March 18, 2023 4 min read

Cheat Sheet: The Most Bioavailable Forms Of Vitamins and Minerals To Look For in Supplements

Cheat Sheet: The Most Bioavailable Forms Of Vitamins and Minerals To Look For in Supplements


When it comes to taking vitamin and mineral supplements, there are a lot of factors to consider. From the dosage amounts to the quality of ingredients, knowing how to decipher the best daily supplements can make all the difference in how well they work. 

In our  last blog post, we did a deep dive into everything you need to know about reading supplement labels and what to look for, and look out for. Today, we’re going to focus on why the exact form of each ingredient matters for bioavailability and results.

What is Bioavailability?

Bioavailability is the extent to which nutrients can be absorbed and utilized by the body.

Bioavailability is a crucial factor to be aware of.  Focusing on bioavailable ingredients ensures that you get the best results from your supplementation. 

MTHFR Gene Mutation

For those with the MTHFR gene mutation (40% of the population!) it is even more important to select vitamins and minerals that are highly bioavailable. 

The MTHFR gene mutation is an inherited genetic disorder that affects the body’s ability to convert (or methylate) folate, or vitamin B9. 

It is caused by a defect in an enzyme known as methylenetetrahydrofolate reductase (MTHFR). This enzyme plays a key role in converting folate from food into its active form, which is used by the body for various metabolic processes. 

Those with the MTHFR gene mutation have difficulty processing folate efficiently, leading to a range of health issues such as increased risk of stroke, neurological problems, birth defects, depression, anxiety, migraines, and infertility. Not small stuff.

Because of this reduced absorption rate of vitamins and minerals from food sources, it is important for those with this condition to look for forms of vitamin and mineral supplements that are already methylated or highly bioavailable.


One form that works well for those with the MTHFR gene mutation is methylated vitamins, which have been modified in such a way as to reduce or eliminate their allergenic properties. Methylation also improves the absorption rate of these vitamins in the body, making them easier to absorb and use more efficiently than other forms of vitamins. 

Two primary examples of methylated vitamins include Folate as L-Methylfolate or 5-MTHF,  and Vitamin B12  as Methylcobalamin. 


Another term that you’ll often see within the subject matter of bioavailability is “chelation” or “chelated ingredients” (pronounced “key-late-ed).  Chelation is a process where a mineral is bound to an amino acid or protein molecule, which helps the body absorb and use the mineral more efficiently. 

Examples of chelated minerals include Magnesium as Glycinate, Calcium as Citrate, and Zinc as Zinc Chelate.

You can view the above examples on the Abundant Earth Labs Whole Food Multivitamin Supplement Facts panel   here for reference.


Examples of Our Favorite, Bioavailable Vitamins and Minerals

Below is a list of ten of the most commonly used vitamins and minerals and examples of bioavailable forms that you should look for when purchasing a supplement.  

This list isn’t exhaustive, but these are some of our favorite forms.  With a plethora of cheaper, less bioavailable options available on shelves everywhere, information is power.  On to our favorites:

  • Vitamin D: Vitamin D3 as Cholecalciferol
  • Vitamin C: while we prefer to use whole food sources like Amla Fruit or Acerola Cherry instead of synthetic ascorbic acid, the studies do show identical bioavailability rates between the two, so this is up to personal preference
  • Vitamin B9: as L-Methylfolate and not synthetic Folic Acid
  • Vitamin B12: as Methylcobalamin or Adenosylcobalamin and not Cyanocobalamin 
  • Iron: as Ferrous Bisglycinate Chelate 
  • Magnesium: as Magnesium Glycinate or Bisglycinate (the same thing),  Magnesium L-threonate, Magnesium Malate, and Magnesium Citrate (this form can cause laxative effects if too much is taken so do take care)
  • Zinc: as Zinc Chelate 
  • Calcium: as Calcium citrate
  • Selenium: as L-selenomethionine 
  • Vitamin E: Natural Vitamin E as  d-alpha-tocopherol is more bioavailable than synthetic vitamin E as  dl-alpha-tocopherol.  (On a supplement label, synthetic forms of vitamin E are labeled with a dl- prefix  so you have to watch out that you choose d-alpha and not dl-alpha).


What Else Can Influence Bioavailability?

It is important to note that the bioavailability of a nutrient can also be influenced by other factors such as the presence of other nutrients in the supplement.  For example, calcium and iron shouldn’t be taken together at the same time, even if they are both in bioavailable forms, as calcium prevents full iron absorption.  

An individual's unique digestive health and diet can also influence bioavailability, so it is always recommended to consult with a healthcare professional before starting any new supplement regimen.



When selecting a vitamin or mineral supplement, it’s important to look for highly bioavailable forms which can include chelated and methylated forms, which have been shown to be better absorbed by the body than other forms. 

We hope this also helps to explain the ingredient choices that went into the excellent formulation of our  Whole Food Multivitamins and why so many Abundant Earth customers experience results they can actually feel. As always, doing research on what type of form is right for your specific health needs will ensure you get the most out of your supplementation routine!