Login

Influences on the Absorption, Retention, & Availability of Minerals in the Body

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Minerals in Our Food: Functions in the Body & Food Sources

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
 Replay
Your next lesson will play in 10 seconds
  • 0:01 Bioavailability
  • 1:16 Phytates, Oxalates & Tannins
  • 2:58 Other Minerals
  • 3:40 The Body's Needs
  • 4:12 Mineral Loss
  • 4:39 Lesson Summary
Add to Add to Add to

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Login or Sign up

Timeline
Autoplay
Autoplay
Create an account to start this course today
Try it free for 5 days!
Create An Account

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Rebecca Gillaspy

Dr. Gillaspy has taught health science at University of Phoenix and Ashford University and has a degree from Palmer College of Chiropractic.

Minerals are inorganic compounds needed by your body. The degree to which minerals can be absorbed, retained and made available depends on factors such as different components of your diet and your body's need for the mineral.

Bioavailability

I'm sure you've noticed that your paycheck doesn't include all the money you earned. You might have earned $500, but because some of that money was removed for taxes, you only ended up with $450 available to spend. Something similar happens with minerals, which are inorganic compounds needed by your body to regulate chemical reactions and maintain structures; you might take in 100% of the recommended dietary allowance for a mineral, such as calcium, but because of factors that interfere with its absorption and retention, you might only get to use 25% of it.

So even if the minerals you need make it from your dinner plate into your body, you're not assured that all those minerals are available for use. This is referred to as bioavailability, or the degree to which a nutrient can be absorbed, retained and used by the body. It helps to remember that the prefix 'bio' refers to life. So, the bioavailability of a mineral is literally the amount that is available to carry out life processes. In this lesson, we will take a look at factors that influence the absorption, retention and, therefore, the availability of minerals from the foods you eat.

Phytates, Oxalates & Tannins

We get minerals from both animal products and plant-based foods. As a general rule, minerals obtained from animal products are more readily absorbed than those from plants. This is due to the fact that compounds found in plant foods can interfere with mineral absorption. These include phytates, which are compounds found in whole grains and other plant foods that can bind to calcium, iron, zinc and other minerals and interfere with their absorption. It's almost as if phytates fight against the body's desire to absorb minerals.

Other compounds found in plants that interfere with mineral absorption include oxalates, which are compounds found in plant foods that bind to calcium and interfere with its absorption. Oxalates are found in vegetables, especially spinach, beets and rhubarb. They're also present in other plant-based foods, like nuts and even chocolate. When you consume oxalates, they can combine with calcium to form calcium oxalate. This compound not only keeps the calcium from being absorbed, it also must be flushed through your kidneys. If the level of calcium oxalate gets too high, it results in crystal formations in your kidneys, leading to kidney stones.

There is another dietary factor that interferes with the bioavailability of certain minerals, namely tannins. Tannins are compounds found in tea and certain grains that interfere with iron absorption. It might help you to recall this relationship between tannins and iron if you remember that tannins are what give most teas their rusty tan or brown color, and when iron rusts it turns rusty brown.

Other Minerals

Bioavailability can also depend on the combination of minerals you consume due to the fact that certain minerals can interfere with the absorption of other minerals. For example, different mineral ions can carry the same charge. We see this with calcium, iron and zinc, which all carry a 2+ charge. Mineral ions with similar charges compete for absorption out of your digestive system. This is not usually a problem if the minerals are coming from foods, but can be a factor if you're taking a mineral supplement that is high in one mineral. In essence, the mineral that is taken in excess hogs up all the available absorption, leaving no room for the other minerals.

The Body's Needs

Your body is always interested in maintaining balance, so it rarely holds on to more than it needs. Because of this, we see that your body's needs influence the absorption of minerals. For example, your body can store iron. If enough iron is in storage, then your body will absorb less from the foods you eat. Likewise, if your body is in need of more minerals, absorption can be increased. For example, a pregnant woman requires more calcium, so her body will absorb more to meet the growing need.

To unlock this lesson you must be a Study.com Member.
Create your account

Register for a free trial

Are you a student or a teacher?
I am a teacher
What is your educational goal?
 Back

Unlock Your Education

See for yourself why 10 million people use Study.com

Become a Study.com member and start learning now.
Become a Member  Back

Earning College Credit

Did you know… We have over 95 college courses that prepare you to earn credit by exam that is accepted by over 2,000 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it free for 5 days!
Create An Account
Support