Folatos y vitamina B12 en la salud humana / Folate, vitamin B12 and human health

During the past decade the role of folate and vitamin B12 in human nutrition have been under constant re-examination. Basic knowledge on the metabolism and interactions between these essential nutrients has expanded and multiple complexities have been unraveled. These micronutrients have shared functions and intertwined metabolic pathways that define the size of the "methyl donor" pool utilized in multiple metabolic pathways; these include DNA methylation and synthesis of nucleic acids. In Chile, folate deficiency is virtually nonexistent, while vitamin B12 deficiency affects approximately 8.5-51% depending on the cut-off value used to define deficiency. Folate is found naturally mainly in vegetables or added as folic acid to staple foods. Vitamin B12 in its natural form is present only in foods of animal origin, which is why deficit is more common among strict vegetarians and populations with a low intake of animal foods. Poorfolate status in vulnerable women of childbearing age increases the risk of neural tube birth defects, so the critical time for the contribution of folic acid is several months before conception since neural tube closure occurs during the first weeks of life. The absorption of vitamin B12 from food is lower in older adults, who are considered to have higher risk of gastric mucosa atrophy, altered production of intrinsic factor and acid secretion. Deficiency of these vitamins is associated with hematological disorders. Vitamin B12 deficiency can also induce clinical and sub-clinical neurological and of other disorders. The purpose of this review is to provide an update on recent advances in the basic and applied knowledge of these vitamins relative to human health.

[Folate, vitamin B12 and human health]. / Folatos y vitamina B12 en la salud humana.

During the past decade the role of folate and vitamin B12 in human nutrition have been under constant re-examination. Basic knowledge on the metabolism and interactions between these essential nutrients has expanded and multiple complexities have been unraveled. These micronutrients have shared functions and intertwined metabolic pathways that define the size of the "methyl donor" pool utilized in multiple metabolic pathways; these include DNA methylation and synthesis of nucleic acids. In Chile, folate deficiency is virtually nonexistent, while vitamin B12 deficiency affects approximately 8.5-51% depending on the cut-off value used to define deficiency. Folate is found naturally mainly in vegetables or added as folic acid to staple foods. Vitamin B12 in its natural form is present only in foods of animal origin, which is why deficit is more common among strict vegetarians and populations with a low intake of animal foods. Poor folate status in vulnerable women of childbearing age increases the risk of neural tube birth defects, so the critical time for the contribution of folic acid is several months before conception since neural tube closure occurs during the first weeks of life. The absorption of vitamin B12 from food is lower in older adults, who are considered to have higher risk of gastric mucosa atrophy, altered production of intrinsic factor and acid secretion. Deficiency of these vitamins is associated with hematological disorders. Vitamin B12 deficiency can also induce clinical and sub-clinical neurological and of other disorders. The purpose of this review is to provide an update on recent advances in the basic and applied knowledge of these vitamins relative to human health.

Supplementation with engineered Lactococcus lactis improves the folate status in deficient rats.

OBJECTIVE: The aim of this study was to establish the bioavailability of different folates produced by engineered Lactococcus lactis strains using a rodent depletion-repletion bioassay. METHODS: Rats were fed a folate-deficient diet, which produces a reversible subclinical folate deficiency, supplemented with different L. lactis cultures that were added as the only source of folate. Three bacterial strains that overexpressed the folC, folKE, or folC +KE genes were used. These strains produce folates with different poly glutamyl tail lengths. The growth response of the rats and the concentration of folates in different organs and blood samples were monitored. RESULTS: The folate produced by the engineered strains was able to compensate the folate depletion in the diet and showed similar bioavailability compared with commercial folic acid that is normally used for food fortification. Folate concentrations in organ and blood samples increased significantly in animals that received the folate-producing strains compared with those that did not receive bacterial supplementation. Hematologic studies also showed that administration of the L. lactis strains was able to revert a partial megaloblastic anemia caused by folate deficiency. No significant differences were observed in the bioavailability of folates containing different glutamyl tail lengths. CONCLUSION: To our knowledge, this is the first study that demonstrated that folates produced by engineered lactic acid bacteria represent a bioavailable source of this essential vitamin.

Papel del ácido fólico en la etiología de las anemias megaloblásticas / Role of folic acid in the etiology of megaloblastic anemias

Se hace una revisión sobre el metabolismo de los folatos, su estructura química, fuentes dietéticas y requerimientos diarios en lso diferentes grupos de edades y estados patológicos, así como su absorción y distribución en el organismo. Se expone además la función matabólica del ácido fólico y su papel etiológico en el desarrollo de las anemias megaloblásticas, las causas de la deficiencia de este metabolilto y su tratamiento (AU)

Papel del ácido fólico en la etiología de las anemias megaloblásticas / Role of folic acid in the etiology of megaloblastic anemias

Se hace una revisión sobre el metabolismo de los folatos, su estructura química, fuentes dietéticas y requerimientos diarios en lso diferentes grupos de edades y estados patológicos, así como su absorción y distribución en el organismo. Se expone además la función matabólica del ácido fólico y su papel etiológico en el desarrollo de las anemias megaloblásticas, las causas de la deficiencia de este metabolilto y su tratamiento