Bioavailability and Nutrient Absorption in the Body
Digestion is how our bodies process nutrients from the food we eat. It’s a complex series of events where even small inefficiencies can lead to significant issues. Factors like enzymes, the health of our organs, and even how well we chew our food can impact how efficiently our digestive system works. This efficiency directly affects the bioavailability of nutrients, which in turn influences crucial processes like enzyme production and organ function. Everything is interconnected.
Before our bodies can use a nutrient, it must be separated from the food it’s in. This process starts in the mouth with chewing and is aided by the enzymes in saliva. It continues in the digestive tract, where food is broken down into macronutrients and micronutrients. These nutrients are then absorbed by the intestinal lining, transferred into the bloodstream, and distributed for use or storage.
Macronutrients vs. Micronutrients
Nutrients fall into two main categories: macronutrients and micronutrients. Macronutrients include carbohydrates, proteins, and dietary fats. These are needed in large amounts and are essential for tissue growth and providing energy. They are highly bioavailable, with up to 90% being utilized by the body.
Micronutrients, on the other hand, include vitamins, minerals, antioxidants, and certain phytochemicals like iron, iodine, vitamin A, and folate. The bioavailability of micronutrients varies widely. Although the body only needs them in trace amounts, they are critical for health. Enzymes and hormones, which are responsible for the body’s most important processes, rely on these micronutrients. A deficiency in micronutrients can severely impact health, as seen with widespread magnesium deficiency, which is linked to conditions like diabetes, hypertension, dementia, and osteoporosis.
Factors That Affect Bioavailability
Bioavailability can vary greatly from person to person. Two people can consume the same nutrient in the same form, yet their bodies may absorb and use different amounts of that nutrient. Many factors influence individual absorption. For instance, vitamin B12 absorption requires intrinsic factor, a protein in the gut. Without it, the vitamin passes through the body unused. Other factors affecting bioavailability include:
Digestive Disorders
Since bioavailability depends heavily on the digestive process, a less efficient digestive system may not fully absorb and use all the nutrients it encounters. Nutrient absorption rates can range from as low as 20% to as high as 98%. Conditions like Crohn’s disease, IBS, and other inflammatory bowel diseases can severely impact nutrient absorption.
Age
Age is a significant factor affecting bioavailability. Unfortunately, at least half of the children worldwide aged six months to five years suffer from micronutrient deficiencies. Proper development requires the right micronutrients in the right amounts, especially during early infancy (0-6 months) and childhood (6-24 months). This is one reason why breastfeeding is encouraged, as human breast milk is naturally rich in bioavailable nutrients.
Supportive Nutrients
Some nutrients support each other’s bioavailability when consumed together. For example, calcium is best absorbed when taken with magnesium. Consuming vitamin C with plant-based, iron-rich foods enhances iron absorption. This is why a varied, balanced diet is beneficial; a variety of foods provides a diverse selection of micronutrients that support and enhance each other.
In the 1970s, German researcher Hans Nieper described orotates, highly bioavailable natural salts, as part of a natural system of electrolyte carriers that distribute minerals throughout the body. Binding dietary minerals like magnesium, zinc, potassium, lithium, and calcium to orotic acid can improve their bioavailability. Conversely, some micronutrient combinations can interfere with each other. Tannins in tea and wine reduce iron absorption, and phytic acid in nuts and seeds can bind to nutrients and block their absorption.
Why Is Bioavailability Important?
Bioavailability significantly impacts cellular metabolism. Your body has countless cells, each with a specific function, whether they are red blood cells, lung cells, or brain cells. Despite their different roles, all cells need the right nutrients to perform their jobs effectively.
Real Nutrition vs. Synthetic Nutrients
Whole, real, organic food is the best source of nutrition. A well-balanced diet should provide all the macronutrients and micronutrients your body needs. While this sounds simple, it requires planning and isn’t always achievable. Nutritional supplements can help fill the gap between the nutrients you consume and what your body needs, though they are not a replacement for food.
The best nutritional supplements offer plant-sourced nutrients. There is a difference between the vitamins and minerals naturally found in an orange and those synthetically produced in a lab to fortify cereal. It’s recommended to choose organic, food-sourced supplements made in the United States by reputable brands that are transparent about their methods and adhere to the highest industry standards.
