Robert Green 04.01.03
The Laboratory Notebook
Answering important questions about quality.
By Robert Green
Thanks for sending in your questions. This month we address vitamin A issues as well as an analytical lab’s responsibility when its findings are the subject of a dispute.
Q. I am formulating a vitamin A capsule and am not sure if I should use true vitamin A or beta-carotene. Can you discuss this issue?
A. Vitamin A is a critical and thus popular vitamin. It was the first vitamin officially named, and that’s why it got the letter “A.” (Now there’s a bit of trivia you may not have known). It is a fat-soluble vitamin that actually comes in two forms. It is found in its true form in animal foods such as fish oils and liver as retinal, so named because of its importance to vision—the body readily uses this form.
Several carotene pigments found in foods, mainly yellow and orange vegetables and fruits, can be converted to vitamin A in our body and thus are termed provitamin A. Beta-carotene is the most available and also the one that yields the highest amount of vitamin A. Beta-carotene must be converted in the body to be used by it.
Vitamin and mineral amounts are usually expressed in milligrams (mg) or micrograms (mcg). However, vitamin A values are expressed as international units or I.U.’s. For example:
1 I.U. = .6 mcg beta-carotene
1 I.U. = .3 mcg retinal
As can be seen from these conversions, one unit of retinal equals two units of beta-carotene. Therefore, with two excellent sources of vitamin A, a common question is, “Which form should I use in my capsule?” There is probably no absolute answer. You obviously need one-half the amount of retinal as you do beta-carotene, so that sounds like the winner. However, retinal is very unstable and many claim the body does not absorb the full retinal dose, so you may receive a greater amount of vitamin A from ingesting the beta-carotene equivalent. Another factor to consider is cost. Beta-carotene is significantly less expensive than retinal, so it may be economically beneficial to add the greater amount of beta-carotene.
Q. As a responsible seller of nutritional supplement raw materials I had a supply of material tested by an independent testing lab and received a report affirming that the material met specifications. I then sold the material to a third party who had a sample tested by another testing lab, which reported that the material failed to meet the stated specifications. I now have a problem since the buyer wants to return the material. I asked my lab to help support its findings (and hopefully discredit the negative analytical report), but I am not getting any cooperation. What is the responsibility of my lab in this circumstance?
A. This is not the first time we have heard about or seen this problem. Our analytical work spans several industries. Analytical chemistry in the nutritional supplement industry is an anomaly. Take, for example, the pharmaceutical industry. A lab that keeps the methods it uses secret, does not readily provide analytical data and refuses to cooperate when an analytical issue arises, would be out of business in short order. This is not so in the supplement industry.
Basically, there are no rules, regulations, performance criteria or other directives governing the operation of an analytical lab conducting nutritional supplement testing. This means that the general rules of commerce apply: let the buyer beware.
Anyone can open an analytical lab (and anyone has), and they can conduct themselves as they see fit. This means the consumer must do his/her homework. Otherwise, at the most inopportune time (usually when a problem arises) you may find yourself without analytical support.
An analytical lab’s responsibility to support its clients arises from two principles: professional responsibility and customer service. In terms of professional responsibility, if a lab is charging money to conduct an analysis it has a professional responsibility to support that analysis. This is even more so when a dispute arises because a client relied on that work. At a minimum this means providing sufficient information to prove the validity of the analysis. This includes disclosing the source for the analytical method used. Sources include the USP, AOAC or the peer-reviewed journal article in which the method is disclosed. Without this information the lab’s analysis bears no weight. Remember, disclosure of the method means providing information in sufficient detail, so another lab with reasonable skill can duplicate the analysis. A lab disclosing that it used a method that is identified only by numbers or letters (i.e. Method 1234) is both meaningless and valueless.
In addition, the lab should disclose the actual data generated during the analysis. Virtually all modern analytical instrumentation records the data generated and that data is used to determine the sample’s characteristics that result in a product analysis report. For example, every HPLC analysis results in a chromatogram. A lab client paid for that data so it has a right to it. This data is critical to support a lab’s findings.
While the above information is required to fulfill a lab’s professional responsibility, it still is not enough. Most clients do not possess the necessary skills and experience to evaluate and then debate the selection of the analytical method used and the interpretation of the generated data. That’s why they went to an analytical lab in the first place. So if a lab wants to provide adequate customer service, it needs to do more. The lab should fully explain to the client why the method was selected, why that selection was appropriate and how the data was interpreted. We go one step further. When a dispute about our results arises we suggest the client put us directly in touch with the other party’s lab and we take it from there.
The lesson here is to find out if you are using a professional lab that provides customer service before you need it. Otherwise, you may learn the hard way that the analytical report you paid good money for is not worth the paper it is written on.NW