Top 10 Things to Know About Bioavailability
Ever wondered why there isn’t a strict nutritional protocol that everyone follows? One reason that this does not exist is because of the variation in ways our bodies handle nutrition. So many variables exist.
When all goes well, you may not give much thought to how your body is processing and absorbing your food. But we love to think about it. We often talk about balance and harmony, because nutrition isn’t about achieving some “maxed out” state as much as it is about getting the proper amounts of needed nutrients to look and feel your best. Maybe that’s why we’re practically obsessed with the topic of bioavailability.
Bioavailability:
"The fraction of an ingested nutrient
that becomes available for use
and storage in the body"
- R. Gibson
1. Generally speaking, in nutrition, bioavailability represents the degree to which something you eat or drink is absorbed.
Bioavailability is a term that can be used in pharmacology, nutritional science or environmental science. The principles of bioavailability apply to pharmaceuticals, dietary supplements, herbs and other nutrients. It’s important to note that, for now, drugs are more widely studied and held to a more strict standard regarding absorption rates than are nutrients of foods or more natural substances. Nutrition science is relatively young and many factors are still being investigated.
2. Nutrients are absorbed by the body several ways.
We absorb nutrients in five basic ways: we chew, churn, contact, move in the bloodstream, and process at the cellular level. Our bodies break down the vitamins, minerals, carbohydrates, proteins, and fats in food to use these components at a cellular level. It starts when chewing triggers saliva to enter your mouth and salivary enzymes to start breaking down food. As you swallow the crushed food, the components churn and mix with the gastric acid in your stomach. Next, these nutrients make contact with the small intestine, aka “nutrient absorption center.” Then they enter the bloodstream. Finally, carrier proteins bring nutrients into the cells.
3. There are many factors influencing bioavailability.
Factors may include:
- whether a drug or supplement is taken with or without food
- the kind of food you eat
- metabolism
- gastrointestinal health and function
- intestinal motility / gastric emptying rate
- intestinal microflora
- liver metabolism
- physical properties of the supplement
- circadian differences
- interactions with drugs, antacids, alcohol, nicotine
- enzymes in the body
- age
- sex
- states of disease (especially if affecting the liver or kidney).
4. Nutritional supplements provide benefits that are variable due to bioavailability.
While bioavailability varies, plant-based diets and supplementations are generally seen as relatively low-risk ways to make meaningful improvements in overall health and wellbeing. We were made to consume whole foods and nutrients from nature.
5. The bioavailability of some nutrients is fairly well-understood.
You may have heard that some vitamins and minerals are nutritional BFFs, such as Vitamin D and Calcium, or Iron and Vitamin C. Meanwhile, Vitamin E can reduce intake of Vitamin K. These pairings to be made or avoided are well-known and fairly well-understood by nutritionists.
6. The bioavailability of other nutrients is less clear.
The components in food are so complex that they are often said to be a “matrix” of nutrients. Sometimes even when we know a basic fact -- such as "Vitamin A hampers Vitamin D absorption" -- the actual mechanisms for how this works (or, in this case, how absorption does not work) are still unclear. Scientists are still researching many facets of the overall uptake and absorption of food in humans.
7. How many nutrients we absorb are influenced by our states of being and our genes.
As indicated above, your age, overall health, and family history greatly influence how bioavailable certain foods or nutrients are to you. Disease and degeneration hinder the absorption process. This is one of many reasons why preventive actions are so important in overall health care. You want to keep your cells, and your entire body, healthy and happy for as long as possible.
8. Vitamin requirements need to be evaluated alongside other nutrients and compounds in the body.
You can’t really consider a vitamin or supplement independently. You have to look at what else is going on. That’s how biology works--through symbiotic relationships. And it harkens back to that saying of Dr. Dyer’s that “what you eat controls what you eat.” Your nutritional choices have both immediate and cumulative results.
9. Once you eat or drink something, that doesn’t mean you absorb all the nutrients.
Obviously, when you think about the processes listed above, you can see that just eating or drinking a nutrient may not translate into that nutrient being absorbed by your cells. Of all the nutrients you consume, only some can make it through your digestive tract, into your bloodstream, and then onto your cells.
10. More research on the bioavailability of micronutrients would be welcomed.
Studies of bioavailability of nutrients in humans is still rather limited. Some studies have even described the current body of literature as “a paucity of research.” We hope this changes in the near future.
So, as you can see, bioavailability is a fascinating topic that presents even more fascinating questions. We look forward to continuing to learn about the relationship between what we ingest and what we retain as more studies develop.
Meanwhile, we’ll continue to pursue optimal health by providing you with supplements for common gaps. Our products were developed to address nutritional deficiencies we’ve seen in our work as health care providers over the years.
Almeda’s supplements (such as Kasvi and Encarna) always blend concentrates of nutrient-dense foods to help maximize absorption, as possible. We also recommend you eat whole foods along with these supplements at every opportunity… but have some fun with it. Continue to check out our recipes for fresh food and drink ideas on the reg.