Trying to understand DV % on micronutrients

mactira
mactira Posts: 5 Member
edited March 2019 in Food and Nutrition
I'm sorry if this is basic info but I've never looked into it before. I'm trying to figure out how to get my meals set so I get the right potassium, iron, etc but I'm kind of lost on this. Let me give you an example.

I'm a 50+-yr-old male. As such, I believe the USRDA for iron is 8mg. When I look up the iron content of several different items such as a tuna can in my cupboard or something in my fridge, I get a % of DV like 4% or 8%. When I look up the mg of iron somewhere else, I get something that doesn't even come close to being that % for a daily 8mg amount.

For example, for my Irish Oats, it states that it has 8% of my daily needs of iron, but it also says it has 144mg of iron.

8% of 8mg would be .64mg, not 1.44mg.

1.44mg/8mg is actually 18% of recommended, not 8%.

When I look at things in my home, I usually only see a % like 2, 4, 8, etc but it looks like I can't just use that as a % of 8mg. Same thing for other micronutrients.

What am I doing wrong?

Replies

  • lemurcat2
    lemurcat2 Posts: 7,885 Member
    Looks the the DRV % is based of those with the highest needs (women before menopause) -- 18 mg.

    I suppose you could figure your percentage of that and just make sure you hit that percentage.

    My suspicion is that unless you have significant dietary restraints, your dietary iron will be fine without watching it, and a simpler approach is to just have it tested to make sure there's no issue. Iron needs vary -- some eat plenty and yet end up anemic, whereas some tend to hoard it too easily and can get an excess (which can be damaging, its why no one should supplement iron without a medical reason, IMO).
  • cmriverside
    cmriverside Posts: 34,416 Member
    Iron is one of those things that if you are actually low on it, you'll have symptoms.

    I don't sweat the small stuff because I have good iron levels when I get bloodwork done and the couple times I did have low iron I was super fatigued and knew something was wrong.

    If you are in a First World country you really are likely fine on iron levels. All grains are good sources, so is red meat, seafood. I wouldn't worry about it.
  • lemurcat2
    lemurcat2 Posts: 7,885 Member
    Dilvish wrote: »
    Also look out for Sodium (which is lighter than actual salt, salt being twice as dense).

    ???

    Salt is sodium chloride (NaCl). It's about 40% sodium. A tsp of salt has about 5 g (or 5000 mg) of salt. That includes about 2000 mg (40% of 5000 mg) of sodium.

    On the other hand 2 g (or 2000 mg) of sodium = (of course) 2000 mg of sodium.

    Don't know what this has to do with salt being heavier or denser than sodium -- 2000 mg of salt is the same weight as 2000 mg of sodium alone.
  • hypocacculus
    hypocacculus Posts: 68 Member
    The problem with the amounts of vitamins and minerals stated on food packets is that they are just a generalised value for that foodstuff, not a guarantee that that particular portion contains that amount; it can vary wildly. Furthermore, the way in which you absorb vitamins can be affected by the other foods you have eaten them with. Vitamin C helps you absorb iron for example; or large amounts of spinach can result in less iron being absorbed because of it's oxalate content.

    It's enough to make your brain explode. Personally I'd not worry too much and just try and eat that balanced, healthy diet dieticians are always banging on about.

    Everything in moderation :-)






  • kshama2001
    kshama2001 Posts: 28,052 Member
    cmriverside wrote: »
    Iron is one of those things that if you are actually low on it, you'll have symptoms.

    I don't sweat the small stuff because I have good iron levels when I get bloodwork done and the couple times I did have low iron I was super fatigued and knew something was wrong.

    If you are in a First World country you really are likely fine on iron levels. All grains are good sources, so is red meat, seafood. I wouldn't worry about it.

    Yes, @mactira if you are super fatigued do ask your doctor for blood work to rule out iron or other deficiencies.

    But as a man you are probably fine if you have no history of anemia and are an omnivore, or if you are a pescatarian who also eats the foods listed https://ods.od.nih.gov/factsheets/Iron-HealthProfessional/
  • mactira
    mactira Posts: 5 Member
    Thank you all for your help. The 18% comment above definitely made the logic work out in my head. I'm now back in a first world country so I can get all the food I need but just want to go about it logically. I've never tracked my food or nutrients in my life so this is all kind of a revelation. I'm hoping I can somehow get bloodwork done at the VA to see if I'm really low on anything.
  • kshama2001
    kshama2001 Posts: 28,052 Member
    edited March 2019
    mactira wrote: »
    Thank you all for your help. The 18% comment above definitely made the logic work out in my head. I'm now back in a first world country so I can get all the food I need but just want to go about it logically. I've never tracked my food or nutrients in my life so this is all kind of a revelation. I'm hoping I can somehow get bloodwork done at the VA to see if I'm really low on anything.

    I'm with the VA too. Sometimes I have to aggressively advocate for myself, but by-in-large, I've gotten everything I need.

    VA doctors aren't as quick to say yes to requests, so I do more prep before visits than I did when I had Blue Cross & Blue Shield.

    But you explaining that you are 50, want to take a more active interest in your nutrition, and want to get tested to see if you have any deficiencies is a perfectly reasonable request.

    When I moved back to MA from FL and wanted to get tested for Vitamin D deficiency she had no problem ordering that. (And it turned out I was indeed deficient.)

    However, one has to ask for these sorts of things - they are not routine. Despite being first diagnosed with anemia when I was 19, I have to ask for that to be included in my routine blood work.

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