Vitamin D Deficiency and Why You Should Never Supplement With Vitamin D3

Have you been told you have a vitamin D deficiency?

If so, you'll want to read this article because what you've been told may not actually be the truth. In this article we'll cover:

  • Why your doctor / health care practitioner may truly believe you have a vitamin D deficiency even though that may not be correct
  • Why testing for vitamin D deficiency is often inadequate and incomplete
  • Why, even if you have been supplementing with vitamin D, your vitamin D levels remain low
  • Why you may have noticed more problems in your health after long-term vitamin D supplementation
  • How to accurately assess your vitamin D status
  • What factors impact your vitamin D levels
  • How recent research has debunked the most common myths around getting enough vitamin D
  • What low vitamin D levels really mean
  • What factors are actually more important in creating health than vitamin D
  • A strategy for figuring this all out, determining how it impacts you personally and putting together a customized action plan

If you're wondering how this vitamin D "craze" got started in the first place, this article, does a good job at "setting the scene" for what we're about to cover.

So let's start by looking at vitamin D deficiency within the context of current affairs...

COVID-19 and Vitamin D Deficiency

The first randomized, controlled trial on vitamin D and COVID-19 was published on August 29, 2020. You can read the full text of the study here, but here's a brief summary:

  • 76 patients diagnosed with COVID-19 pneumonia were randomized into two groups: 50 received vitamin D supplementation, 26 did not.
  • The dose of vitamin D3 given was 30,000 IU per day for the initial week, then 7,600 IU per day until discharge, ICU admission or death.
  • In the control group (the group not taking vitamin D), 50% required ICU admission.
  • In the vitamin D group, 2% were admitted to the ICU.
  • In the control group there were two deaths.
  • In the vitamin D group there were zero deaths.

The findings for ICU admission were deemed significant; however the findings for the deaths were not statistically significant (the number of deaths was too small).

What do the findings tell us?

The researchers of the study concluded that "administration of high dose calcidiol (25-hydroxyvitamin D) significantly reduced the need for ICU treatment of patients requiring hospitalization due to proven COVID-19."

From that conclusion many will believe this suggests the need for vitamin D treatment... supplementing with vitamin D3 if your levels are low and using higher doses if you contract COVID-19.

There is even a campaign called #StopCOVIDCold that emerged to raise awareness of the importance of vitamin D in protecting against (and treating) COVID-19.

That's the common belief, anyway: a blood test shows vitamin D deficiency so we need to supplement with vitamin D to raise those levels.

Problems with the conventional approach

There are problems with the conventional approach, however.

First, the standard vitamin D test checks what is called 25-hydroxy vitamin D. This is not active vitamin D. It's the storage form that circulates in your blood until more vitamin D is needed.

When more vitamin D is needed, this precursor - the 25-hydroxy version - is converted into 1,25(OH)2D, the active form.

What's commonly found when both forms of vitamin D are tested is that the precursor is low while the active form is almost always normal or quite often high.

Why does this happen?

The short answer is because of "bad bugs." Bacterial toxins clog up the vitamin D receptors (VDR). The clogged receptors tell the body that vitamin D is low and the body converts the precursor into the active form too fast.

That's why the precursor - the form measured on most tests (including in the study mentioned above) is now low while the active form (typically not measured) is high.

So why do people feel better after taking high doses of vitamin D then?

Good question!

When high doses of vitamin D are taken it's like turning the immune system's "control knob" down to low. You're essentially suppressing the immune system.

That's also why people with autoimmune conditions often feel better taking higher doses of vitamin D (at least in the short term).

People with Lyme disease will often feel better while taking high doses of vitamin D because the vitamin D reduces the immune system's capacity to kill off the bacteria. Less "die-off" means less symptoms.

Why Vitamin D Is Low

The real reason why vitamin D is low is because of inflammation and toxins produced by bacterial infections.

The inflammation causes the body to convert the inactive precursor into the active form of vitamin D more quickly than normal.

The result?

Your 25-hydroxy vitamin D test comes back low. But your active vitamin D will be normal or even high. Sometimes it can be dangerously high (I'll explain the consequences of that shortly).

