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Greetings, all. I'm not sure I can find the answers I'm looking for here, but I thought it would be a good place to start.<br><br><br><br>
Recently I've been assessing how I'm doing regarding my iron intake. I've learned a few "facts" from the internet, to start.<br><br><br><br>
1. There are two kinds of iron, heme and nonheme. Nonheme is the type we get from vegetables, beans, and other non-animal products.<br><br><br><br>
2. Nonheme iron isn't as easily absorbed as heme iron. Anywhere from 2-20% is what we absorb.<br><br><br><br>
3. Vitamin C helps the body absorb nonheme iron.<br><br><br><br>
4. Someone like me (female, 29, never been pregnant) needs about 15 milligrams of iron per day.<br><br><br><br>
So those are the assumptions I'm working off.<br><br><br><br>
Now, on my food's nutrition labels, it only lists iron as a percentage of the RDA. Here's my breakfast for this morning:<br><br><br><br>
1 1/2 cups Cheerios, 1 cup fortified soymillk, 1/4 cup raspberries.<br><br>
Total iron (according to labels): 30% + 6% + 6% = 42% RDA<br><br>
Total vitamin C (according to labels): 0% + 4% + 15% = 19%<br><br><br><br>
So here are my questions:<br><br><br><br>
1. What is the percentage RDA on the label based on. Adult male? Did I really consume 42% of my RDA for iron?<br><br><br><br>
2. Do the percentages take into account the low absorption rate of nonheme iron? That is, could the meal have contained 30 milligrams of iron, but the label-makers know only about 6 milligrams would be aborbed, so the mark it as 30% RDA? Or do I have to eat 500% my RDA because only 1/5 of the iron is readily absorbed?<br><br><br><br>
3. How much vitamin C does it take to speed aborption? Is there a formula or ratio somewhere? With 19% vitamin C in the same meal, did I get more like 52% of my RDA or 75% or...?<br><br><br><br>
Those are all the questions I have for now. I realize they're kind of complicated, but if someone could even point me in the right direction for further study, that would be great. Thanks!
 

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Hi Medesha ,<br><br>
Statements 1 to 4 are more or less correct .<br><br><br><br>
I am trying to work out your reasoning for the interest you have shown in your research , maybe you want to be a naturopath or some thing or it might be just personal knowledge .<br><br><br><br>
Any way its probably best to get a blood test and work backwards .<br><br><br><br>
There are so many factors that affect the statements you mentioned Absorption of vit C , RDA , milligrams , age , sex etc .<br><br><br><br>
If your emotions , diet , environment to name a few are reassembly balanced , you wont have to worry about iron levels<br><br><br><br>
Wish you well
 

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<div class="quote-container"><span>Quote:</span>
<div class="quote-block">Originally Posted by <strong>Medesha</strong> <a href="/forum/post/0"><img alt="View Post" class="inlineimg" src="/img/forum/go_quote.gif" style=""></a><br><br><br>
1 and 2</div>
</div>
<br>
Normally for US RDA's absorption is taken into account but I'm not sure if gender is...the differences are relatively small so I don't think it makes a difference but don't take my word on it. I could be wrong.<br><br><br><br><div class="quote-container"><span>Quote:</span>
<div class="quote-block">3. How much vitamin C does it take to speed aborption? Is there a formula or ratio somewhere? With 19% vitamin C in the same meal, did I get more like 52% of my RDA or 75% or...?</div>
</div>
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I do have ratios on my computer that has recently bit the dust. Off the cuff I want to say that it's a 1:1 or 1:2 ratio. Vitamin C can donate an electron (or two) for every ferric iron (Fe3 [non-heme]) to turn it into a ferrous iron (Fe2 [heme]). Rates of iron release from storage and conversion from ferric to ferrous will/can vary depending where the C is and where the iron is. Again, don't quote me on this but from what i understand iron release and conversion ocurrs more rapidly at lower ph's (i.e., lisosome inside a cell- ph 4) and more slowly at higher ph's (i.e., blood ph=7). I imagine low stomach ph plays a role here. I'm pretty sure the release from storage is around 60%. I think a couple of ounces of OJ would do the trick with any meal or some other C source. C is so easy to get and usually foods that have it have a lot of it so I don't think you should worry about the ratios.
 

