Levels of Iron, Vitamin B&lt;sub&gt;12&lt;/sub&gt;, Folic Acid and Their Binding Proteins during Pregnancy

Zamorano, A. F.; Arnalich, Francisco; Casas, Emilio; Sicilia, Anita; Solis, Claudia; Vázquez, Juan José; Gasalla, R

doi:10.1159/000206175

Cited by 20 publications

(8 citation statements)

References 11 publications

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“…The falsely low B 12 may be the result of the low TCI levels found in 60% of this cohort. A similar finding is noted in normal pregnancy, with steadily decreasing B 12 levels throughout the three trimesters, correlating with a decrease in TCI levels over the same period [22]. As TCI is basically produced by granulocytes, it seems that OCs may exert some inhibitory effect on these cells, although 40% of the women had normal TCI levels and therefore, another metabolic pathway may be the cause for low vitamin B 12 .…”

Section: Discussionsupporting

confidence: 67%

Oral Contraceptives Can Cause Falsely Low Vitamin B<sub>12</sub> Levels

et al. 2000

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Serum vitamin B₁₂ radioimmunoassays may give falsely low results in patients with folate deficiency, multiple myeloma, megadose of vitamin C and following radioisotope organ scan. We evaluated 10 consecutive healthy women on oral contraceptives (OC) who had falsely low vitamin B₁₂ levels, as reflected by normal urine methylmalonic acid and plasma homocysteine. After 1-month cessation of OCs, vitamin B₁₂ returned to the normal range in all women. Transcobalamin I (TCI) blood level was decreased in 60% of patients. OCs may cause temporary low vitamin B₁₂ blood levels of no clinical significance that can be associated with low TCI levels

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Section: Discussionsupporting

confidence: 67%

Oral Contraceptives Can Cause Falsely Low Vitamin B<sub>12</sub> Levels

et al. 2000

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“…(Rothenberg et al, 1974;Sauberlich, 1975). However, as noted previously by Matte et al (1984) Wagner, 1985;Zamorano et al, 1985). In pigs, Mantzos et al (1974) noted the presence of a great quantity of unsaturated &dquo;avid specific binders&dquo; of folic acid in blood plasma of animals between 2 days and 3 years of age.…”

mentioning

confidence: 55%

Effects of intramuscular injections of folic acid on serum folates, haematological status and growth performance of growing-finishing pigs

Matte¹,

Girard²,

Bilodeau³

et al. 1990

Reprod. Nutr. Dévelop.

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Summary ― In a first trial, 48 piglets aged 5 weeks, grouped into 6 blocks of 8 pigs each, were used to determine the effect of intramuscular injections of folic acid on serum folates, haematological status, growth performance and carcass characteristics. Each block consisted of 2 pens of 4 pigs; in one pen, pigs received, by weekly intramuscular injections, an increasing volume of a solution containing 5 mg/ml folic acid, while in the other the animals were non-injected controls. The concentration of serum folates in treated pigs was 19% higher (P = 0.005) than in controls. There was no effect of treatment (P >_ 0.29) on haemoglobin and haematocrit. During the starting period, (5-11 weeks) average daily gain was not influenced by folic acid injections but feed intake and feed conversion were decreased (P = 0.07 and P = 0.05 respectively). No effect of folic acid (P >_ 0.23) was noted from 11-23 weeks of age, suggesting that the supplement was suboptimal during the growing-finishing period. In a second trial, 72 piglets aged 9 weeks were assigned to 6 blocks of 12 2 animals each. The following treatments were randomly distributed in each block according to a 2 x 3 factorial design: level of feeding (restricted vs ad libitum) and weekly intramuscular injections of increasing volume of solutions containing either 0, 15 or 30 mg/ml of folic acid. The variables studied were the same as in Trial 1. Concentrations of serum folates varied quadratically (P= 0.0001) with the dose injected, a plateau being attained with injections of 15 mg/ml. There was no effect of treatment (P = 0.043) on haemoglobin and haematocrit. During the growing period (9-15 weeks), no effect (P 0.72) of folic acid was noted on growth performance. However, during the finishing period (15-21 weeks), folic acid given at a dose of 30 mg/ml decreased (P = 0.006) feed intake while no effect (P 0.13) of the vitamin supplementation was noted on average daily gain and feed conversion. In both trials, there was no effect (P 0.21)

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“…However, when data are analyzed by trimester of pregnancy, it can be observed that during the first trimester there is a 44.79% deficiency, which is not explainable by a dilution effect, but also is too high to be only due to a nutritional deficiency. Trying to explain the high prevalence of vitamin B 12 deficiency during pregnancy besides the dilution effect, some authors have proposed changes in nutrient transference to the fetus, increased requirement and impaired absorption, especially in underdeveloped countries (Zamorano et al, 1985;Knight et al, 1994;Allen et al, 1995;Mc Grath et al, 1995;O'Connor 1995;Casterline et al, 1997).…”

Section: Discussionmentioning

confidence: 99%

High prevalence of folic acid and vitamin B12 deficiencies in infants, children, adolescents and pregnant women in Venezuela

et al. 2005

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Background: There is increased worldwide concern about the consequences of folic acid and vitamin B 12 deficiencies on health, which include megaloblastic anemia, neural tube defects and cardiovascular disease. Objective: This study intended to determine the prevalence of folic acid and vitamin B 12 deficiencies in vulnerable groups in labor and poor socioeconomic strata of the Venezuelan population. Methods: A total of 5658 serum samples were processed to determine folic acid and vitamin B 12 concentrations. The study involved three surveys performed during 2001-2002 and included infants, children, adolescents and pregnant women from labor and poor socioeconomic strata of the population. The method used was a radio immunoassay designed for the simultaneous measurement of serum folic acid and vitamin B 12 .Results: The prevalence of folic acid deficiency was higher than 30% for all groups studied, reaching 81.79% in adolescents. Vitamin B 12 deficiency was 11.4% in samples collected nationwide, but there was also a similar prevalence of high serum levels. The prevalence of folic acid and vitamin B 12 deficiencies in pregnant women reached 36.32 and 61.34%, respectively. Conclusion: This work shows that there is a high prevalence of folic acid deficiency, especially in women of reproductive age, pregnant adolescents and in the whole population studied in Vargas state. This situation requires immediate intervention as supplementation or food fortification programs.

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Levels of Iron, Vitamin B<sub>12</sub>, Folic Acid and Their Binding Proteins during Pregnancy

Cited by 20 publications

References 11 publications

Oral Contraceptives Can Cause Falsely Low Vitamin B<sub>12</sub> Levels

Oral Contraceptives Can Cause Falsely Low Vitamin B<sub>12</sub> Levels

Effects of intramuscular injections of folic acid on serum folates, haematological status and growth performance of growing-finishing pigs

High prevalence of folic acid and vitamin B12 deficiencies in infants, children, adolescents and pregnant women in Venezuela

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