths per 100 000 live births, or by 40% (P < 0.02). Differences in cause of death could not be reliably distinguished between supplemented and placebo groups. Conclusion Supplementation of women with either vitamin A or carotene at recommended dietary amounts during childbearing years can lower mortality related to pregnancy in rural, undernourished populations of south Asia.

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Section: Introductionmentioning

confidence: 99%

Double blind, cluster randomised trial of low dose supplementation with vitamin A or beta carotene on mortality related to pregnancy in Nepal

West¹,

Katz

Khatry³

et al. 1999

BMJ

426

296

View full text Add to dashboard Cite

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“…The biomarker is also affected by smoking, pregnancy, age, gender and presence of infections, with usually lower plasma ascorbate levels in smokers [20][21][22] , men, pregnant women [23,24] , elderly people (e.g. due to reduced intake, chronic disease; there is no effect of aging itself [25] ) and people with infections [19,26,27] .…”

Section: Criteria For the Assessment Of Vitamin C Supplymentioning

confidence: 99%

“…In pregnant women, haemodilution (higher percentage increase of plasma volume than of erythrocyte volume) [23] and transfer of vitamin C to the foetus [58] lead to a decreased plasma ascorbate concentration and a higher requirement for vitamin C. However, convincing data on the quantitative determination of the requirement in pregnant women or the amount transferred to the foetus are not available.…”

Section: Pregnancymentioning

confidence: 99%

New Reference Values for Vitamin C Intake

Society¹

2015

Ann Nutr Metab

101

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The German, Austrian, and Swiss nutrition societies are the editors of the ‘reference values for nutrient intake'. They have revised the reference values for the intake of vitamin C and published them in February 2015. The average vitamin C requirement in healthy adults is considered to be the vitamin C amount that compensates for the metabolic losses of vitamin C, and ensures a fasting ascorbate plasma level of 50 µmol/l. Based on the present data from studies with non-smoking men, metabolic losses of 50 mg/day are assumed, as well as an absorption rate of 80% and an urinary excretion of 25% of the vitamin C intake. Taking this into account, the calculated average requirement in men is 91 mg/day. Considering a coefficient of variation of 10%, a reference value (recommended intake) of 110 mg/day for men is derived. The vitamin C requirement in women as well as in children and adolescents is extrapolated from the requirement in men and in relation to their body weight. This results in a recommended intake of about 95 mg/day for adult women. Because the requirement in pregnant and lactating women is increased, higher recommended intakes are derived for them, 105 mg/day for pregnant women from the fourth month on and 125 mg/day for lactating women, respectively. For boys and girls at the age of 1 to under 15 years, there are increasing recommended intake values from 20 to 85 mg/day. For male and female adolescents, at the age of 15 to under 19 years, the recommended intake is 105 and 90 mg, respectively. As smokers have higher metabolic losses and lower plasma levels of vitamin C than non-smokers (turnover is 40% higher), the reference value for vitamin C intake is set to 135 mg/day for female smokers and 155 mg/day for male smokers. For infants in their first year of life, the reference value (estimated value) is set to 20 mg vitamin C/ day, based upon the lowest observed vitamin C intake for infants in the United Kingdom and the United States, that obviously meets the requirement in infants and that is 3 times higher than the amount necessary to prevent scurvy (7 mg/day).

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“…For pregnant women, Afssa (2001) added 10 mg/day to the PRI for non-pregnant women (hence a PRI of 120 mg/day) to take into account haemodilution and the active transport of vitamin C through the cord and placenta (Morse et al, 1975). For lactating women, Afssa (2001) recommended an additional intake of 20-30 mg/day taking into account a vitamin C concentration in human milk of 40-60 mg/L (Salmenpera, 1984), and hence a PRI of 130 mg/day.…”

