Vitamin D and Your Immune System



Vitamin D boosts your immune system and lowers inflammation. Inflammation is what leads to more significant difficulties in fighting Covid. Studies have shown an increased chance of getting Covid with lower than optimal vitamin D levels. Update – As summarized by NewsWise: “New data from a recent study indicates that active forms of Vitamin D can inhibit the replication and expansion of Covid-19.” Previous advice on using Vitamin D to fight Covid-19 was based upon decades of knowledge about vitamin D’s role in the immune system, and comparisons of the vitamin D status of Covid patients and their outcomes.  This is one of the few studies to look at how vitamin D effects Covid-19 specifically.  The study also found that lumisterol, which is a compound our skin creates when exposed to sunlight, is able to BLOCK two specific enzymes required for the SARS-CoV-2 life cycle!  On top of the new findings about Covid, due to its ability to lower inflammation, people with optimal levels of vitamin D are associated with less heart disease, diabetes, high blood pressure, certain types of cancer, autoimmune diseases, and pneumonia!  You can see why making sure you have optimal levels of vitamin D is so important!  You can find my favorite vitamin D supplement here.

Ever notice how the flu is worse in the winter? Many say it is because we are all indoors more. Still, it is also very likely that it increases because our vitamin D levels drop due to lack of sun exposure. Keep reading to understand why this may be the case.

Sunlight is your primary source of vitamin D! Skin absorbs UVB rays and turns them into vitamin D. It is how humans have been getting enough vitamin D since, forever! Vitamin D supplementation is another way of getting enough in your system. Oral supplementation does not stay viably as active for as long as vitamin D obtained from sun exposure, so you must take it regularly. Of note, one cannot reach toxic blood levels of vitamin D from sun exposure alone. You can reach toxic levels from oral supplementation, although you would have to take extremely high doses.


1. Angle of the sun – time of year. Living further north or south of 33 degrees latitude will determine how many months of the year you will be able to produce vitamin D. Some cities in this latitude are Atlanta GA, Los Angeles CA, Casablanca Morocco, Baghdad Iraq, Saga Japan, Santiago Chile, Sydney Australia, and Cape Town South Africa. People who live in Boston at 42 degrees latitude can essentially make no vitamin D between the months of November and February. Time of day also plays a significant factor due to the angle of the sun. Virtually no vitamin D can be made before 10am or after 3pm, even in summer. Cities closer to the 33rd latitude typically experience flu outbreaks throughout the year, not just clustered in a few months.

2. Air pollution – the increase in sulfur dioxide, nitrous oxide, and ozone in the atmosphere will absorb a large amount of UVB before it reaches the surface and your skin.

3. Altitude – the closer you are to the sun, the shorter the path the UVB has to travel and typically fewer filters it has to pass through

4. Glass absorbs all UVB – so no vitamin D can be made even if you sit near a window.

5. Sunscreen use will decrease your ability to make vitamin D because they either absorb or deflect the UVB and UVA rays.

6. Natural skin pigment – the darker your skin, the longer it will take for your skin to produce vitamin D. Melanin acts as a natural sunscreen.

7. Aging – the older we get, the longer it takes for our body to make vitamin D.


The Nobel prize was awarded in 1903 for the discovery of treating tuberculosis patients with “heliotherapy.” Heliotherapy is still used all over the world to treat a variety of illnesses to this day. Sunlight exposure correlates with a reduction of developing some cancers by as much as 60%. And contrary to what sunscreen manufacturers would have us believe, sensible sun exposure to allow our bodies to make vitamin d has many benefits. Such as regulating skin cell growth and reducing the risk of skin cancer! Yes, reducing skin cancer. When we stay in the sun too long and get too much sunlight exposure and burn, we cause damage to our skin and increase our chance of developing skin cancer. While researching this post, I discovered so many benefits to sensible sunlight exposure that I realized I will need to do another post just on the health benefits of sunlight exposure, so stay tuned!


During the industrial revolution, when the skies in cities were thick with smoke, children developed alarming rates of rickets, a bone deforming disease caused by low levels of vitamin D. Its cause was unknown at the time, but eventually, scientists figured out the reason and started treating these children with sunlight exposure. It was also recognized that children with rickets had a much higher risk of developing pneumonia and other respiratory infections. They were also more likely to die from them. In the 1930s, manufacturers discovered how to synthesize vitamin D and began adding it to milk. Within a few years, they essentially eradicated rickets! Then like all things, people went overboard and fortified everything with vitamin D – from soda pop to beer, hotdogs, all dairy products, and even soap and shaving cream! But in the 1950s, there was an outbreak of hypercalcemia which is when calcium deposits in the wrong places. It was concluded incorrectly to be caused by too much oral vitamin D ingestion. So the pendulum swung the other way, and everything but milk fortification was stopped. We humans seem to be all or nothing when it comes to supplements, but as with all things, there is a sweet spot, a Goldilocks zone of vitamin D concentration. According to functional medicine doctors, that sweet spot is between 60-80 ng/ml in lab workups. Most labs report normal between 40-60 ng/ml. It is up to you and your doctor to decide what is best for you.  This is my favorite vitamin D3/K2 combo.

As a society, we lack appreciation for our body’s natural ability to heal and produce what we need to stay healthy. In the case of vitamin D, this has led to a worldwide population where over 50% and some say 75% of us are vitamin D deficient! It’s shocking to think how much better we would have fared if we had all had optimal vitamin D levels at the start of 2020. But now that you know how beneficial it is, you can start to optimize your levels and stay healthier in the long run.

