(I'm probably going to get blasted for this one, but I am writing it anyway.)
No-one wants to hear that a Healthy Diet has Evils. Actually, it was hard to find a clear definition of what constitutes a Healthy Diet, let alone what constitutes Good and Evil therein. But I found a definition and I have found two Evils, which can work together, and -with a bit of assistance from your well-intended and unsuspecting
primary physician, can cause a pretty serious problem over time.
WTF are you talking about, OSM? I hear you ask.
I'm talking about B12 deficiency.
Don't be daft, OSM, (I hear you say) there is plenty
of B12 in a healthy, balanced diet.
Is there? Show me. OK. scratch that. I'll show you that there might not be sufficient B12 in a healthy diet.
...what exactly constitutes a healthy, balanced diet, anyway? I tried to
find a definition or example online, and could find very little. I did find this:
Clinical nutrition definition: Any
diet based on sound nutritional principles; the HD philosophy is often coupled
with the belief that organic and/or unprocessed foods–ie, produced
without pesticides and chemical preservatives, are superior to adulterated
foods
Healthy
diets, features of
• High consumption of fruits &
vegetables
• Low consumption of red meat &
fatty foods
• Raw foods & whole grains are
preferred to processed or refined foods
• Protein primarily from fish, dairy
products, nuts
• Consumption of salt, pepper,
sugar, coffee & other caffeinated beverages, and alcohol, is discouraged
OK that sound fair enough, it echoes what most of me doctors have told me: Lots of vegetables and whole grains, low on red meats, fats and chemicals.
Here is a list of some B12 sfood sources from the National Institute of Health (NIH). I figure they should know, right?
Table 1: Selected food sources of
vitamin B12
|
Food
|
Micrograms
(μg)
per serving
|
Percent
DV*
|
|
Mollusks, clam, mixed species,
cooked, 3 ounces
|
84.1
|
1400
|
|
Liver, beef, braised, 1 slice
|
47.9
|
780
|
|
Fortified breakfast cereals,
(100%) fortified), ¾ cup
|
6.0
|
100
|
|
Trout, rainbow, wild, cooked, 3
ounces
|
5.4
|
90
|
|
Salmon, sockeye, cooked, 3 ounces
|
4.9
|
80
|
|
Trout, rainbow, farmed, cooked, 3
ounces
|
4.2
|
50
|
|
Beef, top sirloin, lean, choice,
broiled, 3 ounces
|
2.4
|
40
|
|
Fast Food, Cheeseburger, regular,
double patty & bun, 1 sandwich
|
1.9
|
30
|
|
Fast Food, Taco, 1 large
|
1.6
|
25
|
|
Fortified breakfast cereals (25%
fortified), ¾ cup
|
1.5
|
25
|
|
Yogurt, plain, skim, with 13 grams
protein per cup, 1 cup
|
1.4
|
25
|
|
Haddock, cooked, 3 ounces
|
1.2
|
20
|
|
Clams, breaded & fried, ¾ cup
|
1.1
|
20
|
|
Tuna, white, canned in water,
drained solids, 3 ounces
|
1.0
|
15
|
|
Milk, 1 cup
|
0.9
|
15
|
|
Pork, cured, ham, lean only,
canned, roasted, 3 ounces
|
0.6
|
10
|
|
Egg, whole, hard boiled, 1
|
0.6
|
10
|
|
American pasteurized cheese food,
1 ounces
|
0.3
|
6
|
|
Chicken, breast, meat only,
roasted, ½ breast
|
0.3
|
6
|
Have a serious look at that list. Now take out the breakfast cereal, because
I am pretty sure that's a red herring and then honestly add up how much B12 you
consume in a day. Notice that a serving of chicken breast: that vaunted staple of The Healthy Diet, contains only 6% of the Daily Value of B12. A cup of milk (8oz) only 10% and a cup of yogurt, which is two of those little 4oz
carton thingys BTW, contains 25% of the DV.
So -breakfast cereal aside (because I am going to come to that in a minute), were I to try and to get adequate B12 from food, according to this chart from the NIH, I would need to eat all this:
|
Food
|
Percentage DV
|
|
2 eggs
|
20%
|
|
A pint of milk (2 8oz cups)
|
30%
|
|
3oz (one little can) of tuna
|
15%
|
|
Two half chicken breasts, roasted
|
12%
|
|
1 cup plain skim yogurt (which I hate)
|
25%
|
|
Total
|
102%
|
This brings me to 102% of the daily value. OK fine. Better
to be slightly over than under. And remember, I would have to eat all this in ADDITION to my veggies and wholegrains, which contain virtually no
B12.
