The debate about bioavailability of dietary supplements focuses on absorption. Since dietary supplements are NOT pharmaceuticals, there is no requirement to access for disintegration. Tablets are made by mixing ingredients and compressing them with additives to form a specified size and shape. Tablets are lower in cost, offered in elegant sizes and shapes, and may have enteric coatings to reduce gastrointestinal irritation. But the excessive compaction from pressure processing leads to poor bioavailability and many pass intact into the feces.
Capsules usually have vegetable source shells that protect the nutrients from acidification in the stomach. They are easier to swallow with reduced gastrointestinal distress but capsules are more difficult to fill, which increases cost.
Gummy supplements may lead the way in taste and acceptance but any nutrient in them is exposed to the harsh stomach environment for denaturation and the gooeyness on the teeth can promote dental issues.
The Association of Official Agricultural Chemists (AOAC) is continuing to help the dietary supplement industry agree on and evaluate analytical methods to ensure quality, safety, and regulatory compliance. Twenty-five “priority ingredients” have been chosen to be evaluated by the 131-year-old AOAC organization under a contract funded by the National Institute of Health (NIH), Office of Dietary Supplements . More information is available on the AOAC website: www.AOAC.org.