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Vitamin D Status Matters

Through the years, vitamin D has most been correlated with strong bones due to its help in preventing Rickets, but this vitamin (which is more like a hormone) has a lot of functions in our bodies and has recently been noticed to help improve the outcomes of patients infected with coronavirus. Although research has proven vitamin Ds importance to overall health, “along with magnesium and zinc deficiencies, vitamin D is one of the most important nutritional deficiencies we face,” says Dr. Jacob Teitelbaum, MD. According to NHANES data from the Second Nutrition Report, an estimated 42% of Americans are vitamin D deficient4.

Vitamin Ds Myriad Uses

Vitamin D, along with regulating bone remineralization and health, has receptors for its absorption in the intestines, kidney, bone, cardiac, muscle, brain, skin, liver and immune cells; meaning the whole body uses it.  It’s important for a myriad of processes including signaling the release of parathyroid hormone, involvement in the conversion of your thyroid hormones to their active form, regulation of calcium and phosphorus absorption, maintaining proper blood sugar levels, helping the gut microbiome produce vitamin B5, the influence of gene transcription, regulation of the immune response, and more.

Vitamin D deficiency symptoms

Vitamin D deficiency symptoms are subtle and can also look like a lot of other imbalances but it is easily assessed by your doctor (or me) through a lab test. The most common symptoms are lowered immunity and/or impaired wound healing, fatigue, depression, bone mass loss, muscle pain not attributed to exercise, low thyroid, loss of hair or skin issues. Coupled with a poor diet, sleep deprivation and high stress (sound like most Americans you know?) then vitamin D deficiency can create susceptibility to a lot of illnesses and infections.

Vitamin D levels & COVID-19

In October 2020, in the Journal of Steroid Biochemistry and Molecular Biology (Volume 203), there was a study published outlining the effects of calcifediol (25-hydroxyvitamin vitamin D) treatment on people with COVID-19 infections2. Researchers randomly assigned 76 people with moderate to severe COVID-19 into a vitamin D dose group (50 patients) or a placebo group (26 patients) on the day they entered the hospital. In the placebo, or no vitamin-D group, 13 out of 26 patients (50%) were admitted to the intensive care unit (ICU), and two, unfortunately, died due to COVID-19 complications. In the vitamin D dose group, only 1 person out of 50 required ICU admission and there were no deaths. This means that vitamin D treatments in the hospitalized COVID-19 patients significantly reduced (by 93%!) the need for intensive care unit admissions among hospitalized patients.

In another study, researchers Backman et al. from Northwestern University analyzed patient data from 10 countries: United States, United Kingdom, China, Italy, Germany, France, Spain, Switzerland, South Korea, and Iran3. After studying the global data, the researchers discovered a strong correlation between vitamin D deficiency and COVID-19 mortality rates.

Backman and his team at Northwestern were inspired to examine vitamin D levels after noticing unexplained differences in COVID-19 mortality rates from country to country. Some people hypothesized that differences in healthcare quality, age distributions in population, testing rates or different strains of the coronavirus might be responsible. But Backman remained skeptical. “None of these factors appears to play a significant role,” Backman said. “The healthcare system in northern Italy is one of the best in the world. Differences in mortality exist even if one looks across the same age group. And, while the restrictions on testing do indeed vary, the disparities in mortality still exist even when we looked at countries or populations for which similar testing rates apply. “Instead, we saw a significant correlation with vitamin D deficiency,” he said.

In early April 2020, vitamin D serum levels and severity of COVID-19 in 212 patients in three separate hospitals was studied. According to the study1  “The results suggest that an increase in [vitamin D] in the body could either improve clinical outcomes or mitigate worst (severe to critical) outcomes, while a decrease in [vitamin D] in the body could worsen clinical outcomes of COVID-2019 patients.”  Basically, those who were deficient in vitamin D had more critical cases than those who had normal vitamin D levels: 86% of all cases among patients with normal vitamin D levels (>30 ng/ml) were mild, while 73% of COVID-19 cases among patients with vitamin D deficiency (<20 ng/ml) were severe or critical.