That's a lot of food. I don't eat three servings of protein
AND two eggs AND all that milk and yogurt in one day! I don't
know who does. And in order to get adequate B12 from food, I would need to eat like that every single day. Actually more for me. Because I am recovering from a B12 deficiency, I need more B12 than the average Joe.
I can raise my B12 intake by eating Unhealthy food; steak, a taco or a burger all have much higher B12 than the healthy food. But then me Healthy
Diet is blown.
...and now we understand the title of this piece.
Yes, there are better
sources of B12 on the list and you may say that I deliberately ignored them. But I can't tell you the last time I served my children wild rainbow trout for dinner, or indeed when I was a Mean Mom and had the audacity to serve farmed rainbow trout for dinner on a school night. Oh wait. I suddenly remembered when:
It was Never. On both
counts.
We do eat tuna, which is a pretty low source of B12, but not too much salmon, which is a much
better source. And both kids would probably
run a mile if presented with a mollusk (although Grace will eat scallops) or a
piece of liver.
So that leaves "unhealthy" food.
Now, I know most of you have probably looked at this list, zeroed in on the 'fortified breakfast cereal', then relaxed, with the
thought I eat me Special K every
day. I'm fine.
Are you?
Let's explore that for a minute.
I was quite amazed, when researching this subject to find
differing opinions on the recommended daily amount of B12 a healthy adult should
intake. Here is an excerpt from the NIH page where I got that daily value grid.
The DV for vitamin B12 is 6.0 micrograms
(μg).
This is from the next paragraph, on the exact same page:
Table 2: Recommended Dietary
Allowances (RDA) for vitamin B12 for children and adults [7]
|
Age
(years)
|
Males
and Females
(μg/day)
|
Pregnancy
(μg/day)
|
Lactation
(μg/day)
|
|
1-3
|
0.9
|
N/A
|
N/A
|
|
4-8
|
1.2
|
N/A
|
N/A
|
|
9-13
|
1.8
|
N/A
|
N/A
|
|
14-18
|
2.4
|
2.6
|
2.8
|
|
19 and older
|
2.4
|
2.6
|
2.8
|
So which is it, NIH?
Is it 6 micrograms or 2.4 micrograms?
Because that is a big difference! The 6 mcg number comes from the FDA,
BTW. The 2.4 mcg number comes from the
Institute of Medicine. Personally, I prefer the FDA number. I'm going with that one
for me and my kids. But here's the problem I have now: Which number was used in the food values table
above? The FDA number or the IOM one?
As 0.6mcg=10% of DV on that table, it must be the FDA number. OK fine.
Then I looked at me
box of special K:
|
|
Cereal only
|
Cereal with ½ cup vit A&D fat-free milk
|
|
B12
|
100%
|
110%
|
|
Folic Acid
|
100%
|
100%
|
These are only percentages. There no values in micrograms.
So I don't know if this figure is 100% of the FDA-recommended 6 mcg or of the IOM-recommended 2.4mcg. There
is a big difference between the two, right? Reading all the small print of the box I see
"The Institute of Medicine suggests...." So I figure the numbers are
IOM numbers. Therefore, the cereal does NOT provide 100% of my FDA recommended
daily value. And also, that first NIH table,
with the food values:
|
Fortified breakfast cereals,
(100%) fortified), ¾ cup
|
6.0
|
100
|
...is wrong! That's
the FDA number, but Kellogg's are using the IOM one. Therefore, that line should read 2.4mcg and 40%. For special K, at least.
I had a quick look online at the B12 value for Cheerios and again, no hard numbers, just percentages. This time the precentage was 25% without milk and 35% with milk. This time there was neither reference to the FDA or the IOM that I could see, so I have no idea which guideline they are using. For me the point is
moot because we don't really eat fortified breakfast cereal in this
house. The Special K box that I used as an example here had been sitting there
for ages! But if anyone out there is using fortified cereal as a means to keep their B12 levels propped up, just be sure you understand what those numbers actually represent.
