Cofactors for Vitamin D

One of the most overlooked parts to beginning a Vitamin D regimen is its cofactors.  Without adequate amounts of the cofactors, you won’t absorb the full amount of the vitamin, and it can put you at risk for a calcium imbalance.


    Your body needs Magnesium to activate Vitamin D in the bloodstream.  It is one of the number one reasons why supplementing with Vitamin D sometimes fails to raise the blood levels as expected.  When your body is using magnesium to activate Vitamin D, it can cause already low magnesium to be pushed into a deficiency.  (This is one reason why a good doctor will test for a magnesium deficiency after Vitamin D supplementation has increased your Vitamin D levels).

    Most people already have low levels of magnesium due to the depletion of the mineral in our soils, and the low consumption of foods that contain magnesium, such as whole grains, leafy green vegetables, nuts, and chocolate.

    Magnesium can also help with some of the side effects that can be experienced when you start    Vitamin D supplementation therapy.  One of the side effects is a rapid heartbeat or feelings of uneasiness. Due to magnesium’s relaxing properties, it can mitigate some of these side effects.  This is ultimately one reason why people will take Vitamin D, get their levels higher, and then feel “off” and decide to stop taking their supplements.  If you are taking Vitamin D, do yourself a favor and take Magnesium with it for superior absorption and to prevent a deficiency.

    Vitamin K2

      Vitamin K2 is different than what we commonly call “Vitamin K” which refers to Vitamin K1.  Vitamin K1 is the K we think of when we see leafy green vegetables (like kale and spinach).

      Vitamin K2 is found in high amounts in dairy (butters, cheeses, milks), liver, egg yolks, and the dark meat of chicken.  K2 is even higher in grass-fed varieties, but the highest amount of K2 you can find is in a Japanese dish called “natto” which is fermented soybeans.

      When we, or any animals, eat K1 from our leafy greens, we convert it into K2.  This is why grass-fed animals who have consumed K1 have higher levels of K2 in their milks and meat.

      The two types of Vitamin K2 are MK-4 and MK-7.  Animal-derived sources contain MK-4, and MK-7 is found in fermented vegetables.  Any of these forms are a cofactor for Vitamin D.

      You need to ingest adequate Vitamin K while on Vitamin D supplements because Vitamin K and D work synergistically to make sure that the calcium you eat goes to your bones, rather than to your arteries.

      *Please talk to your doctor if you are taking any blood thinning medications like Coumadin or Wafarin because Vitamin K can affect your blood clotting*


        Zinc enhances Vitamin D’s ability to work inside your cells and is also important to make sure the calcium you ingest gets to your bones and does not go to the circulatory system.  Zinc also helps Vitamin D in bone development and keeps them strong.

         Vitamin A

          Vitamin A comes in two forms:  beta-carotene and retinol.  Beta-carotene is found in bright orange fruits (carrots, mango, apricot) and leafy greens, while retinol is found in organ meats, butter, cheese, and milk.

          Vitamin A and Vitamin D work with each other to make sure that Vitamin D works with your cells for genetic functions.  It is easy to take too much Vitamin A in a supplement form and it can interact with medications, so it’s best to consult with your doctor before you start Vitamin A supplements.  The Vitamin D Council feels that if you strive to incorporate these types of Vitamin A-rich foods, you will be consuming enough through your diet alone to enhance your Vitamin D supplements.


             Lastly, boron is a trace mineral that helps Vitamin D in bone development and to keep your bones healthy.  Boron is found in fruits, nuts, leafy vegetables, avocados, peanut butter, and raisins.

            There is currently no RDA for boron, but there is an upper intake level (which tells you how much the maximum amount is).


            Incorporating these cofactors can really make the difference in how well your Vitamin D supplements work for you.  Some companies sell Vitamin D “absorption packs” which have all the cofactors in a supplement form so you can take them altogether with Vitamin D, and some companies have started adding in Vitamin K2 to their Vitamin D formulas.

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