Iron Warning for Sugar Gliders

This is for diet-watchers only. If you hate diet discussions, just ignore this.

OK, please ask yourself this question as you read this:

"Does it make sense to give a sugar glider the same dose of daily Iron as what is recommended for a human being?"

There is mounting evidence that it is easy to overdose your gliders on iron. Too much iron can hurt their kidneys and liver, and it can dull their fur. We at LGRS have anecdotal evidence this is true based on observations of many incoming rescues and there has been some scholarly research and even necropsies done on gliders that suggest caution in the amounts of iron you feed.

For example a study published in 2009 states: "Iron is a common contaminant of calcium supplements and can lead to oxidative damage and iron storage disease at high levels." (see footnote 1)

In this study, the researchers cite three diets formulated for sugar gliders using 87-mg/kg, 175-mg/kg, and 292-mg/kg iron respectively, all of which are characterized as (appearing) "to supply more iron [and vitamin C] than sugar gliders need."

Another sugar glider research report (some have discredited this research as being incomplete) goes on to say this about iron:

"Iron Storage disease has been described in captive frugivorous birds, bats, and primates, often as a secondary finding at necropsy. Although it has not previously been reported in sugar gliders, evidence of excess tissue iron has been seen in sugar gliders at necropsy (Thomas, unpublished personal communication, 2003; necropsies performed at Great Neck Veterinary Clinic, Virginia, VA USA, and biopsy tissue submitted in formalin reported by Tammy Johnson, DVM, ACVP). Dietary excesses of iron (both from supplements as well as from animal-based foods [heme versus nonheme iron]) can contribute to this syndrome, along with high levels of dietary vitamin C, which directly increase iron absorption. In this trial, we also recorded elevated iron in the feces of all sugar gliders (data not reported here), and so we suspect dietary iron overload." (see footnote 2)

Now let's put this into context by comparing these amounts to what is recommended for human beings. According to a well-known vitamin expert, Dr. George Obikoya, it is easy for humans to overdose on iron…

"So how much iron do you really need? Iron is not excreted. The iron you absorb stays and accumulates in storage except that you can lose one milligram a day through hair, finger nails, skin cells and other detritus. That is the amount needed every day to replace the loss. One milligram, that’s all and for women in reproductive years, one and a half milligram. The other way to lose iron, of course, is by blood loss." (see footnote 3)

Did you get that folks? HUMAN BEINGS need one milligram per day to keep iron levels where they need to be? Then why would a sugar glider, that weighs about a quarter of a pound, need just shy of a milligram each day? It is well known that an overdose of iron in humans means a toxic buildup in organs such as the liver and in rare instances the heart. So why does it make sense that a sugar glider should ingest close to a milligram a day of iron? Well of course it does not make sense which is why the glider communities' love affair with certain diets is just plain weird.

We also know that raisins and grapes are high in iron and the ASPCA and thousands of vets have sworn off raisins and grapes for dogs (footnote 4). Although there is still more study to be done on the source of the toxicity in grapes and raisins, some vets think iron is a stand-out suspect. Hey, I'm not gambling with my dogs' lives or my gliders so no grapes or raisins for either of those species in my house.

Now let's get down to some comparative facts:

When you add the iron content of iron-fortified baby foods, herptivite, wheat germ and other iron-rich items, it is easy to end up feeding a glider almost a full mg of iron at each meal.

If you go to the sugarglider.com resources/nutrition section you will see recipes for popular diets.

mg/kg or ppm is easy to figure by just eyeballing the total weight of the batch of the recipe and comparing that to the absolute amount of iron.

Some examples based on nutritional analysis based on the recipes entered in the sugarglider.com nutrition database:

BML yields 57 ppm of iron
(based on recipe #10 here, recipe #1 shows even more because some of the baby foods are different)
Taronga Zoo Diet yields 32 ppm of iron
LGRS suggie soup yields 9 ppm of iron
Eric's Example Recipe yields 1.69 ppm of iron

Here are some individual ingredients of some diets you can consider:

Herptivite 3,850 ppm of iron
(yes that's three thousand, eight hundred and fifty see Pro Geckos Website for analysis)
Vionate has 550 ppm of iron
Trader Darwin's Vanilla Flavored Soy 343 ppm of iron
HPW Powder has 8 ppm of iron

(Keep in mind that dark, green leafy vegetables like spinach are high in Oxalates and Oxalic acid does interfere with the uptake of iron. It is well known that oxalates interfere with the metabolism of calcium also).

So you've been warned. Take a look at the nutritional analysis of what you are feeding your gliders. Take the time. If you are feeding a tablespoon of any diet and its Iron ppm is in the range of 55 to 65, you are feeding approximately one mg of iron which is the maintenance dose for a human being. Think about it. You can drastically reduce the iron by cutting back on wheat germ, herptivite, and iron-enriched baby foods.

Show your vet the nutritional analysis of diets. Then ask for an opinion. Don't go by "internet popularity." Actually show the analysis to your vet and ask the question: "Does it make sense to give a sugar glider the same dose of daily Iron as what is recommended for a human being?"


Footnotes:

(1) Dierenfeld, ES, "Feeding Behavior and Nutrition of the Sugar Glider (Petaurus breviceps)" Sustainable Program Research, Novus International Inc., 20 Research Drive, St. Charles, MO and Elsevier, Inc. 2009.

(2) Dierenfeld ES, Thomas D, Ives R. "Comparison of commonly used diets on intake, digestion, growth, and health in captive sugar gliders (Petaurus breviceps)" Journal of Exotic Mammal Medicine and Surgery Vol 15, Issue 3, pp 218–24, July 2006.

