Monday, February 19, 2007

Pills of... vitamins: fact #1

So OK, we all have done it... In the middle of the night, when the house is quiet, we tiptoed to the drug cabinet and popped in our mouth one or two of those magic pills... Nothing feels really wrong, we just feel we need an extra boost to keep up with our busy schedules... But wait! There is nothing illegal here: those pills were... vitamin pills! Yes!

But what are vitamins?

Vitamins are organic molecules. In chemistry, organic has a different meaning than in our everyday life: it means that something contains carbon*, with a touch of the elements hydrogen, nitrogen and oxygen. This is opposed to inorganic - iron is one inorganic element we need for our well-being.
There are many vitamins around, but they all share the fact that we need them in minuscule amounts, in the order of few micrograms or milligrams per day. That's smaller than a grain of peppercorn. By comparison, a healthy man needs about 50 grams of proteins every day. That's at least 50000 times more than vitamins! I will tell you more about the so called RDI (recommended daily intake) in one of my future posts.

The fact that vitamins are organic molecules has a very important consequence: they are all made by living organisms - you can't find them on the moon. Nope, not even one. So why do people talk so much about natural vitamins? And why there are no unnatural vitamins?

I bet you are confused right now. I would be too. The web does not help either... Read here what I found browsing the net, on a information page (let's call it www.doctor.com - not its real name**) of a company which sells "natural" products:

"vitamin C; ascorbate (food); dehydroascorbate"

is the primary vitamin found in food (according to them, good for us), while:

"ascorbic acid; most mineral ascorbates (i.e. sodium ascorbate)"

is the vitamin analogue in chemical form (according to them, bad for us). Once I stop laughing, I will explain in detail why this classification bothers my conscience.
OK, I regained control of myself. Granted, some people haven't got past chapter one of their chemistry book, and here we clearly have a case.
There are two obvious mistakes here, which I highlighted in bold font (to be honest, there are more just in that statement, but I don't want to write a chemistry book, not yet ;-) ).
I will give you a more familiar example. I do not like vinegar, but many people do. So, the chemical that gives tartness to vinegar is called acetic acid. By the way, there's plenty of it in the salt & vinegar potato chips (I find them too strong for my taste). Acetic acid, being an acid, dissociates in water*** to give two ions: one of them is called acetate (CH3COO-), the other is H+ (AKA hydron, whose increase in concentration makes the pH more acidic). The names ending in ~ate are used in chemistry to identify ions (with a negative charge).
So what happens if I dissolve ascorbic acid in water? Yes! That's it: I have ascorbate and an ion H+. Good, so we now know that ascorbate is just the name of the anionic form of ascorbic acid. So why the www.doctor.com site list them separately? Clearly, it is a mistake! Too bad...

So now we can proceed to solving the second mystery. Where does the sodium in "sodium ascorbate" come from?
This is not more complex to explain, but here we need the help of another friend, the cooking salt (AKA sodium chloride or NaCl). If I dissolve sodium chloride in water it will dissociate in two ions: Na+ and Cl-. This is a characteristic of salts.
So, if I dissolve sodium ascorbate in water, I will have an ion sodium and an ion ascorbate. So again, sodium ascorbate in solution gives the ascorbate ion. What happens to the ion sodium in our bodies? If you have healthy kidneys, it will be eliminated with the urine, as happens every day of our life. The second irritating mystery has been solved.

This classification based on the names of the substances is misleading and therefore should be avoided. Even if I dissolve potassium ascorbate (or any other salt of ascorbate) in water I will have an ascorbate ion, and that is the "active" part of vitamin C.
There is no way a chemist can conceive an explanation for giving different properties to the ascorbate that comes from food and the one that comes from other sources, because they have the same identical structure!

The site contains many more mistakes and it is misleading in other points. It states that the vitamin B2 in commercial pills (but not the ones they sell!) is synthetically produced with 2N acetic acid.
The person who wrote this information is not aware that most companies have switched to a fermentation method (using bacteria as mini-manufacturers) for the commercial production of vitamin B2, which is more cost-effective than chemically synthesizing something from scratch.
To a chemist, "
synthetically produced with 2N acetic acid" only means that a moderately concentrated solution of acetic acid (again, the one in vinegar) was used, but on which substance? And???Fermentation is the process by which some friendly microorganisms take sugar and use it to grow and prosper, and make other useful stuff (for us) in the process. Think about yogurt or bread. In this case, the microorganisms are encouraged to make vitamin B2. This is isolated from the other molecules, concentrated and put into pills.

These examples were enough for me to strongly doubt the validity of all the other information in the web site. I am seriously concerned about the message these persons are sending: don't buy pills from the drug store! Buy them from us! We don't tell you how we make them, but just trust us... They are natural!
Nomenclature of acids and salts is usually in the first chapter of the book. I hate when people use these tricks to induce people to buy their "natural" products.

There is more to say on this topic, but it is not the case to overwhelm you now. I'll wait until next time!

* For those among you who want to know more about this topic, the chemistry of carbon compounds is described in organic chemistry. 

** I apologize for not providing the real links, but to me the problem does not consist in a single page; there are many and this excerpt is just an example.
*** not all molecules are dissociated, but it is a characteristic of this acid.

2 comments:

Kiandra said...

Good for people to know.

Anonymous said...

Thanks for

your sharing, it's very useful