Section: Pregnancy and Lactationmentioning

confidence: 99%

“…For lactating women, Afssa (2001) recommended an additional intake of 20-30 mg/day taking into account a vitamin C concentration in human milk of 40-60 mg/L (Salmenpera, 1984), and hence a PRI of 130 mg/day. (2000) noted that the maternal plasma ascorbate concentration decreases during pregnancy because of haemodilution and active transfer to the fetus (Morse et al, 1975;Choi and Rose, 1989), but that the amount of vitamin C required for transfer to the fetus was unknown and was estimated taking into account that intakes of 7 mg/day prevent scurvy in young infants (Van Eekelen, 1953;Goldsmith, 1961;Rajalakshmi et al, 1965). The EAR for near-maximal neutrophil concentration in non-pregnant women was therefore increased by 10 mg/day and, after adding twice an assumed CV of 10 % (because the SD of the requirement for vitamin C was unknown) and rounding, RDAs for pregnancy of 80 mg/day (14-18 years) and of 85 mg/day (adult women) were derived.…”

Section: Pregnancy and Lactationmentioning

confidence: 99%

Scientific Opinion on Dietary Reference Values for vitamin C

Products¹

2013

EFS2

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Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies (NDA) derived Dietary Reference Values (DRVs) for vitamin C. The Panel concludes that an Average Requirement (AR) can be derived from indicators of vitamin C status, as well as a Population Reference Intake (PRI) assuming a coefficient of variation (CV) of 10 %. Several health outcomes possibly associated with vitamin C intake were also considered but data were found to be insufficient to establish DRVs. For healthy adults, the AR is determined from the quantity of vitamin C that balances metabolic vitamin C losses and allows the maintenance of an adequate body pool characterised by fasting plasma ascorbate concentrations at around 50 µmol/L. In men, an AR of 90 mg/day of vitamin C and a PRI of 110 mg/day are proposed. As no value for metabolic losses is available in women, the AR for women is extrapolated from the AR for men on the basis of differences in reference body weight, and an AR of 80 mg/day and a PRI of 95 mg/day are proposed. For infants aged 7-11 months, the Panel has decided to retain the PRI of 20 mg/day set by the SCF (1993), as no suitable evidence has emerged since the previous assessment. For children and adolescents, the ARs for vitamin C are extrapolated from the ARs for adults taking into account differences in reference body weight, and PRIs are derived, ranging from 20 mg/day for 1 to 3 year-old children, to 100 and 90 mg/day for boys and girls aged 15-17 years, respectively. For pregnant and lactating women, vitamin C intakes of 10 mg/day and of 60 mg/day in addition to the PRI of non-pregnant non-lactating women are proposed. Vitamin C (L-ascorbic acid) is an enzyme cofactor for biochemical reactions catalysed by monooxygenases, dioxygenases and mixed function oxygenases. Vitamin C plays an important role in the biosynthesis of collagen, is essential for the synthesis of carnitine and catecholamines, and is also involved in the metabolism of cholesterol to bile acids. Vitamin C in aqueous solution readily scavenges reactive oxygen and nitrogen species, and is part of the antioxidant network of the body. © EuropeanGastrointestinal absorption is about 80 % for an intake of about 100 mg/day. Vitamin C is transported as the free anion ascorbate in plasma, and is distributed to all tissues. Biomarkers of body stores are related to the size and turnover of vitamin C body stores, and to the mass balance of vitamin C in the body. In this Opinion, plasma ascorbate concentration is considered as the primary indicator of body stores. The mass balance of vitamin C in the body is determined from the rate of turnover of the body pool, considering metabolic losses, urinary losses and the quantity of vitamin C required for the replacement of these losses, taking into account absorption efficiency.Scurvy, characterised by symptoms related to connective tissue defects, occurs in adults at a plasma ascorbate concentration below 10 µmol/L and a body pool less than 300 mg, and can be prevented w...

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Comparison of the nutritional status of pregnant adolescents with adult pregnant women. I. Biochemical findings

Cited by 21 publications

References 8 publications

Double blind, cluster randomised trial of low dose supplementation with vitamin A or beta carotene on mortality related to pregnancy in Nepal

Double blind, cluster randomised trial of low dose supplementation with vitamin A or beta carotene on mortality related to pregnancy in Nepal

New Reference Values for Vitamin C Intake

Scientific Opinion on Dietary Reference Values for vitamin C

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