Regardless of whether the recommended amount is 6.0 or 2.4, I figure that many of us who are trying to eat a
healthy diet are not getting our full quota of B12 every day, (while the people scarfing down steak, burgers and tacos are doing much better on the B12 front!). But that's OK, right? If any of us are B12 deficient, the doctor will
catch it in the annual physical (because
we all go for our annual physical right after our birthday, right)? That's our safety net. The annual physical.
Maybe. Maybe not.
The Mean
Corpuscular Volume (MCV) test in the standard CBC
is the method most doctors use to measure your B12 levels. It is an indirect measure: The science
behi
nd it is relatively simple: If B12 levels are too low, the red blood cells
(RBCs) start coming out wonky. Instead
of being a nice, neat doughnut shape, like in this picture on the left, they are bigger and uneven with lumpy bits
(that's a medical term!), like the picture on the right. Personally I don't see too much of a difference, but that's probably why I don't work in a lab...
There are a few problems I see with this MCV approach for detecting dietary B12 deficiency:
1 Folic Acid (will explain in a tick).
2. The human liver can store up to four years worth of B12, so by the time your red blood
cells are coming out wrong, your diet will have been deficient for years.
3. Making red blood cell is not B12's only job. B12 also
makes myelin, the stuff your nerve cells need in order to transmit signal
properly: Multiple Sclerosis is disease in which myelin is effected; so yeah. We need it. A lot. And by the time your
blood cells start showing problems, the myelin could have been in trouble for a
long time.
4. There is a perfectly good test available that will directly measure blood serum
levels of B12.
Sorry, wrong Superhero.
In 1998 the FDA required that certain manufacturers of grain staples like bread and cereal should add
Folic Acid to their product. Folic Acid
(B9) is like a Vitamin Superhero. It does lots of things in the body. It is
most famous for preventing spina bifita in babies if taken by women prior to
conception and during pregnancy. In
fact, Folic Acid is such a superhero, that if your B12 levels are low, it will
step in and help those little blood cells to stay healthy and doughnutty.
However, sending Folic Acid to do B12's job is problematic.
Because if Folic Acid is a superhero, it
is like the Batman of Vitamins. Well meaning, with lots of tricks up it's
sleeve, but ultimately human. Batman
can't fly. He can jump, glide and absail. He fakes it pretty well, but it isn't
real flying.
B12 is more Like the Superman of vitamins. He doesn't need tricks
or gadgets. He can fly.
B12's primary Superman trick is that it makes myelin. Folic Acid just can't do that. So if your B12 is low or missing, and your Folic
Acid is high -and it often is for those
of us who like to eat healthy, because we pile on those leafy green vegetables- Folic Acid will do it's very best to take
over B12's job where it can: In the blood cell department. Unfortunately, your myelin is on its own. Because
Folic Acid can't fly.
So remember that blood test, the MCV that the doc will use
to indirectly check your B12 levels? It
is now actually useless for that
purpose, and could even be dangerous, because Folic Acid is taking up the slack with the blood cells, but not with myelin.
That is the second secret evil of a healthy diet: Too much folic
acid may mask B12 deficiency.
You need a serum B12 test to really know your B12 levels.
Don't bother faffing around with MCVs for that purpose. I'm serious.
What does B12 deficiency feel like?
Now all this -especially the folic-acid-masks-B12-deficiency
thing this isn't scientifically proven. Yet. They are starting to find some stuff; see this, this
and this. It is relatively early days yet.
Most people can store about 4 year's supply of B12, so it will take a
long time for a dietary deficiency to become apparent. And B12 deficiency is sneaky and unobvious. For
me, it started as fatigue and these hideous mouth ulcers that I used to intermittently
get all along one side of my mouth and throat.
I didn't notice that I was losing feeling in my hands until
I burned my hand and didn't feel it. -I didn't
flinch at all, but I SAW my hand was burning and pulled it off the grill (ended
up with a lovely blister about an inch across). If that accident hadn't happened, I don't know
when I would have realized there was a problem. Other people who have had B12
deficiency will say the same thing: That it snuck up so slowly and they didn't realize
there was a big problem until it was well advanced.
Because most people do what I did when I first started to
feel tired. I blamed myself. I figured. I am unhealthy. I should eat better:
More fruits and vegetables, less fast food and less red meat...
See the vicious cycle?
This is why we should go to the doctor, people.
... and ask for the correct
test.