Unfortunately, your doctor may not know the difference between the two forms and you may be receiving incorrect / insufficient testing.

Dr. Trevor Marshall, professor at Australia's Murdoch University School of Biological Medicine and Biotechnology, is a leader in researching vitamin D and its actions in the body. He writes:

"Molecular biology is now forcing us to re-think the idea that a low measured value of vitamin D means we simply must add more to our diet. Supplemental vitamin D has been used for decades, and yet the epidemics of chronic disease, such as heart disease and obesity, are just getting worse.
Our disease model has shown us why low levels of vitamin D are observed in association with major and chronic illness. Vitamin D is a secosteroid hormone, and the body regulates the production of all it needs. In fact, the use of supplements can be harmful, because they suppress the immune system so that the body cannot fight disease and infection effectively."

Low vitamin D is the result of the disease process - not the cause of disease.

Vitamin D deficiency is the result of the disease process, not the cause of disease.

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Click here for an extensive reference list of Dr. Marshall's research publications.

Vitamin D supplementation does not address inflammation

vitamin d deficiency

Mangin, M., et al. (2014). “Inflammation and vitamin D: the infection connection”

What can be most confusing to patients and doctors is that supplementing with vitamin D will not correct the inflammatory or disease process. The above diagram does a good job at illustrating this point.

It also points to the need to test 1,25(OH)2D - the active form - in addition to the 25(OH)D - inactive form.

Elevated levels of 1,25-D exist at the site of disease and are simply an indication that the innate immune system is responding to an infection.

Remember, our bodies are wise and innately intelligent. It makes sense that it would respond to an infection in this manner.

vitamin d supplementation

Vitamin D: the alternative hypothesis (

I'll assume you can appreciate the fact that the absence of disease symptoms is not the same as the absence of disease. The graph above, taken from one of Dr. Marshall's papers, illustrates this fact in respect to vitamin D supplementation.

It's analogous to the use of corticosteroids, which often reduce symptoms of cardiovascular and autoimmune conditions in the short-term, but can worsen the disease process over time. And these adverse effects often take decades to be experienced.

The disease process continues, it just may take longer to be felt. And supplementation may actually make the disease process worse.

In my opinion, that's the opposite of taking a pro-active, root cause approach to creating health.

Two important minerals come into play

When answering the question why is vitamin D low we also need to consider two important minerals: magnesium and iron.

Let's start with magnesium...

magnesium and vitamin D

Deng, X., et al. (2013). “Magnesium, vitamin D status and mortality: results from US National Health and Nutrition Examination Survey (NHANES) 2001 t0 2006 and NHANES III.”

All the red circles in the above diagram are magnesium - those are all the steps that it takes to get to the active form of vitamin D that are dependent upon adequate magnesium levels.

Magnesium deficiency impacts vitamin D status.

iron and vitamin d

Ezzat, H.M., et al. (2015). “Vitamin D Deficiency and Liver Iron Concentration Transfusion Dependent Hemoglobinopathies in British Columbia”

Several studies have shown an inverse relationship between iron and vitamin D - that as iron levels rise, vitamin D levels drop.

The above diagram shows a key liver enzyme called AST, representative of liver function, being impacted by iron levels.

Iron gets in the way of the conversion of vitamin D in the liver.

So not only does magnesium deficiency impact vitamin D status, excess iron does, too.

Now let's connect this back to inflammation...

Serum ferritin (a marker for how much iron is being stored in your body's tissues) is a marker of inflammation.

High Ferritin (stored iron) = Inflammation

And we know from research that low magnesium is a factor that triggers the inflammation cascade.

Low levels of storage or inactive vitamin D are a sign of low magnesium and excess, unbound iron. So low vitamin D isn't what needs to be corrected, it's the ratio of the other minerals - magnesium and iron - that needs to be corrected.

Vitamin D Side Effects

We've covered a few vitamin D side effects already. Here's a summary of why you should never supplement with synthetic vitamin D even if you are told you have a vitamin d deficiency...