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Just one other thought<br><br><br><br>
you might / might not like to pm Lothar M Kirsch to read your post and see if he can add any thing .
 

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No need for PM, I just happened to see the thread.<br><br><br><br>
RDA have been established nearly 40 years ago and are now RDIs. They differ from country to country. The precentage is given for 2000 kCal, not looking if that covers your specific needs. It doesn't calculate the absorption rate, as this would be impossible (someone drinks OJ and iron absorption goes up, and someone drinks black tea and the absorption rate drops). I can't answer your 3rd question. But I'd follow a more practical way: try to find out if you need more iron (which is what I expect) or if you already have enough. If you need to build up your iron storage use iron cookware (simmered tomatoes would be rich in iron), or full rye bread, or any of the foods you like that are iron-rich, and eat vitamin C rich foods at the same time.<br><br>
And: I don't eat lots of foods with RDIs on the label as they also tend to be rich in artificial flavours and colours.
 

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It is true that of the two types, heme iron is more absorbable, however, vegans and vegetarians are no more likely to get anemia than nonvegetarians. (ADA position paper on Vegetarianism)<br><br><br><br>
a very authoritative source on this is: veganhealth.org ,<br><br>
that cites every study it uses to come up with a summary of recommendations for those who abstain from cruelty-produced foods. However, this source, as others do, tends to look at nutrition as a combination of <span style="text-decoration:underline;">individual</span> minerals/vitamins/nutrients, and overlooks the fact that whole plant foods are much more than a couple of minerals and nutrients all in one place, but rather a dynamic synergy of nutrients evolved over billions of years, each part integral to and indistinguishable from the whole. A great medical source for this approach is the Physicians' Committee for Responsible Medicine, with many articles and studies on plant-based nutrition - pcrm.org - Thus, I suggest you focus on <span style="text-decoration:underline;">whole</span> plant foods as much as possible for your iron increase, and in optimizing the other aspects of your nutrition.<br><br><br><br><br><br>
To answer your question, Iron amounts listed on a nutrition label are based on 18 mg/day = 100% RDI. The article on : <a href="http://www.veganhealth.org/articles/iron" target="_blank">http://www.veganhealth.org/articles/iron</a> shows that the new RDI for iron for vegetarian women above 19 is 32.4mg - <span style="text-decoration:underline;">however</span>, the article points out that this was not figured out by studying vegetarians!! The USDA chose this suggeted intake by <span style="text-decoration:underline;">multiplying the nonvegetarians' RDI by 1.8</span>! This is very unscientific, and not representative of the population, because there was no study of vegetarians to conclude this. That's why many dietitians say it's not necessay to get this much iron. I personally say, listen to your body first. Try consuming ~18mg a day of nonheme iron by eating whole plant foods, and vitamin C foods, for two weeks. Then notice how you feel - body temperature, energy level, .... And evaluate if that is sufficient, otherwise try more vit-C containing foods, or increase the iron foods, - but make sure to stop drinking coffee and green/black tea also (which inhibit iron absorption).<br><br><br><br><br><br>
You can get that roughly 18mg of iron a day by eating a cup of pumpkin seeds (1C=16T), which would give you about 20mg, and then a cup or so of a fruit. But where I live pumpkin seeds are $4.00/lb, so you could also do this:<br><br><br><br><br><br>
Eat a few cups throughout the day of whole grains (whole wheat pasta, any bean, any nut, oatmeal, wholegrain bread, brown rice, ricecakes, etc.) right along with some nice vitamin-C-rich whole foods, - i.e. citrus fruits, strawberries, green leafy vegetables (broccoli, kale, collards, swiss chard, brussel sprouts), bell peppers (yellow, red, and green), and cauliflower.<br><br><br><br>
And for overall health, make sure to get plenty of dark green leady vegetables, yellow vegetables, other vegetables (frozen or raw), fruits, nuts, legumes, and whole grains. And, - one tablespoon of flaxseeds - (you can grind in a blender, uncooked, kept refrigerated for a few weeks) daily.<br><br>
And every few days or so, a 1"x5" strip of kombu seaweed (iodine for thyroid) (can soak for 5 min, then eat).<br><br><br><br><br><br>
Flaxseeds are $2.00/lb where I live at wild oats.<br><br>
Kombu seaweed is $2.00 a package (~16 servings) at an asian supermarket in my town.<br><br><br><br><br><br><br><br><br><br>
here's a table from the iron article on veganhealth.org<br><br><br><br>
Iron Content of Common Foods<br><br>
\tServing \tmg<br><br>
fortified cereals \t1/2 C \tvaries<br><br>
soybeansA \t1/2 C \t4.4<br><br>
blackstrap molasses \t1 T \t3.3<br><br>
pumpkin seeds \t2 T \t2.5<br><br>
chickpeasA \t1/2 C \t2.4<br><br>
pinto beansA \t1/2 C \t2.2<br><br>
apricots, dried \t1/4 C \t1.5<br><br>
spinachA \t1/2 C \t1.5<br><br>
oatmealA \t3/4 C \t1.2<br><br>
raisins \t1/4 C \t1.1<br><br><br><br><br><br><br><br>
The suggested links are:<br><br><br><br>
veganhealth.org<br><br>
pcrm.org<br><br><br><br><br><br><br><br>
"Love animals, don't kill them!"
 

