Bioavailability: What You Need to Know

In the realm of clinical care, the term “bioavailability” is more than just a buzzword—it’s a foundational concept that directly impacts therapeutic outcomes. Whether you're recommending a trusted supplement or dietary intervention, understanding bioavailability can help you guide patients toward effective and personalized choices.

What Is Bioavailability?

Bioavailability refers to the proportion of a substance—typically a nutrient or drug—that enters the bloodstream and becomes available for use or storage in the body. For orally administered substances, bioavailability is influenced by how well the compound is absorbed through the gastrointestinal tract and how much is metabolized before reaching systemic circulation—a phenomenon known as the “first-pass effect.”^[1]

For example, magnesium oxide has poor bioavailability and may have laxative effects, while magnesium glycinate offers higher absorption and is preferred by some medical professionals for muscle and relaxation support.*^[2]

Why It Matters in Clinical Practice

A product’s bioavailability can determine how quickly a patient experiences support and how much of a substance is needed to achieve therapeutic effects.

This is particularly important when patients are comparing products or questioning why one supplement may be more expensive than another. A higher price tag may reflect advanced delivery systems—like liposomal encapsulation or chelated minerals—that are designed to improve absorption and efficacy.

Factors That Influence Bioavailability

Several variables affect how well a substance is absorbed and utilized:

●      Formulation: Liquids and sublingual tablets often bypass digestive degradation, offering faster and more complete absorption.

●      Food Interactions: Some nutrients, like fat-soluble vitamins (A, D, E, K), require dietary fat for optimal absorption.

●      Gastrointestinal Health: Conditions like celiac disease or inflammatory bowel disease can impact nutrient uptake.

●      Age and Physiological State: Older adults, pregnant individuals, and those with chronic conditions may have altered absorption.

Professional-Grade Supplements With Excellent Bioavailability

Two examples of supplements that emphasize both targeted formulation and bioavailability are BioLiv and BioThyro from Nutra Biogenesis.

●      BioLiv™ is designed to support healthy bile flow and liver function.* It combines lipotropic nutrients, methyl donors, and liver-supporting herbs like milk thistle and turmeric. These ingredients are selected not only for their individual benefits but also for their synergistic effects that may be helpful for patients who would benefit from a comprehensive formula.

●      BioThyro™ is formulated to support proper thyroid function.* Its blend of thyroid, pituitary, and hypothalamus glandular extracts, along with L-tyrosine, iodine, and selenium, is crafted to optimize bioavailability. It also contains iodine and zinc, which could be beneficial for patients who need these nutrients as well.

Counseling Patients: Practical Tips

When advising patients, consider the following:

1. Route of Administration: For patients with digestive issues, recommend non-oral routes (e.g., transdermal, sublingual, or intravenous) when appropriate.
2. Timing and Pairing: Educate patients on when and how to take supplements. For example, iron is best absorbed on an empty stomach but may cause GI upset, while calcium is better absorbed with food.
3. Product Selection: Encourage patients to choose trusted supplements backed by extensive testing, transparent labeling, and clinical studies when possible.
4. Set Realistic Expectations: Explain that more isn’t always better. A highly bioavailable product may require a lower dose to achieve the same effect as a less bioavailable counterpart.

The Bottom Line

Bioavailability is a key concept that bridges the gap between what patients consume and what their bodies actually use. As a healthcare professional, your guidance can help patients make informed decisions about medications and supplements, ensuring they receive the maximum benefit with minimal waste or risk.

By staying informed about the science of absorption, you can empower patients to optimize their outcomes through a balanced diet and high-quality supplements designed to support their health and well-being.