  1. Supplementation with vitamin D temporarily palliates symptoms of chronic disease, but leads to higher morbidity in the long-term as it allows pathogens to proliferate over time.
  2. 25-hydroxy vitamin D suppresses our immune system.
  3. Vitamin D supplementation may deplete our cells of potassium, making us more vulnerable to high iron levels.
  4. Vitamin D supplementation can cause ATP depletion, which is how our cells produce energy.
  5. Vitamin D supplementation can destroy vitamin A reserves.
  6. Vitamin D supplementation confuses our understanding of the need for sunlight exposure - its unique benefits - and tricks us into thinking "we're safe" or that we're "optimizing our health."

Above all of this, there is no evidence that vitamin D supplementation provides any benefit or reduces risk or mortality of any disease.

Vitamin D supplements are synthetic and toxic. They are soy-based, not sun-based.

They are certainly not a panacea for optimizing your health as you have been led to believe.

In fact, hopefully the above information has led you to question not only vitamin D's lack of evidence, but also it's detriment to our health - actually weakening our metabolic pathways and immune function.

Think critically the next time another study or article or "expert" purports the benefits of vitamin D.

Ask yourself, "Do flies cause garbage?"

No, of course not.

The same goes for vitamin D.

Vitamin D deficiency is correlated with many conditions because it's a reflection of the terrain or state of the internal environment (i.e. inflammation, pathogens, toxins). 

Vitamin D deficiency is not the cause. It makes no logical sense to supplement as a means of correcting the root causes that led to disease in the first place.

It's difficult to ingest too much vitamin D from food and natural mechanisms prevent excessive amounts of vitamin D3 being photosynthesized from sunlight. So it's highly unlikely to achieve excess vitamin D from those natural sources. 

De-bunking The Myths Around Vitamin D Deficiency

Proponents of vitamin D supplementation, in general, provide the following arguments why the general population cannot obtain enough vitamin D without supplementation:

  1. Living in the Northern hemisphere we're exposed to less sun.
  2. Our clothes block sun exposure.
  3. We need to use sunscreen.
  4. Air pollution blocks sun exposure.
  5. The nature of urban environments prevents adequate sun exposure.
  6. Cloud cover blocks sunshine.
  7. Our diets don't contain enough vitamin D.

Let's look at each of these in turn...

Do Northern latitudes provide insufficient sunlight?

Recent studies disprove this hypothesis:

"It may no longer be correct to assume that vitamin D levels in populations follow latitude gradients." - Kimlin et al.

"Geophysical surveys have shown that UV-B penetration over 24 hours, during the summer months at Canadian north latitudes when there are many hours of sunlight, equals or exceeds UV-B penetration at the equator." - Lubin et al.

"Ample opportunities exist to form vitamin D (and store it in the liver and fat) from exposure to sunlight during the spring, summer, and fall months even in the far north latitudes." - Ross et al.

Do clothes block UV rays?

Clothing is a barrier, however this is only an issue for people who cover themselves from head to toe. It takes relatively little sunlight exposure to acquire adequate stores of vitamin D and few people wear enough clothes to prevent that from happening.

"Ten to fifteen minutes of sunlight or daylight exposure to a small area of skin (for example, the forearm or face) twice a week (without sunscreen) supplies all the vitamin D necessary for health." - NIH

Does sunscreen use prevent photosynthesis?

"Far more lives are lost to diseases caused by lack of sunlight than by those caused by too much." - Lucas et al.

"Emerging evidence suggests that although sunscreens are effective, many may not actually be blocking UV-B because they are improperly or inadequately applied. Thus, sunscreen use many not actually diminish vitamin D synthesis in real world use." - Diehl et al.

Does pollution block UV rays?

Although pollution can block some UV radiation, even in urban areas of high pollution, 50% of UV rays reach the ground.

"Reductions in atmospheric ozone, due to pollution, are expected to result in higher amounts of UV-B radiation reaching the earth's surface." - Madronich et al.

Do tall buildings and clouds block UV rays?

Tall buildings provide shade, but shade gives up to 50% of UV rays. UV radiation is reflected or scattered to varying degrees by different surfaces.