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<div class="quote-container"><span>Quote:</span>
<div class="quote-block">Originally Posted by <strong>Lothar M Kirsch</strong> <a href="/forum/post/0"><img alt="View Post" class="inlineimg" src="/img/forum/go_quote.gif" style=""></a><br><br>
No need for PM, I just happened to see the thread.<br><br><br><br>
RDA have been established nearly 40 years ago and are now RDIs. They differ from country to country. The precentage is given for 2000 kCal, not looking if that covers your specific needs. It doesn't calculate the absorption rate, as this would be impossible (someone drinks OJ and iron absorption goes up, and someone drinks black tea and the absorption rate drops). I can't answer your 3rd question. But I'd follow a more practical way: try to find out if you need more iron (which is what I expect) or if you already have enough. If you need to build up your iron storage use iron cookware (simmered tomatoes would be rich in iron), or full rye bread, or any of the foods you like that are iron-rich, and eat vitamin C rich foods at the same time.<br><br>
And: I don't eat lots of foods with RDIs on the label as they also tend to be rich in artificial flavours and colours.</div>
</div>
<br><br><br>
I don't know lothar. Granted, everything can't be accounted for but bioavailability is addressed in the US RDA/RDI's/whatever for many of our nutrients. This I'm learning especially with calcium.
 

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Maybe they put into account what's in the product they measure (e.g. iron/vit C/oxalate ...), but what about what you eat/drink at the same time?
 

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Discussion Starter · #9 ·
Wow, thanks for all the great information! I'm not feeling poorly or anything, just curious about what I eat. And I am thinking about going back to uni and studying nutritional science, maybe possibly one day. Thanks again!
 

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I just wanted to add that I have always wondered these kinds of questions too. With a search on PubMed, this is what came up that should answer part of this question:<br><br><br><br><a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=abstractplus&db=pubmed&cmd=Retrieve&dopt=abstractplus&list_uids=15743017" target="_blank">http://www.ncbi.nlm.nih.gov/entrez/q..._uids=15743017</a><br><br><br><br>
"Meals containing low to medium levels of inhibitors require the addition of AA [Ascorbic Acid = Vitamin C] at a molar ratio of 2:1 (e.g., 20 mg AA: 3 mg iron). To promote absorption in the presence of high levels of inhibitors, AA needs to be added at a molar ratio in excess of 4:1, which may be impractical."<br><br><br><br>
With inhibitors I think they mean oxalates and things like that. My nutrition knowledge is getting rusty.
 

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That's very interesting.<br><br>
Most probably oxalates and phytates. I'm far from sure, but my guess is that the inhibitors compete with the iron for the AA.
 
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