Getting the Balance Right – Vitamin D Co-Factors

When supplementing vitamin D, it is important to make sure you are getting the right amount of calcium and magnesium. Also zinc, boron, vitamin A and vitamin K2. These nutrients work together with vitamin D. Without them, vitamin D will not be as effective, and may even make you feel sick.

Getting the Balance Right - Vitamin D Co-FactorsIf you eat a healthy diet, then you are off to a good start. A healthy diet is rich in organic plant foods, vegetables, fruit, whole-grains, seeds and nuts, as well as fish, poultry and a little dairy. Such a diet will probably meet your needs for all your vitamin D co-factors.

But for those of us with less-than-ideal diets, supplements are pretty much essential. So here are the nutrients that work together with vitamin D. Note that all doses on this page are adult doses.


Your calcium intake can actually be reduced as your vitamin D levels rise, because the higher your vitamin D level rises, the more calcium you will absorb.

When you are vitamin D deficient you may only absorb around 20% of your calcium intake, but when your vitamin D status improves to optimum, you can absorb as much as 50% of the calcium in the foods (and supplements) you eat.

Form of CalciumThe form of calcium supplement you take also affects absorption, because some calcium compounds are more readily absorbed than others. These are the compounds commonly found in calcium supplements (best on top)

  • Orotate
  • Malate
  • Gluconate
  • Citrate
  • Phosphate
  • Carbonate

Most people with optimum vitamin D levels and reasonable diets get enough calcium from food alone. So if your vitamin D levels are optimum, you may not need to worry about supplementing calcium. In fact it might be better if you don’t. According to the Mayo clinic, excessive calcium may increase your risk for

  • Kidney stones
  • Prostate cancer
  • Constipation
  • Calcium build-up in your blood vessels
  • Impaired absorption of iron and zinc

If you eat a good diet, reduce your calcium supplementation while increasing your vitamin D levels, and when you reach optimum vitamin D, stop taking calcium supplements altogether.

If your diet is not good you should continue supplementing calcium, but we recommend you gradually reduce your daily calcium supplementation as your vitamin D levels increase, so that when you reach optimum vitamin D (50-65 ng/ml) you are taking no more than 400 mg of elemental calcium.

Calcium supplements are available online from Amazon or iHerb.


Unlike calcium, our need for magnesium increases with higher levels of vitamin D. Magnesium cooperates with vitamin D in many useful tasks. In fact, magnesium is even required to make the enzymes that metabolize vitamin D.

So the higher your level of vitamin D, the more magnesium you need.

Most of our over-cultivated soils are already short of magnesium. And more magnesium is lost in food processing. So about half the population in US is deficient in magnesium.

If you are short of magnesium and you increase your vitamin D intake, your magnesium will be used up even faster, and you may even start to notice symptoms of magnesium deficiency.

Here are some common magnesium deficiency symptoms

  • Cardiac arryhthmia
  • Depression
  • Fibromyalgia
  • Muscle cramps
  • Increased blood pressure
  • Migraine headaches
  • PMS
  • Restless legs

There are more. Magnesium does over 300 different jobs in your body.

Strong bones need magnesium too!Another reason for taking more magnesium: bones don’t just need calcium – they need magnesium too. Over 60% of the magnesium in your body is actually found in your bones.

Even getting calcium into your bones requires magnesium. Without magnesium, calcium can’t be built into your bones.

But it can be deposited in all the wrong places – like your heart, arteries and kidneys.

Magnesium helps prevent this from happening.

We recommend you supplement 300 – 500 mg of elemental magnesium daily. (Or eat lots of whole grains, seeds, nuts and beans!) If you take a multivitamin or a bone supplement, there will be some magnesium in those already, but probably not enough.

You can purchase magnesium supplements online from Amazon or iHerb.

One last point about magnesium – it acts as a laxative at higher doses, especially if your body is not used to so much. So split your daily magnesium supplement into two or even three doses (with meals) and you’ll be fine.

Vitamin D and Vitamin A

Vitamin D requires a small amount of vitamin A (retinol) in order to function. But vitamin A and vitamin D attach themselves to the same cell receptors. If you have too much vitamin A, it grabs those cell receptors and leaves no room for vitamin D.

So even though you might take enough vitamin D, it can’t work properly if you also have too much vitamin A (retinol).

We recommend supplementing no more than 2000 IU of retinol daily. But make up for it with extra beta-carotene.

Beta carotene - Eat as much as you want!Beta-carotene is a vitamin A precursor found in some green, yellow and orange vegetables.

You can take in as much beta-carotene as you please if you obtain it from vegetables.

If you don’t eat enough vegetables, take a beta-carotene supplement, about 5000 IU (3 mg) daily. Beta carotene is available online from Amazon or iHerb.  (You should also find some beta-carotene in a good multivitamin).

Your body will get all the vitamin A it needs by converting beta-carotene to retinol. This process is regulated, so your body will never create more retinol than it requires, and not enough to get in the way of your vitamin D.

Vitamin D and Vitamin K2

Optimum vitamin D means that you will have a lot of calcium available for your body to use, so it is very important that it be deposited in the right place (in your bones) and not in your arteries where it forms arteriosclerotic plaques leading to heart disease.

That’s where vitamin K2 comes in. Its job is to ensure that calcification occurs in your bone, and not in your arteries.

Even with low levels of  vitamin D, calcium is constantly present in the bloodstream because it is needed by the heart, nervous system, muscles and for many other vital functions. It is so important that the body always ensures  the right amount of calcium is present wherever it is needed.

It’s too important to rely on calcium being absorbed from the diet. So it raids the bones and takes a small amount of their calcium every day.

When all co-factors are present in the right quantities, this calcium will be returned to the bones when no longer required. But if one co-factor is missing, the body will not be able to restore its calcium to the bones. Then it has to deposit the calcium in the arteries and soft tissues instead.

Brie cheese for Vitamin K2If you are eating a good diet with lots of green leafy vegetables, then you will be getting plenty of vitamin K1. And if your bowel has plenty of the right beneficial bacteria, they will make vitamin K2 for you from the vitamin K1 you take in.

Other sources of vitamin K2 are certain types of soft cheese, mainly brie and gouda, and a traditional Japanese food known as natto – made from fermented vegetables.

If your diet does not contain much of these foods, then you need to supplement vitamin K2 (preferably in the MK7 form) between 40 – 100 mcg daily (adults). Get them online if you wish, from Amazon or iHerb.

Here’s a cool thing. Not only can vitamin K2 help prevent you from depositing calcium in your arteries, it can also REMOVE calcium deposits already in your arteries! A bit like a bottle-brush.

 Boron and Zinc

Last but not least, two other essential minerals are needed in order for vitamin D to do its work in the cells of your body, boron and zinc. People are commonly deficient in these minerals, so it is good to supplement them.

Both zinc and boron are also involved in creating bones, so that is another good reason to make sure you are getting enough.

White spots on the fingernails, not caused by injury, can be a sign of zinc deficiency.

Nuts are rich in mineralsFor zinc, supplement 15 – 20 mg per day. For boron, you only need 3 – 6 mg daily.

By the way, did I mention that if you eat nuts, whole grains, seeds and beans, you are probably getting enough zinc and boron already?

That’s why you never see a squirrel with white spots on its fingernails!

Anyhow, zinc supplements are available online, from Amazon or iHerb.

For boron, you can get a single-element boron supplement or a bone formula containing calcium, magnesium and boron at iHerb or Amazon.