|Vitamin C and oral iron|
|Vitamin C and oral iron||Tine Dusauchoit||15.04.97|
|Vitamin C and oral iron||Michael H.N. Golden||15.04.97|
|Vitamin C and oral iron||Benjamin Torun||15.04.97|
|Re: Vitamin C and oral iron||Michael H.N. Golden||15.04.97|
|Re: Vitamin C and oral iron||George Fuchs||16.04.97|
Tue, 15 Apr 1997 11:52:51 +0100 (BST)
From: Tine_DUSAUCHOITatbrussels.msf.org (Tine DUSAUCHOIT)
Subject: vitamin C and oral iron
hello to all,
I would like to have your opinion on the following problem. The question came from our team in burundi, where msf-b has several therapeutic and supplementary feeding centers.
As it is well known that vitamin c enhances the absorption of iron administered orally, would it be recommended to add vitamin c as a routine drug in the treatment of severly and moderatley malnourished children, as they suffer from anamia. i.e.: add extra vitamin c (tablets) on top of what the children already receive (eithertherapeutic milk, hem+cmv, fortified food) not in view of preventing/correcting deficiency of ascorbic acid but with the aim to have an increased absorption of oral iron.
If yes, what would be the recommended dose and when to administer (i.e. at seventh day as is the case for iron or before?
thank you for your suggestions
Subject: vitamin c and oral iron
Date: Tue, 15 Apr 1997 12:33:09 +0100 (BST)
From: "Michael H.N. Golden" <m.goldenatabdn.ac.uk>
This is an important point - do the diets we currently use have sufficient vitamin C to ensure adequate iron availability.
The whole idea of the F100 therapeutic milk and the mineral/vitamin mix that is added to the high-energy milk is that the nurses do not have to give extra vitamins and minerals - this makes the management much simpler.
The amount of vitamin C in the F100 is 10mg per 100 ml (100 kcal) so that a child of 5 kg who is gaining weight very rapidly during catch up and taking 200ml/kg will get about 100mg of vitamin C per day and even a child during the maintenance phase will be getting 50mg/d.
The recommended dietary requirement for this age is about 25mg/d - so that the actual intake will exceed the recommended amount for a normal child by quite a margin. We put this additional amount in because of the need for additional anti-oxidants in these children that are exposed to a hostile environment, because some evidence we have from the ratio of the different types of collagen fragments that are in their bones shows a longstanding vitamin C deficit in most children and also because we wanted to ensure adequate iron absorption during the catch up phase.
The recommended mineral/vitamin mix (CMV is supplied by Nutriset and complies to this specification) supplies the same amount of vitamin C when added to high-energy-milk as there is present in the F100 formula.
There is a theoretical risk of adding to much vitamin C in a child that has iron overload, as the children with kwashiorkor do have, in that iron plus vitamin C is used by the free-radical chemists as a model source of free-radicals, but there is no evidence that this is of any importance in the body, and at the moment I think we should ignore this possibility.
In terms of the other products, the GBG-porridge to the ACF recipe has 8mg vitamin C per 100 kcal, which should again be sufficient to ensure reduction of iron from the porridge. CSB, UNIMIX and SUPERUNIMIX also have substantial amounts of vitamin C added to them.
What is slightly more worrying is that we measured the phytic acid content of many of the porridges that are used in refugee feeding last year and they are universally high! This may mean that the iron (zinc, calcium and phosphorus) from the porridges that we use has a low availability becasue of this factor.
Prof. Michael H.N.Golden
Tue, 15 Apr 1997 16:31:42 +0100 (BST)
From: Benjamin Torun <btorunatnsem.incap.org.gt>
Subject: Vitamin C and oral iron
I want to follow-up on the original question raised by Tine Dusauchoit. It is important to bear in mind that the effect of vitamin C in enhancing iron absorption is an intraluminal phenomenon, due to the reduction of inorganic iron to the more absorbable ferrous state and/or formation of low molecular weight iron chelate that is soluble at the alkaline pH of the duodenum and "protects" the iron from the effect of phytates and other substances that produce non-soluble iron chelates.
