Iron deficiency affects 2 billion people, about 1/3 of the total world-wide population. In addition, the World Health Organization (WHO) estimates that in the developing world, 43 percent of all non-pregnant women 15 to 59 years of age, and 56 percent of pregnant women, are iron deficient, as are close to 80 % of infants between 6 and 36 months of age.
|“Now there are over 90 papers showing weekly doses are effective in improving iron reserves and even correcting moderate anemia,” says Dr. Viteri.
“Iron is absolutely vital given its pivotal role in oxygen utilization,” says CHORI Scientist, Fernando Viteri, MD, ScD. “It affects all body functions.”
Iron deficiency has significant negative impact on all populations, but in pregnant women in particular, iron deficiency – especially during the 1st and 2nd trimester – can impact outcomes, causing premature delivery, low birth weight, and even death if anemia is severe. As a result, iron supplementation has long been recognized as a therapeutic tool for treating iron deficiency and anemia, especially in pregnant women.
For the last ten years however, Dr. Viteri has been leading a quiet revolution to shift from therapeutic daily supplementation, to preventative weekly supplementation.
“While 20 percent of women who have some iron reserves prior to pregnancy develop anemia during pregnancy,” says Dr. Viteri, “more than 80 percent of women who have little or no iron reserves before pregnancy develop anemia. That is why preventative treatment is so necessary.”
One could still treat iron preventatively with daily supplementation, however. The reason for the weekly dose – and in far smaller amounts – is biological, and corresponds with the turn-over of the intestinal lining, which renews itself every 5 to 6 days. “The fresh cells are programmed to absorb iron according to the person’s iron reserves: more if reserves are depleted, and less if they are adequate.”
premature delivery – due not to iron deficiency, but to iron excess and high hemoglobin levels, which epidemiologic studies have shown carry equal if not greater outcome risks.
|“Infants in France, school children in Guatemala and Colombia, adolescents in Malaysia, infants in China, Mexico, Venezuela - all these different populations show the same thing.” ||
The evidence in support of both preventative and weekly supplementation is so significant now that Nutrition Reviews has published in their December, 2005 issue a special supplement reporting on the results of Dr. Viteri’s last decade of research with his international colleagues.
Yet more compelling, however, are the results of Dr. Viteri’s latest study in collaboration with scientists at the National Institute of Perinatology in Mexico on hemoglobin concentrations and pregnancy outcomes in non-anemic women, to be published in the upcoming issue of Archives of Medical Research ( Casanueva E, Viteri FE, Mares-Galindo M, Meza-Camacho C, Loría A, Schnaas L, Valdés R. Weekly iron as a safe alternative to daily supplementation for nonanemic preganant women. Archives of Medical Research(2006) In Press).
They have shown for the first time that daily iron-folate supplementation at the iron doses recommended for pregnant women in iron-deficient populations by WHO and the Centers for Disease Control (CDC) is significantly correlated with a greater risk of low birth weight and
“What happened was that hemoglobin went up and up, so that by the end of the second trimester of pregnancy, 27 percent of the women on 60 mg of iron a day had hemoglobin levels that were undesirably high, increasing the risk of low birth weight and of premature delivery by 4 times in those women.” Only 7 percent of the women on weekly supplements developed high hemoglobin levels. This strongly suggests that the recommended daily iron doses are too high.
As Dr. Viteri points out, “More is not always better.”
While Dr. Viteri is still exploring the causal hypothesis for the prevalence of high hemoconcentrations, the new study confirms what Dr. Viteri has long been suggesting: that weekly iron-folate supplements, beginning prior to pregnancy and in much lower doses, supply the necessary iron to prevent iron deficiency without causing the iron excess associated with daily supplementation at currently recommended doses.
Monday, May 16, 2011 11:33 PM