(3) Obikoya, G. "Too Much Iron: Iron Overdose," referencing NEJM Feb 1999 340:409-17; and American Journal of Clinical Nutrition 73: 503, 638, 2001. www.vitamins-nutrition.org/vitamins/iron-overdose.html

(4) ASPCA Animal Poison Control Center. Nationwide Update: Raisins and Grapes Can Be Toxic To Dogs
Tuesday, July 6, 2004. www2.aspca.org/site/News2?id=16645&page=NewsArticle

This has needed to be brought out. Thank you for all of the information. This post has been bookmarked for the future. =)

Thank you so much, Ed, for bringing this up. This is one of the reasons why I'm against the BML diet. I also don't feed raisens or have grapes in my fruit cocktails. I've been asked though by several individuals why and it was always difficult for me to put into scientific enough terms, so this is a thread that is definitely going to be bookmarked.

Yep, bookmarked for sure!

Again - thank you, Ed! Very interesting and informative.

Thank you for this. If I understand it right the hpw powder is ok to use. I've been thinking of changing and have now made up my mind. I will switch to hpw.

Maybe a new BML diest should be created with less iron.

www.sugarglider.com/glidergossip/topic.asp?TOPIC_ID=23393

I found this post. Someone had suggested Candy's recipe that's in the post.

If BML is extremely high in Iron then why is it on this site. I've read BML is great for gliders and the glider that the diet was tested on lived for 10 years. All the info. I got was from bourbons website. So now BML is bad to give to our gliders and if it is can it please be removed from the Resources/Nutrition section?

It's on this site because it's a recognized diet. The reason for this post is to help people make an educated decision about which diet they want to use. Lots of people feel BML is not meant to be fed long term but that it is great for rehabbing sick gliders. It's up to you to read all the info and make an informed decision.

I have only been here for a short while and I have been reading and reading and I can honestly say that I have never read that BML is not good for the gliders long term. I am getting reading to change their diet to the blended diet. I have to say it would have been nice to know that the BML diet used long term was harmful.

Unfortunately most glider diets have been trial and error due to the lack of education concerning the species in captivity. This also holds true for humans, how often is something tested over time and found to have ill effects on our bodies? It stands to reason that while research is still going on regarding sugar gliders, some mistakes will be made.

It's when these discoveries are made that we have to way what is good and bad for our gliders. Thanks to these forums of loving glider owners for years of glider husbandry, without this imput we would still be in the dark.

Since we have no actual recommended amounts of any nutrients needed by sugar gliders and no firm data regarding what is too much or too little of any nutrient or vitamin, we have to go by the results we can observe.

BML has been used for several years and many healthy gliders have eaten it for extended periods of time. If your gliders are doing well on BML - continue using it.

HPW is newer but has also been used for several years with good results - many healthy gliders. If your glider is eating well and healthy on HPW - continue using it.

Other diets are new, including my Blended Diet. We all need to consider the diets we choose for our gliders as an educated choice. The Blended Diet has amounts of calcium, phosphorus, protein, sugar, fat, and fiber between the values of HPW and BML. I did a lot of research to develop the Blended Diet to meet my gliders needs and have shared it with others - along with my reasons for making those choices.

Without scientific studies in controlled feeding situations to actually define the needs of gliders, we are all doing the best we can.

The discussions here about which recognized diet is best, how much of any nutrient is too much or not enough etc are ALL OPINIONS. Those of us that have done our own research and comparisons probably feel that we have more information to share than others. Until we have a real list of nutritional needs, we are all expressing opinions.

I feel all of the recognized diets are good for gliders, experiences of many owners support that.

I do feel new owners who have not looked at the recognized diet and just feed what ever (cheerios, vienna sausage, etc.) may be causing their gliders harm which is why I encourage everyone to choose one of the recognized diets that have been maintaining gliders for extended periods of time rather than trying to invent their own plan.

Like I said, wouldn't it be awesome to have all the answers

That would be nice Prob. going to switch to the hpw diet when their bml is all gone.

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Originally posted by PW

Like I said, wouldn't it be awesome to have all the answers

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<<sigh>> Isn't that the truth...

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Originally posted by LuckyGlider

Now let's put this into context by comparing these amounts to what is recommended for human beings. According to a well-known vitamin expert, Dr. George Obikoya, it is easy for humans to overdose on iron…

"So how much iron do you really need? Iron is not excreted. The iron you absorb stays and accumulates in storage except that you can lose one milligram a day through hair, finger nails, skin cells and other detritus. That is the amount needed every day to replace the loss. One milligram, that’s all and for women in reproductive years, one and a half milligram. The other way to lose iron, of course, is by blood loss." (see footnote 3)

Did you get that folks? HUMAN BEINGS need one milligram per day to keep iron levels where they need to be?

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Interesting topic, I'll have to read Dr. Obikoya's article later to see why he says we only need 1 mg per day. The NIH says the recommended daily value of iron is 8 mg per day for adult men, 18 mg per day for adult women with the tolerable upper intake levels being 40-45 mg per day for both. In addition, the NIH says the need for iron may be 30% greater for those who engage in regular intense exercise (like running on a wheel half the night?) and there is evidence that calcium from diet supplements and foods may inhibit iron absorption.

http://ods.od.nih.gov/factsheets/iron.asp

I think it's great to encourage education and real thinking about the diets we use and wish I could read Dr. Dierenfeld's articles but the large number of owners feeding their gliders BML without apparent ill effect argues that iron toxicity is probably not something to worry about a lot. Remember that life is a stochastic process and there will always be outliers in the population -- human or glider. Frankly, I'll worry more about things that seem to affect a larger portion of the population.