Thursday, January 28, 2010

Vitamins: Supplements Vs. Food

What's in a pill? If it's an oil-based gel cap, it may contain...
  • Gelatin (a protein chemically extracted and refined from skin, bones, intestines, and other organs of cows and pigs)
  • Soybean oil (from genetically modified, omega-6-laden soybeans)
  • Glycerin (from soybean oil, a byproduct of the growing biofuels industry. US makes crude glycerin which is shipped to China and other Asian countries and reimported as refined glycerin.)
... among other carriers, fillers, artificial colors and preservatives, in addition to the nutrient or active ingredient. In the case of fat-soluble vitamins, there's the issue of rancidity.

What if you're cutting back on omega-6 fats, or GMOs, or foods of animal origin? What if your budget is tight? How easy is it to get the RDA from food - for, say, the fat soluble vitamin E? (RDA for vitamin E for adult men and women is 15 mg (22.4 IU) alpha-tocopherol.)

Here are some vitamin E amounts I picked up from NutritionData (serving size, calories, vitamin E mg). In no particular order:A single serving of spinach (32 cal, 3.4 mg), tomato sauce (30, 1.8), squash (41, 1.3), red pepper (23, 1.2), broccoli (27, 1.1), and almonds (162, 7.4) consumed in a day would meet the RDA, at 16.2 mg vitamin E for only 315 calories.

I often think since vitamin E is a fatty vitamin there wouldn't be appreciable amounts in non-fatty foods. Here's a chart from the data above that shows many low-fat, low-calorie foods have more vitamin E per calorie, that is, are more nutritionally dense, than higher-fat foods:

Click to enlarge.

For the case of vitamin E at least, foods may have the edge over supplements.
Photo of vitamin E and Chart: Bix


caulfieldkid said...

I also have to question the RDA. If I'm eating a varied, healthful diet, I have a feeling I'm getting what I need. Maybe that's rather naive of me, but I just don't see how hitting all those numbers are going to make me significantly healthier. There may be cases where you find you have a deficiency. No problem, make some dietary adjustments and move on.

I'm being overly simplistic, but it's been one of those days. . .


Anrosh said...

i think we should go in for vitamins only if the body due to a medical condition cannot absorb the vitamins from real food - don't you think ?

dietary supplments otherwise is a matter of trade and economics -

ferociously ambitious men and women who are genius and crooks at the same time find different ways and means to find market for anything and everthing !

Bix said...


You're right. The RDAs and DRIs have factors applied to them. They, the IOM, Institute of Medicine, who creates RDAs, sometimes take the highest dose that a particular group does well with, say healthy adolescent men, and multiply that by a factor, maybe 2. And then apply that to other groups who may not need that much. It's a margin of safety. RDAs have buffers.

There's something else working too - that helps us get more nutrients from foods if we need them. It has to do with absorption. Nutrients are absorbed in various ways. Sometimes they get absorbed through simple diffusion, so that if there is a steep gradient, you absorb more. That is, if your body stores are low and what's coming down your intestines from food is high, that's a steep gradient and you'll absorb more.

Another form of absorption uses energy (diffusion doesn't). Calcium is interesting in that, when our body stores are high, we absorb what comes down the pike via simple diffusion. But if our body stores are low, we expend energy (in the form of ATP), that is, we force more in than would naturally move along a gradient. That is why some people who eat very little calcium, 200 or 300 mg a day, can have good body stores.

There are lots of other factors. But I agree with you, as you said, a varied, healthful diet generally fulfills our needs.

On the other hand.... (see @Anrosh)

Bix said...


You took a careful position there - go in for vitamins sometimes. That's about where I stand. Unfortunately, many of us just don't eat a varied and healthful diet. I think supplements can fill a void. They're not as good as food, but they're better than not getting certain nutrients at all, or getting too little.

Vegans don't get enough vitamin B12 or zinc. People who eat food that creates a high renal acid load (a high PRAL, meats/dairy/grains do this) probably need more minerals, like calcium (although see my reply to shaun) to neutralize or buffer the low serum ph. There's a good argument for more vitamin D for people who aren't making it in their skin or are losing it in other ways. Air pollution and smoking increase our need for vitamin C.

This is my area of study but for others it's not something they think about. (Which is great because I depend on others' areas of study, like building and fixing cars.) So, some supplements are helpful for some people. But which ones? And how much? This is why the work of the IOM who makes these decisions is important. It's vital that they be as objective as possible. Because you're right ... the supplement business is scamming a lot of people.

Anrosh said...

Another reason for vitamins -

bioenginnered foods.

Monsanto is creating a havoc everywhere, - now it is organic alfa alfa, before that it was corn and cotton. it seems in india it is eggplant now ( we call it brinjal) --- If there is going to be more poison on the plate, there is more room for vitamins - don't you think ?

we have still not proven vitamin tablets have side effects - do they ?


Bix said...

Do vitamin tablets have side effects? Yes. They certainly do. There's a risk not only from high doses of the active ingredient, say vitamin A or iron, but there's a risk from contamination, e.g. pesticides.

Speaking of genetic engineering, many vitamins are encapsulated with genetically modified soybean oil.

Still, there's a cost:benefit for everything.

Suzanne said...

I posted today about our family's food policies and thought of you. I haven't dropped by in ages, as my monkey-wrestling duties (aka parenting) have been arduous of late.

I like your Bites feature. This Vit E article is useful to me. I'm wondering about this, though: "For the case of vitamin E at least, foods may have the edge over supplements." Is it not usually the case that food trumps pills?

pure said...

I take supplements to protect myself from disease and illness because taking vitamin supplements give us a kind of immunization against any illnesses.