*All of the above information was gathered through this extensive article

If you would like more in-depth information, I encourage you to check it out.

**UPDATE References

*** Some of the links on this page may be affiliate links.  Fitlosophy is a participant in affiliate programs to provide a means to earn advertising fees by linking to products that Dawn uses and trusts.  If you purchase a product through an affiliate link, your cost will be the same, but Dawn will automatically receive a small commission.  Your support is greatly appreciated and helps me spread my message!

Dawn Giammalvo

After hearing about Pilates for a few years and even working out on an in-home reformer, Dawn decided to attend her first Pilates class in 2005. Little did she know that her life would be changed that day and the path to Fitlosophy would begin. Her instructor; who not only trained with Joseph Pilates but is also a physical therapist, pointed out that she had scoliosis. No doctor had ever diagnosed her with that before even though she had been dealing with back pain for over a decade. With the help of her instructor, she learned the principles behind Pilates and what she needed to do to relieve her pain and build her strength.

What is a Health Coach?

Health and wellness coaches partner with clients seeking self-directed, lasting changes, aligned with their values, which promote health and wellness and, thereby, enhance well-being. In the course of their work health and wellness coaches display unconditional positive regard for their clients and a belief in their capacity for change, and honoring that each client is an expert on his or her life while ensuring that all interactions are respectful and non-judgmental.

What’s The Big Deal About A National Certification for Health Coaching?

Coaching has been around for a long time, there are sports coaches, career coaches, life coaches, and nutrition coaches, and in the past 10 years health coaches have come on the scene. There were never any guidelines as to who could call themselves a coach. You can choose to coach your child’s baseball team and suddenly you are a coach.

Black Friday through Cyber Monday Gifties and Discounts!

I am frequently asked what are my favorite products because my clients and friends know that I have been trying to clean up all the things I use in my home as well as what I put in and on my body for years now. I am always trying new products, but all of the products listed below are tried and true favorites. I hope you enjoy checking these out and hopefully get some Christmas shopping done as well!

Perfect Butternut Squash Soup

well y’all, i am not a food blogger, nor do i play one on tv, but this is a tasty soup! it has gotten pretty chilly here, and we even had a few snowflakes the other day, so that means it is time to make soup. last winter, i came up with this recipe after all the butternut squash soup recipes i found included apples or something sweet, and i just wasn’t feeling it. feel free to skip to the end if you just want the recipe – because sometimes life moves too fast to read all the things.

Thermography – A Tool for Early Breast Cancer Detection

Improving Our Chances to Catch Breast Cancer Early and SurviveWe all know that October is Breast Cancer Awareness Month; we’ve been hearing that for years. We are more than aware of breast cancer. We all know someone or know of someone who has had it or is currently fighting it. 1 in 8 women in the US will develop breast cancer in their lifetime.

Vitamin D and Your Immune System

Vitamin D boosts your immune system and lowers inflammation. Inflammation is what leads to more significant difficulties in fighting Covid. Studies have shown an increased chance of getting COVID with lower than optimal vitamin D levels. Update – As summarized by NewsWise: “New data from a recent study indicates that active forms of Vitamin D can inhibit the replication and expansion of Covid-19.

5 Ways to Fire Up Your Metabolism and Keep It That Way!

Metabolism can be defined as the process by which our bodies convert what we eat and drink into the energy we need to fuel all the basic automatic processes like breathing and cell division as well as the energy needed to walk, run and all the other activities we choose to do. Metabolism tends to slow with age making it easier to add on a few pounds and difficult to get them back off again.

Why am I starting a new career as a Health Coach?

The answer is long and not fully known by most people, but I thought it fitting that I put it into words in this first blog post so that you understand my motivation and maybe will decide to work with me one day. I warn you this is on the long side, but I promise future posts will be much shorter

Why Disposable Masks May Be Doing You and the Environment More Harm Than Good

This post is NOT a pro or anti-mask rant, everyone made their decisions long ago about the efficacy of masks. This is hopefully an eye-opening look at the dark side of disposable masks. After reading this post, I hope you will strive to make healthier choices about the masks you decide to wear. Better for you and better for the environment. Because disposable masks truly are doing more harm than good.

Easy Ways to Get Better Sleep Tonight!

if you are having trouble sleeping or you are not waking up rested and refreshed, consider trying some of these suggestions and see if it helps. I look forward to hearing about your experiences!

Minestrone Soup

Soup, my goodness how I love a good bowl of soup and this is one of my favorites! my mother-in-law gave this recipe to me years ago and until I went digital, it was the most stained and ragged little index card you ever did see. That, by the way, is how you know that there is magic written on that recipe card! you know what I am talking about.

New Year’s Resolutions

Today is the day, this is the year you are going to make all those changes you want to make in your life! Have you said that to yourself before? How did it work out? Want to learn some easy steps to make this year different? To actually make and KEEP those changes? Read on….

Thanksgiving Dinner: Healthier Subs that Taste Amazing!

There you have it! The first recipe roundup I’ve ever at Fitlosophy! I hope you have found it helpful and it has made your Thanksgiving prep a little easier! Make sure all the things on your table will make your body happy and not make you feel ill so that you can enjoy the day, and then most importantly, enjoy this day with your loved ones. Eat all the things – without guilt. Laugh, love, and cherish what is most important. Until next time friends, take care and stay well!


Gain a fresh perspective on healthy living.

Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.