For example, fresh snow can reflect up to 80% of UV radiation. 90% of UV rays penetrate clouds.

Are modern diets deficient in vitamin D?

Food commonly consumed in a western diet, for example 3 cups of milk, 1 serving of fortified cereal, 1 cup of fortified juice and 3 ounces of cheese, supply 600 IU of vitamin D.

Eggs, fatty fish, cheese all contain natural sources of vitamin D. So it's reasonable and possible to achieve the recommended daily amount of 600 IU from food.

See vitamin D rich foods below for more detail.

But, I've been told that vitamin D is beneficial for X condition...

Let's look at two of the most common conditions where vitamin D supplementation is prescribed: osteoporosis and autoimmune disease.

Osteoporosis is a bone disease where there's a decrease in bone mineral density and the appearance of small holes in bones due to loss of minerals.

The active form of vitamin D - 1,25(OH)2D - helps regulate calcium balance between blood, cells and bones by stimulating calcium absorption from the intestines, re-absorption in the kidneys and resorption in bones.

The problem comes in if 1,25(OH)2D is elevated. When levels are above 42 pg/ml it stimulates bone to breakdown.

"A combination of high 1,25(OH)D and low 25-D is associated with the poorest bone health." (PMID: 23386642)

"We found no evidence that calcium and vitamin D supplementation reduces the risk of clinical fractures in women with one or more risk factors for hip fracture." (PMID: 15860827)

This points again to the need to measure both 25(OH)D and 1,25(OH)2D forms of vitamin D.

The common theory behind autoimmune disease is that an overactive immune system produces antibodies against self - ie your body "attacks itself." What could actually be happening is a chronic, stealth infection.

When our innate immune system - our first line of defense - is forced to respond to a persistent infection, it triggers a cascade of cytokines and chemokines (proteins produced by our cells) that stimulates our adaptive immune response - that part of our system responsible for getting rid of the "foreign invader."

Vitamin D seems to have a positive effect because it suppresses that immune response. As a result of reducing this inflammation brought about by our immune response, disease markers and symptoms will reduce.

However, vitamin D does not treat the underlying cause. And that's why relapse is common.

Think about it this way...

Why has chronic disease increased even though vitamin D supplementation has increased?

More foods than ever are fortified with vitamin D (dairy, breads, pasta, juices). Sales of vitamin D supplements are big business.

Vitamin D suppresses the immune system. This allows for chronic infection and inflammation to continue.

Over time this leads to microbiome imbalances (ie the "bad guys" are outnumbering the "good guys") and a depletion of resources like nutrients required for cellular function.

The result?

Chronic illness.

Who is really at risk of a vitamin D deficiency?

A true vitamin D deficiency can occur in certain situations, such as:

  • If there are genetic defects (genetic defects in the vitamin D receptor, certain mutations can lead to hereditary vitamin D resistance)
  • If you have a condition that impairs conversion of vitamin D into its active metabolites (certain liver, kidney and hereditary disorders)
  • Sick or elderly people who stay inside and have poor diets

Now, if you are concerned you may have a vitamin D deficiency, here are the steps to take to determine if that is indeed the case...

How To Treat Vitamin D Deficiency

Before we treat a vitamin D deficiency, we need to confirm you actually have a vitamin D deficiency... or, if as outlined above, it's simply a reflection of an inflammatory process.

Testing is key.

"Low 25(OH)D does not cause age-related diseases and mortality." (PMID: 23128285)

I recommend having the following blood chemistry markers tested to assess vitamin D deficiency:

  • Magnesium RBC (red blood cell) - magnesium is the key catalyst for creating both the storage and active forms of vitamin D
  •  25(OH)D - this measures the storage form of vitamin D (the precursor to the active form)
  • 1,25(OH)D3 - this measures the active form of vitamin D
  • Ionized Serum Calcium - it's vitamin D's job to push more calcium into the blood stream so it's a good idea to assess how much calcium you have, too

Those are most valuable in assessing vitamin D deficiency. If you wish to take it one step further and assess the other nutrients involved in vitamin D's metabolism, as well as the inflammatory process I recommend adding the following markers:

  • Ferritin - to measure the protein that stores iron in the tissues
  • Ceruloplasmin - to measure bio-available copper, which regulates iron
  • Serum Copper - to measure the total amount of copper in your blood
  • Plasma Zinc - to measure the amount of zinc in your blood
  • Retinol - to measure the amount of active Vitamin A in your blood

And to take it even further to assess the root source of inflammation, I recommend the GI-MAP DNA Stool Analysis via Diagnostic Solutions (a one time stool collection), which will rule out the possibility of stealth infections in your gut that may be causing the inflammation in the first place.