More research is needed but these two studies show how important vitamin D is to your overall immune system health.

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“Normal” Levels are not Optimal

Lab ranges for Vitamin D given by conventional doctors are from 30 to 100 ng/mL. If you are below 10, you are severely deficient, 10-30 ng/mL, the Endocrine Society and the Vitamin D Council still maintain that you are not getting enough, but the National Institute of Health sates that 30-50 mg/mL is generally considered adequate for bone and overall health. Naturopaths and functional medicine practitioners, however, recommend a level between 60 to 85 ng/mL for optimal health.

Getting your vitamin D levels tested regularly is something I recommend for all clients.  When deficient I recommend supplementation.  Supplements of cholecalciferol, D3, is recommended over D2, ergocalciferol, for absorption.  Also, you want vitamin K with your D unless you have blood thinning considerations.  Vitamin D3 and K2 work together to strengthen your bones and improve your overall health; bone and immune system.  Vitamin D creates vitamin K2-dependent proteins to move calcium around, so, if you’re taking vitamin D as a standalone, you’re creating an increased demand for K2 which may decrease bone strength and cause you to be more vulnerable to infections.

Supplement with Vitamin D3/K2 at 5,000 IU (125 mcg) per day with retesting every three months till your levels are optimal.  Most doctors will readily run this test for you, or I can do it.  You want to ensure your levels are optimal, not low or too high.  My go to supplement is Vitamin D Supreme with Vitamin K1 & K2 from Designs for Health available through Wellevate if you are interested.

Sunshine for Health

Sunlight is best for vitamin D optimization.  When your skin makes vitamin D it also makes two water soluble sulfur based chemicals that are not available when you take fat soluble vitamin D supplements; vitamin D from the sun converts at 100% (as opposed to 50% from dietary absorption).

It doesn’t take long to get the amount of vitamin D you need if you are fair skinned, and, as soon as your skin is even the slightest bit pink, you are no longer absorbing it.  For me, being fair skinned, I start out in the spring with about 5 minutes of full sunshine exposure daily and work up slowly so that my skin never gets pink.  After I soak up some sun then I cover up or put on sunscreen. In the fall/winter, because I live in a northern area (above 33 degrees latitude), I supplement, as I live too far north to get the right angle of sun exposure to absorb the UVB radiation needed for vitamin D synthesis.

The darker your skin the more sun exposure you need because darker skin protects against vitamin D absorption. It’s also hard for darker skinned individuals to notice the pink color that fair skinned individuals get from sun exposure. Best thing to do if you have dark skin is to get your levels tested and when using sun for absorption to build up slowly since you won’t see early warning signs to too many UVA or UVB rays.

*Update as of 1/11/2021 – there are now more than 20 peer reviewed published studies showing the correlation of vitamin D status with COVID disease severity! Get your levels checked, and if you aren’t at an optimal level, you should be taking a quality D3/K2 combo to help your immune response and your bone health.


  1. Vitamin D Supplementation Could Possibly Improve Clinical Outcomes of Patients Infected with Coronavirus-2019 (COVID-2019), April 9, 2020, by Mark Alipio –
  2. Effect of calcifediol treatment and best available therapy versus best available therapy on intensive care unit admission and mortality among patients hospitalized for COVID-19: A pilot randomized clinical study , Oct 2020, Castillo et al. –
  3. Northwestern University. (2020, May 7). Vitamin D levels appear to play role in COVID-19 mortality rates: Patients with severe deficiency are twice as likely to experience major complications. ScienceDaily.
  4. Prevalence and correlates of vitamin D deficiency in US adults –


Erin Williams, MSN CN LMP, is the founder of, a health and wellness company established in 2001. Erin has a bachelor’s degree in Chemistry from Purdue, a master’s degree in Nutrition from Bastyr University, and is currently studying to become a Functional Medicine Practitioner. Erin enjoys sharing her love of natural health and wellness with people through lectures, blogs, and consultations.

Post Author: EZBalanceWellness