Vitamin D – are you getting enough?


The current recommended daily intake for Vitamin D runs from 200-600 IU’s per day, depending on your age. In light of recent research, and with most people testing severely deficient in blood tests today, this level of supplementation seems to be inadequate.

Vitamin D concentration in the body is correlated with immune function (i.e. fighting off the flu and preventing cancer), and contributes in multiple ways to the optimal function of the human body because virtually every cell has a receptor for Vitamin D. This includes the cells of the pancreas which is where vitamin D has its impact on blood sugar.

Vitamin D2 vs. Vitamin D3

If you are like most North Americans, the form of Vitamin D you are most likely lacking, and with which you need to supplement is Vitamin D3 (cholecalciferol) – not Vitamin D2 (ergocalciferol). Vitamin D3 is synthesized in the skin from cholesterol in response to absorbing UVB rays. It gets converted in the liver, then is transported to the kidneys, and goes to the heart of every cell, the nucleus, and influences its physiology to take the healthy pathways by dictating genetic expression.

Most of us are lacking several thousand IU’s of Vitamin D3 per day because we spend our days indoors – and even in the summer, we move from an air-conditioned house, to an air-conditioned car, to an air-conditioned office building, to an air-conditioned bedroom for the night … Then we repeat the cycle the next day.

Blood Serum Levels 25 Hydroxy Vitamin D

The level of Vitamin D circulating in our system is directly proportionate to the amount of skin exposed to sunlight. According to Dr. Mayer Eistenstein, a medical doctor and lawyer from, and Dr. Joseph Mercola, an osteopathic physician from the world’s #1 natural health website, to have acceptable levels of 150-200nmol/L we need 10-15 minutes of mid-day sun with 40% body exposure, and for most of us this is not possible.

Vitamin D Supplementation

Traditionally, people have been taught to supplement with 1000-2000 IU of Vitamin D per day, to maintain levels above 50 nmol/L to prevent Rickets. The chart below, provided by, shows that levels should be greater than 150 nmol/L to lessen the likelihood of diseases related to Vitamin D deficiency. Vitamin D testing often reveals that most people more accurately need to supplement with 5,000 for maintenance, or 10,000 IU per day until health levels are reached and verified by follow-up testing.


Please note, the reference numbers listed above use imperial units of measure, not metric units which are otherwise referenced in this article. Canadian (metric) reference ranges are listed in nmol/L. Please note for imperial vs. metric reference ranges that 1 ng/mL (U.S./imperial) = 2.5 nmol/L (CAN/metric)

According to, Metametrix Labs,, and emerging research in this field, the following concentrations of Vitamin D3 relate to your risk of various illnesses:

< 50       Deficiency, high risk of various conditions
50-80     Insufficiency, mild risk of various conditions
80-225   Sufficiency, possibly enough in certain individuals
150-225 Most optimal, preferred range, normal in sunny countries.
This range reduces severity of various conditions and possibly necessary for optimal health in certain individuals
> 250     Possibly unsafe levels
> 375     Toxic levels, impossible to achieve with sun alone

The above reference ranges are not based on guidelines set by governing bodies, but on clinical research in the natural health field. “Acceptable” ranges advocated by governing bodies may not meet the same standards as those endorsed by today’s leaders in natural health care.

Commentary from Dr. B.J. Hardick:

A few years ago, I had my own levels of Vitamin D tested and I was severely deficient. My level of 25 Hydroxy Vitamin D was just 78 – and it should be greater than 150. While I was beyond the range where I was at risk for Rickets, I was shocked to learn that my levels were far below healthier ranges to improve my resistance to the numerous cancers now associated with Vitamin D deficiency.

Through that fall and winter, I supplemented with 15,000 IU of Vitamin D3 each day, and re-tested my levels six months later. I had reached a level of 186 nmol/L. I’ve now reduced my daily regimen to a maintenance dose of 5,000 IU per day in the summer, and 10,000 IU per day in the winter, but I will absolutely have my levels tested every year to ensure that I am getting enough Vitamin D3.

Interestingly, that same year we had a client go south for the winter after discovering her level was just 65 nmol/L – which was worse than mine. You would think that a few months of Florida sunshine would boost this level quickly – but it didn’t. This client re-tested in the spring, as I did, and was shocked that her level only increased to 68 – still massively deficient and at risk for serious illness. Realistically, we were designed to receive gradual sun exposure the entire day, not only through an intense 30 minutes of tanning. Sunscreens and cloudy days don’t help either.

Therefore, while I would love for us to get all of our nutrients through food, this is one nutrient that I know first-hand can’t be attained through a healthy diet, multivitamin, or tanning alone. Vitamin D is the one stand-alone vitamin I recommend for everyone.

Click here to learn more about the Vitamin D3 supplement I personally take on a daily basis.

The Chiropractic Perspective

More important than getting the right amount of nutrients for optimal function is your body’s ability to assimilate them. The process, guided by the central nerve system, is the most overlooked element in most nutritional supplementation programs. Chiropractic adjustments enhance nerve supply to every organ of your body. Therefore, be sure to take good care of your spine and nerve system through regular chiropractic care, so that you don’t just consume the nutrients you need, but that your body actually uses them.



Dr. B.J. Hardick

About Dr. B.J. Hardick

Dr. B.J. Hardick is a Doctor of Chiropractic and internationally-recognized natural health author and speaker. His health journey began as a child — alternative medicine is the only medicine he has ever known. In 2009, he authored his first book, Maximized Living Nutrition Plans. In 2018, he authored his second book, Align Your Health. An energizing and passionate speaker, Dr. Hardick shares his lifestyle methods to numerous professional and public audiences every year in the United States and Canada. His teachings encompass the principles of ancestral nutrition, detoxification, functional fitness, mindfulness, and green living. Learn More