Absorption: Tablets Versus Liquids
Tablets Are For Adults; Liquids Are For Children
I am so fed up listening to all the claims of supplement manufacturers who make liquids as to how they are better absorbed by your system. Nothing could be farther from the truth and in this article I will try and explain exactly what is meant by absorption and bioavailability. If you take prescription drugs you know that the majority of them are in tablet form and we all know how well they work, including all the side-effects. So why spend much more money to drink liquids that cost so much more than tablets and capsules and because of spillage, you never get exactly the same dose twice.
Many liquid manufacturers refer to a study that was done many years ago and published in the Physicians’ Desk Reference about liquid supplements being more bioavailable. The statement was eventually removed from this reference book because it could not be substantiated.
Nutrients are typically absorbed by the small intestine (unless they are taken sublingually or injected). When you ingest a supplement in either liquid or tablet form, it must first pass through the stomach before reaching the small intestine. If liquids were simply absorbed into the bloodstream as some supplement manufacturers claim, what would happen if you consumed a bowl of soup? Would it also be absorbed directly into your bloodstream?
Bioavailability is defined as the degree and rate at which a substance (as a drug or supplement) is absorbed into a living system, or more correctly, the degree or rate at which it is ultimately made available at the site of biological activity. Different vitamins and minerals have different absorption rates regardless of whether they come from a tablet, liquid, powder or food. Calcium, for example, has a fairly standard absorption rate (25-35%) and the form it comes in will generally not make any difference.
A well-made tablet provides a very effective delivery system and is the chosen form of most pharmaceutical medications. This has been substantiated over years of study so why should supplements be any different. If you take an 81mg aspirin every day, do you think it would be more effective in a liquid form? Of course not; only more expensive.
Because of compression, a tableted product can provide an increased amount of active ingredient (almost 3 times as much as a capsule and much more than a liquid or spray). Also tablets are far more stable than liquids or sprays.
Bioavailability is a complicated topic because it is not dependant solely on product formulation. Many external factors can affect the absorption of supplements and other compounds. Some of these factors are age, digestive system integrity, overall health status, time of day, gender, and if the product is taken on a full or empty stomach. Some people are fast metababolizers and others metabolize very slowly. Growing children and pregnant women will have significantly enhanced absorption because of certain needs for certain nutrients.
Recently some supplement companies have made claims that their products are superior because they are “98% absorbed” or some similar number. This is a misleading statement because there are far too many variables to imply that an individual’s absorption is a certain per cent of the material consumed. Even absorption of minerals from food sources can vary significantly. Boron, molybdenum and iodine can be absorbed at over 90 per cent, while the average absorption rates of zinc, copper, and selenium range from 30 to 80 per cent depending on the form. As such, stating an absolute absorption rate is almost always misleading.
If you actually look at supplement studies, the majority of them use tablets because liquids and sprays will never give them good results. So how can anyone say they are superior? Again, as I said earlier, the best place for liquids is with children who may have difficulty swallowing capsules or tablets.
I saved this one for last because this is my favourite example of the misleading information thrown at consumers. Many supplement manufacturers claim that liquids are better because they do not contain fillers (excipients used in tablets for disintegration, form, binding, coating, etc.) This is so illogical because liquid supplements require more “ other” ingredients including emulsifiers, solvents, preservatives, stabilizing agents, colouring, flavouring and more. Generally speaking, the more ingredients there are in the liquid preparation, the more excipients that product will require.
Pharmaceutical manufacturers would not use tablets unless they were the most cost –effective and most efficient method of delivering the drug to the area needed. Do not be fooled by all these false claims. If the product comes in a tablet form, buy it and save yourself a lot of money.