The truth about your vitamin D level

Why you need it for an immune system against COVID

Vitamin D is technically not a vitamin. It is actually a fat-soluble cholesterol derivative steroid hormone that can be made inside the body if one is exposed to sunlight.

It has been nearly a year since COVID-19 was declared a global pandemic.  In that time, there has been abundant debate over the efficacy of masks, social distancing, lockdowns, experimental mRNA therapies aka “vaccines”, and prescription drugs.  The data and evidence about these topics are far from complete or contradictory, depending on the source.  The discussion and guidance about basic nutrition, exercise, and supplementation with respect to infectious disease have overall been far and few between in the mainstream, if not ignored completely.

This article aims to inform the reader on how one can bolster one’s immune system naturally to mitigate proactively the risks of infectious diseases including COVID-19.  The immune system is our first line of defense and, if the immune system is functioning optimally, it is superior to anything offered by science.

Here are the most common variables in the immune system equation.

Vitamin D is technically not a vitamin.  It is actually a fat-soluble cholesterol derivative steroid hormone that can be made inside the body if one is exposed to sunlight, more specifically the UVB range of the spectrum.

Vitamin D has been known to regulate calcium in the body but more attention has been placed on it in recent years since it directly regulates immune system function as well.

The rule of thumb is that sun exposure is optimal if one is exposed to sunlight daily for a duration of time that is about 50% as long as it would take you to get a sunburn.

Therefore, non-white individuals would need the greatest amount of sun exposure to fulfill their daily requirements.  This is reflected in Western studies of COVID-19 infection rates that are directly proportional to the amount of vitamin D that is active in the bloodstream. It can be seen in the following graph that Caucasian individuals are the least likely to be deficient while all other ethnic groups, i.e. Asian, Latino, and black, can be as high as 80% deficient especially if they live above the 35th parallel.

Calls by health experts for the average ‘non-essential’ personnel to remain indoors would further contribute to falling serum vitamin D levels

Furthermore, in the following graphic of historical data of other infectious diseases like the flu, the rate of infection is also directly proportional to the level of vitamin D in the bloodstream, similar to COVID-19.  As the sun weakens in intensity and cold weather forces most of the population to remain indoors, serum vitamin D levels steadily declines while infection rate simultaneously rises.  Calls by health experts for the average “non-essential” personnel to remain indoors would further contribute to falling serum vitamin D levels that result from decreased exposure to sunlight.

This graphic helps explain why the rate of COVID-19 deaths in the Philippines has been relatively static while Western nations have seen seasonal spikes in COVID-19 deaths in direct proportion to dropping levels of vitamin D in the bloodstream.

To further illustrate, in the case of Sweden, COVID-19 deaths fell to near zero during their summer season but the trend sharply reversed as the cold season set in, where they experienced a gradual increase in case fatality rates that reflected the following:

The skin-whitening culture has created an environment where vitamin D deficiency is relatively common

In equatorial nations like the Philippines, vitamin D deficiency is relatively rare on a per capita basis with respect to people who work mostly outdoors.  However, in the Philippines, the skin-whitening culture has created an environment where vitamin D deficiency is relatively common, especially in the middle and upper classes that spend most of their time indoors even before lockdowns when that time indoors increased further.  According to The National Human Activity Pattern Survey (NHAPS), the average person spends 7.6% of their time outdoors in a non-pandemic scenario:

The following is a graph of the mortality rate relative to their proximity to the equator.  Other than the Philippines, nations like Haiti and Nigeria have experienced only a small fraction of the COVID-19 deaths when compared to Western nations that are located at higher global latitudes:

Other than the sun, it is possible to raise serum vitamin D levels by ingesting it orally, with vitamin D3 being the form most readily converted by the immune cells, liver, and kidney’s to its active 25-hydroxy form.  This can be done by either supplementation or from food.  The most common food sources of vitamin D are fish oil, egg yolks, and red meat.  Unfortunately getting vitamin D from food sources alone, without sunlight and/or supplementation, is impractical for most, if not impossible.

Forms of fructose, like what is found in fruit, could also potentially inactivate vitamin D  

It is important to note that the active 25-hydroxy form of vitamin D can be inactivated by an overabundance of high-fructose corn syrup in the diet.  One could be either ingesting plenty of vitamin D or spending enough time in the sun, but it would be for nothing if the overall diet is extremely poor in quality.  High fructose corn syrup is a common food additive used as a sweetener, found in most commercial processed food.  Other forms of fructose, like what is found in fruit, could also potentially inactivate vitamin D.

Therefore, as in all things, moderation is key with respect to the intake of fruits and any food that contain high-fructose corn syrup.

There is also direct correlation between body mass index (BMI) and vitamin D deficiency.  The greater the BMI of an individual, the more likely they are to be deficient.  Adipose tissue such as fat cells readily pulls vitamin D from the bloodstream to make it unavailable for cellular metabolism and conversion to its 25-hydroxy form.  This process explains why those who are considered obese are affected the most severely when infected with COVID-19.

Vitamin D levels are considered deficient if below 30ng/ml in the blood.  Optimal levels of vitamin D range between 51-70ng/ml.  When vitamin D levels exceed 100ng/dl, that is considered to be “too high”.  Medical organizations differ on these ranges, however.  Therefore, the only way to be certain about how much vitamin D one needs to achieve the “optimal” range is to do the bloodwork ordered by a doctor.

Age is also a factor, in that those aged 70 and above lose their ability to produce vitamin D in the skin by a factor of two fold.  This decline is gradual after age 18.  Studies have also associated that outcomes for vitamin D-deficient hospitalized older patients worsen with decreasing serum vitamin D levels.

Critical function of magnesium

It is important to note that none of these studies measured the amount of magnesium in the body.  According to the National Health and Nutrition Examination Survey (NHANES), 79% of US adults are deficient in magnesium.  It would be a fair assumption that the westernized diet of the Philippines would demonstrate similar deficiency numbers.

Magnesium is critical in the regulation of vitamin D in the body, specifically in facilitating conversion to the active 25-hydroxy form when sufficient magnesium is present. Studies have shown that when magnesium was administered, 25-hydroxy vitamin D levels immediately increased and patients were overall far less likely to have low levels of vitamin D.

Common magnesium supplements commercially sold are generally not well absorbed in the body. For example, magnesium oxide supplements are only 10% absorbable. If the supplement contains 100mg of magnesium oxide, only 10mg can be absorbed by the body.  Therefore, a label claim that the supplement supplies 24% of the RDA is misleading.

To make matters worse, many magnesium formulations combine their magnesium with calcium.  Calcium and magnesium are antagonists relative to one another and will be rendered inert or not absorbable if taken at the same time.

So the best nutrition strategy would be to avoid ingesting calcium at the same time as magnesium-rich food or supplements.  It is ideal to get magnesium from food where it is 100% absorbable.

The best sources of natural magnesium are pumpkin seeds, spinach, beans, and lentils, to name a few. Studies have shown that the immune-boosting effects of magnesium are realized in about four days.

About author


Jason Postulka graduated from the University of Illinois-Chicago with a degree in biochemistry. He was director of Eclipse Fitness Center from 2006-2016, coaching athletes from the PBA, NCAA, and UAAP in strength and conditioning as well as performance nutrition. He is a private analyst, consultant, and trader in the biotechnology sector.
Dr. Lourdes Deliosa is a specialist in internal medicine. She graduated from Far Eastern University (FEU-NRMF) in 1997, and finished her residency at Manila Doctors Hospital. She holds clinic at Mandaluyong City Medical Center, Medical Specialist and Asian Development Bank Medical Center.

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