Thus, vitamin C enhances iron absorption only if it is present in the stomach and intestine at the same time as the food source of inorganic iron. Therefore, there is no sense in "adding vitamin C as a routine drug in the treatment of severely and moderately malnourished children" for the purpose of improving iron nutriture, unless it is given at the same time as the iron source. In this regard, I do not see any advantage in providing it with a diet almost devoid of iron, as F100 (at least according to its composition in draft # 5.4, prepared 1.5 years ago, of the much awaited WHO Manual). This is not to say that vitamin C should not be given for other reasons.
In relation to the potential dangers or benefit of its use to enhance iron absorption in malnourished children, this effect has been more clearly demonstrated when the vitamin (or a food source that contains it) has been added to diets that contain inorganic iron --normally in amounts 10 or more times smaller than the therapeutic dose of 30 mg of iron usually given as supplement. It has been shown that addition of about 40 mg of vitamin C (about the same content as that in an orange) increases inorganic iron absorption from foods 2- or 3-fold. Its effect on therapeutic doses of iron is less clear, as the large amount of mineral tends to overwhelm the effect of ascorbic acid.
In conclusion, my suggestion would be to use vitamin C at a dose of 25-50 mg (which can be achieved with different foods) with each meal of inorganic iron-containing foods, especially when the diet is poor in hem iron and rich in phytates, or when supplementary iron is not given or there are doubts about the child's (or mother's) compliance in taking the supplement. I do not know of any studies on the effect of ascorbic acid on the absorption of therapeutic amounts of iron in malnourished children, but I do not think it would help much in view of the amount of mineral that will overload the intestinal capacity for absorption.
This can start immediately in moderately malnourished patients, but may be safer to wait 1-2 weeks after beginning dietary treatment for severe malnutrition.
Benjamin Torun, M.D., Ph.D.
Head, Human Nutrition Unit, Institute of Nutrition of Central America and Panama
INCAP -- Apartado Postal 1188, Guatemala, Guatemala
Tel:  472-3762, 471-5655, 471-9913, Fax:  473-6529
Subject: Re: Vitamin C and oral iron
Date: Tue, 15 Apr 1997 23:34:18 +0100 (BST)
From: "Michael H.N. Golden" <m.goldenatabdn.ac.uk>
Benny Torun raises a very important point about the content of iron in the milks that we use for rehabilitation.
The milks are deliberately very low in iron because of the dangers of iron during the citical period from admission until the children get back their appetites and start to grow (by which stage they have re-synthesised their transferrin and are infection free). They should then be given iron.
In ACF we find that the best way of giving iron to the children in this rapid growth phase is to add the iron to milk, destined for these children, at the point of preparation. This is quite simple: to give 2 mg per 100kcal (so that the rapidly growing child will get somewhere between 3 and 4 mg/kg/d) one 200 mg iron sulphate tablet is added for each 2 litres of milk.
The tablets are crushed, disolved and added to the milk in the kitchen for the high-energy-milk or at ward level for the pre-prepared sachets.
As Benny Torun points out, this way the vitamin C and the iron are presented together in the diet at the same time, which is a definite advantage. It also avoids the nurse/asistant having to go round each child giving a bolus dose of iron.
Prof. Michael H.N.Golden
Date: Wed, 16 Apr 1997 10:43:14 +0600
From: George Fuchs <gfuchsatcitechco.net>
Subject: Re: vitamin C and oral iron
For Tine Dusauchoit:
If you are providing bioavailable iron to malnourished children or adults who are iron deficient then the addition of vitamin C for this purpose alone is not necessary. Iron deficient individuals absorb iron very efficiently, particularly heme iron or one of the salts which are more bioavailable (eg. ferrous sulfate). Because of the large variety of potential dietary iron inhibitors (eg., Ca in milk) and enhancers, I would think that ensuring an adequate amount of supplemental dietary or medicinal iron is probably more important than adding vitamin C. As I suspect you already know, iron supplements should be withheld from severely malnourished children for the initial approximately two weeks because of the association with increased mortality/sepsis. All the best.
George Fuchs, MD
ICDDR,B - GPO 128
Mohakhali, Dhaka 1000, Bangladesh
Tel: 880 (2) 988-2399; Fax: 880 (2) 883-116, email: gfuchsatcitechco.net