Vitamins and Minerals that Affect Absorption

The Human Body is a complex piece of equipment.

For example, if you take a 500mg Vitamin C pill, is the entire 500m absorbed into your body?  Are you sure?

Are you sure that 500mg is still 500mg after you open it, with air trapped in the bottle, and shaking the bottle up and down a few times?  Are you sure it will be 100% absorbed?  

There are a lot of factors that determine there absorption of Vitamin and Minerals.. it’s not simple math, because every body is different.

Let’s take a look a few important ones.



There’s a reason why Vitamin D is fortified in milk… to help calcium absorption!  (In the old days, it was marketed to help prevent rickets. If you don’t know what rickets are, Google it :)  In fact, both Vitamin A & D helps increase calcium absorption.  

Conversely, Magnesium decreases calcium absorption.


Read Nick’s article on Magnesium last week.

Magnesium’s absorption can be increased by Vitamin D, and absorption can be decreased by Calcium and Sodium

By now, I have confused you, and that is my point :)  Because there are a few “vicious circles”.


Many women take iron supplementation, and of course, too much of it caused constipation.

Generally, iron absorption is increased by Vitamin C.

However, iron absorption is decreased by:

  • Calcium
  • Magnesium
  • Zinc
  • Copper
  • Chromium
  • Manganese


I swear by zinc, and that is why I took ZMA in the past.

The new ZMA formulation is called ZMA-5 with two new ingredients, 5-Hydroxytryptophan (known as 5-HTP) and Folic Acid (also know as Vitamin B9).  This is one of the few supplements I take, along with Vitamin D.

Zinc absorption is increased by amino acids, which is why ZMA has B6 as the only one of three ingredients!

However, zinc absorption is decreased by:

  • Calcium
  • Iron
  • Manganese
  • Selenium
  • Copper


One of the most important regulators in cellular balance is sodium and potassium levels, especially during hot weather with heavy sweating and fluid loss. 

Sodium absorption increased by Amino Acids, however, both sodium and potassium absorption is decreased by Calcium & Magnesium

As you can see, it’s not an easy matrix to figure out.

So what to do?

  1. Eat whole natural foods for most (if not all) of your essential vitamins
  2. Talk to your mother
  3. See #1 and #2

Regular Blood Testing

If you want to be 100% sure about your possible deficiencies, then I recommend you get regular blood tests and monitor the changes.  I used InsideTracker in the past (read my story here – with shocking values), and now they offer remote blood testing using drops of blood that can be mailed internationally.


  1. Kutsky, R.J., Handbook of Vitamins, Minerals and Hormones 
  2. Underwood, E.J., Trace Elements in Human and Animal Nutrition

Jimson Lee

Jimson Lee

Coach & Founder at
I am a Masters Athlete and Coach currently based in London UK. My other projects include the Bud Winter Foundation, writer for the IAAF New Studies in Athletics Journal (NSA) and a member of the Track & Field Writers of America.
Jimson Lee
Jimson Lee
Jimson Lee

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