Bioavailable - what is Bioavailable?


Bioavailability refers to the degree and rate at which a substance, typically a drug or nutrient, is absorbed into the bloodstream and becomes available for use by the body’s cells or tissues. Essentially, it measures how much of the ingested substance reaches its target site and exerts its desired effects.

What are the 2 types of bioavailability?

Bioavailability can be broadly categorized into two main types:

Absolute bioavailability: This refers to the fraction of a substance that reaches systemic circulation unchanged after administration via a specific route, typically compared to the same substance administered intravenously (IV), which is considered 100% bioavailable. Absolute bioavailability is commonly expressed as a percentage.

Relative bioavailability: Relative bioavailability compares the bioavailability of a drug or nutrient from one formulation or route of administration to another. For example, comparing the bioavailability of a medication in tablet form versus a liquid formulation, or comparing the bioavailability of a nutrient from different food sources. Relative bioavailability provides insights into the efficiency of different formulations or delivery methods.

Methods to Improve Bioavailability

Food Processing Techniques

Certain cooking methods, such as steaming or boiling, can increase the bioavailability of nutrients by breaking down cell walls and reducing anti-nutritional factors.

Nutrient Pairing

Pairing foods rich in one nutrient with foods containing enhancers of its absorption can improve bioavailability. For instance, consuming vitamin C-rich foods alongside plant-based iron sources enhances iron absorption.


In cases where dietary intake may be insufficient, bioavailable supplements can be utilized to ensure adequate nutrient levels and enhance bioavailability. Supplements often contain nutrients in forms with higher bioavailability.

Importance of Bioavailability in Nutrition

Understanding and optimizing bioavailability is crucial for maximizing the benefits of nutrients in the body. By enhancing absorption, bioavailability ensures that nutrients are effectively utilized for various physiological functions.

Maximizing Nutrient Absorption

Improving bioavailability ensures that nutrients are absorbed optimally, leading to better overall health and well-being. This is particularly important for individuals with specific dietary needs or restrictions.

Preventing Nutrient Deficiencies

Poor bioavailability can lead to nutrient deficiencies, even in individuals with sufficient dietary intake. By addressing factors that affect bioavailability, deficiencies can be prevented, promoting better health outcomes.


Why is bioavailability important in nutrition?

Bioavailability determines how efficiently nutrients are absorbed and utilized by the body, impacting overall health and well-being.

How can I improve the bioavailability of nutrients in my diet?

Consuming a varied diet rich in nutrient-dense foods, utilizing proper food preparation techniques, and considering nutrient interactions can enhance bioavailability.

Are there any factors that can hinder bioavailability?

Yes, factors such as digestive disorders, certain medications, and dietary inhibitors can reduce nutrient absorption and bioavailability.

Is bioavailability the same for all nutrients?

No, bioavailability varies depending on the nutrient and its chemical form, as well as individual factors such as digestive health and genetics.

Can supplementation improve bioavailability?

Yes, supplementation with nutrients in forms with higher bioavailability can help address deficiencies and optimize nutrient absorption.