And, if you do need to increase your vitamin D levels, here are...

The Best Vitamin D Sources

1. Vitamin D From The Sun

We are "light beings." Remember, you may be twice as likely to die from all cause death if you avoid sun exposure.

Like plants, sunlight is one of our "non-negotiables." Sunlight is a key factor in the state of our health.

Sun exposure has a multitude of benefits in addition to vitamin D metabolism, including stimulating the release of:

Sunlight also resets our circadian rhythm. Exposure to bright light during the day sends messages to our pineal gland, which regulates melatonin production - the hormone that prepares our body for sleep.

Disruption of our circadian rhythm underlies many disorders, such as mood disorders, cognitive defects, and metabolic syndrome.

I recommend getting sunlight exposure before 10 am on your skin and eyes. Do not use sunglasses. 

Remember, 10-15 minutes twice per week may be enough to optimize your vitamin D stores, so do the best you can to get outdoors.

2. Vitamin D Rich Foods does a great job summarizing the top vitamin D rich foods:

vitamin d in food


Food labels don't tell the whole story since they include only D3 levels. So there may be a discrepancy between dietary intake and measurement of vitamin D status.

An interesting aside: Foods in the nightshade family like eggplant, peppers and potato contain the active 1,25D form of vitamin D. Individuals with autoimmune conditions often "react" to these foods... could it be because their 1,25D levels are already high?

3. Cod Liver Oil

Cod Liver Oil (CLO) is a great source of naturally occurring vitamin A (Retinol), omega-3s and vitamin D.

The brand I recommend is Rosita Real Foods Extra Virgin Cod Liver Oil. They are a company that posts independent lab results, their product has ensured freshness, and they are transparent about their manufacturing process.

rosita cod liver oil

For adults, start slow and build up to a dose of CLO that delivers 900 mcg / 3,000 IU of vitamin A per day.

So, for the Rosita liquid CLO that would be one serving. For their capsule option it would take 7 capsules to get that dosing.

Note that cod liver oil may have a natural propensity to thin the blood.

Next Steps

If you would like help to sort out whether or not you have a vitamin D deficiency and gain a better understanding about the root cause(s) of your health concerns, I'd be happy to chat with you.

Click here to book a free, no-obligation discovery session. Feel heard, receive coaching and guidance in determining the best next steps for YOU.

Please note that no treatment is recommended / provided during that discovery call. It serves as more of a "coffee date" to see if we're the right fit to work together.

At the very least, I hope you take this information and put it into action. Share it with your the members of your health care team. Empower yourself.

Here's to loving yourself to health,

Dr. C

Special thanks to those researchers and mentors from whom I have learned: 

Dr. Trevor G Marshall

Morley Robbins and the Magnesium Advocacy Group

Stephanie Jasky and the folks at the Secosteroid Hormone D Group

Need help figuring out if you truly have a vitamin D deficiency?

Let's chat. I'm happy to help you figure things out and determine next best steps. No obligation.

Key Points To Remember About Vitamin D Deficiency

  1. 1
    Vitamin D is a steroid hormone which regulates immune system function.
  2. 2
    Photosynthesis of vitamin D3 provides adequate vitamin D stores for most people. Therefore, most people can get what they need from the sun.
  3. 3
    There is no clear evidence that vitamin D supplementation to increase vitamin D stores offers any health benefits.  
  4. 4
    Vitamin D supplementation may indeed have negative effects.
  5. 5
    Low 25(OH)D levels are a reflection of disease. Seek out the root causes, such as inflammation.

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