What is bioavailability?
And why is it essential for nutritional supplements?
Sooner or later, if you are exploring the world of nutritional supplements you will come across the term ‘bioavailability’. It sounds slightly off putting, but is actually an extremely important factor in whether supplements are effective or not.
Like many scientific terms, it is better understood if it is broken down so it can be absorbed more easily. Which is rather appropriate, because that is essentially what it means!
Bioavailability is the rate at which a substance – which could be a nutritional supplement or a drug – is absorbed into a living system. 1
Why is that important in relation to supplements? Because the efficiency with which the core elements of that supplement – whether that’s vitamins, minerals, enzymes or herbs – find the part of the body they are going to help means that they well be delivering more help, more quickly.
Supplementation is usually managed by taking supplement capsules or tablets. They are swallowed, and then digested: just like food, they turn up in our digestive tract and then head out through the wall of the intestine into the bloodstream, and through some amazing nutritional GPS find their way to the system or organ in our bodies that they are intended for. Only then can they start working for our benefit. So, the faster and more effectively they do that, the better for us. Some supplements are ineffective precisely because they never fully get absorbed into the body.
One thing to be aware of: manufacturers of supplements often claim that they have created a product with maximum bioavailability. But it’s not as simple as that. There are two elements at work; the supplement itself and your body.
As far as the supplement is concerned, critical factors include the form it comes in, how long it takes to break down – in other words how quickly the essential contents can get to work – as well as the quality of the ingredients and their formulation. Some nutrients are better absorbed when they are paired with other nutrients. As an example, a calcium supplement might also include Vitamin D, which is shown to increase the body’s absorption of calcium. 2
The other part of the equation is you. Your body is individual – every human being is different. So, however bioavailable a nutritional supplement is in principle, the other factors that come into play are those of the person taking the supplement.
And that involves a range of factors: from your age and gender, overall health, the state of your digestive system (which in passing can also be supported with the right supplements), the time of day the supplement is taken to whether your stomach is empty or full. That’s a lot of variables!
On top of that we have to bear in mind your nutrient needs: growing children or graciously aging adults and pregnant women – all have different requirements which impact on how easily a supplement will be absorbed.
Of course, you can always ask the manufacturers of the supplements you’re interested in. Ideally, they will be ahead of you and be proactive in promoting the bioavailability of their products. You can also do a little research online about some of the optimal combinations of nutrients you should look for.
Behind all the science, the key thing here is pure common sense. The sooner you can absorb all the good things in supplements, the sooner they can start making a difference to your health and energy levels. So, by taking a little time to understand how bioavailability works you’ll be that much closer to making informed choices about combinations to suit you!