Vitamin D and Covid-19: What’s It All About?

In the next week, I plan on posting information regarding trying to protect ourselves from developing severe cases and possibly even fatal cases of Covid-19.   There is so much we don’t know but more information is being released each week.    I think the most important thing is to have a safe and effective vaccine, but equally important is the understanding why some people have no or just minimal symptoms and other people get sick enough to be put on a ventilator and succumb to this illness.  How our bodies respond, can also affect how well a vaccine will work on an individual level.   As with everything, genetics probably play a part as well as our diet, lifestyle, stressors, sleep, etc.   So, this week, I will try to cover some of the things we know and possibly know about COVID-19.   A big caveat is that true science and understanding takes time, looking at large data bases with lots of information then trying to correlate that information.  Full understanding will take time.  However, there are basic things we can consider and extrapolate which may be beneficial and help to minimize risk. 

A little very simplified Science first!

Today, let’s talk about Vitamin D, but please bear with me for a little simplified science.  When we get exposed to a virus, bacteria or any other foreign substance we have multiple systems in our bodies which mount an attack on these ‘foreigners’.  Think of it as the body has been well schooled in ‘stranger danger’.   What we want our body to do with ‘stranger danger’ is to mount an EQUALLY strong response to that ‘stranger danger’, a response that creates an inflammasome (don’t need to remember the word but you may see it in other places).  Too little won’t work, too much can cause other problems.   The key is a balance.    Consider a pan of water on a stove top that you want to bring to a boil.  You can use the knob on the stove to control the response, too low a flame the water won’t boil, but too much and you now have water coming up and over the pot.  The boil over also can happen in a short second.    The COVID-19 virus is a ‘stranger danger’ and our bodies will normally hopefully mount an appropriate and balanced inflammasome response.  

Found in many of the foods we should eat are the ‘controllers’ that increase or decrease our body’s response.   In many patients, their system works perfectly, and they kill off the ‘stranger’ without making the person ill.  In others, the first line defense doesn’t work well so they move to a stronger secondary defense, so people are a little sick but more like our regular colds and flu.  With COVID-19, there are people who start to get sick, but then their ‘pot boils over’.  There appears to be a very strong inflammasome reaction from our body which is out of control, the immune system response (inflammasome) results in a ‘cytokine storm’ (cytokines are inflammatory substances) and these defenders of our body start destroying more than the virus.   The extreme inflammatory reaction can destroy the lining of our lungs, effect the kidneys and other parts of the body.  What was meant to destroy the ‘stranger’ now is causing damage to our body.  Trust me when I again state that this is a very, very simplistic version of what happens in our body. 

Now for Vitamin D.  Vitamin D is a fat-soluble vitamin that is converted in our body to an active hormone-like nutrient called 1,25 dihydroxyvitamin D.  It is used to build bones but probably more importantly it is an immune system modulator which decreases the release of inflammatory cytokines.   Think of it as the knob on the stove and will dial the heat up or lower it to give you that perfect boiling water.  As in the analogy of Goldilocks and the Three Bears, not too little, not too much— it is just right.   Therefore, having an adequate supply of Vitamin D in our bodies is very important to ‘modulation’ of  our immune system when faced with ‘stranger danger’.  

Who typically has low levels of Vitamin D in their body? 

Let’s start with how much sun you are exposed to, if you live above 27 degrees north or below 37 degrees south of the equator you are more likely to be vitamin D deficient.  If you live in Boston, you have virtually no pre-vitamin D production during the winter on cloudy days.   If you work indoors (office and health care workers).  If you wear sunscreen and never let your trunk be exposed to sunlight.  Sunlight conversion to Vitamin D on arms and legs doesn’t get you much vitamin D.  People with darker skin tones don’t absorb the UV as well, for example Hispanic and African American populations.

The elderly are also likely to have a Vitamin D deficiency because they have a lower dietary intake of vitamin D, spend more time indoors and as the skin ages it becomes less efficient at synthesizing Vitamin D from sunlight exposure.              

The Standard American Diet (SAD) tends to be low in Vitamin D.  Vitamin D is found in oily fish such as sardines, mackerel and salmon, some yeasts and mushrooms.  Some foods are fortified with Vitamin D but in general the SAD is a poor source for Vitamin D.  

People that have had gastric bypass surgery have absorption issues and lower Vitamin D levels. 

People who are obese also have lower Vitamin D levels.  This probably occurs due to that they have a higher fat mass which dilutes the Vitamin D available in the body for function; they tend to have more limited sun exposure due to greater covering of their skin.  

People with Inflammatory bowel disease such as ulcerative colitis and Crohn’s disease has reduced Vitamin D levels because of reduced nutrient absorption.  

Liver disease, cystic fibrosis, chronic kidney disease, some weight loss drugs (Xenical) and anti-epileptic medications (phenobarbital and phenytoin) also lower a person’s Vitamin D level. 

When I look at the list of people who are most likely have Vitamin D deficiency, it matches up pretty well with people who have died from COVID-19.   Could Vitamin D be the only reason—no, but I think that it could very much be a powerful contributor.   

Therefore, it is safe to consider increasing it in your diet and/or supplementing with Vitamin D3.  The Recommended Daily amounts were actually based on what we need for bones, not our immune system and is probably a minimum.  Optical range would be more than 50 ng/ml of serum 25-hydroxy vitamin D (which is what your Vitamin D test measures) and less 80 ng/ml.  

For most people, 2000 iu per day keeps you at a good number, but if you are low to start (see the above examples) with you may need 5000 iu/day or more.   

Everybody is an individual, diets and outdoor activities are different—if in doubt you can check with me for guidance.   I have also included some sources of dietary Vitamin D and how many iu you get from those sources.  As you can see, most people will find it easier to supplement in addition to dietary sources.  

Sources of dietary Vitamin D

Cod liver oil, 1 Tbsp                                                                  1360 iu

Salmon (pink, canned), 3 ounces                                              465 iu

Sardines (canned), 3 ounces                                                    164 iu

Tuna fish (canned in water, drained), 3 ounces                     154 iu

Milk (whole, 3.25% milkfat, fortified), 1 cup                          124 iu

Orange juice (fortified), 8 ounces                                            100 iu

Beef liver (cooked), 3 ounces                                                  42 iu

Egg (cooked), 1 large                                                               41 iu

Cereal (fortified), 1 cup                                                            40 iu

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