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Vitamin D and the histamine & mast cell connection

Vitamin D is known as the sunshine vitamin.

It is a fat-soluble vitamin present in small amounts in foods such as egg yolks, butter, and liver.

Vitamin D is an incredibly important nutrient with hundreds of functions in our bodies. Some of its functions include bone health, calcium metabolism, gut health, immune function (including mast cells), muscle function, brain development and research has shown that it has anti-cancer properties. (1)

Despite the recognition that it is vitally important to human health, over 41% of the population in the US is deficient (2). That's almost half of our population!

How Sunshine Makes Vitamin D

When UVB rays from the sun hit your skin, it converts 7-dehydrocholesterol (an oil in your skin) to vitamin D3. D3 then must journey to the liver where it gets converted to 25- hydroxyvitamin D.

Then it continues its journey to the kidneys where it undergoes another conversion and becomes 1, 25 dihydroxyvitamin D (1,25(OH)2D), which is the active form that our bodies can utilize. Pretty amazing, and quite the journey it takes!

Every step along the way needs to function well in order for us to properly make our own Vitamin D.

Not Enough Sunshine

Today, most people don’t spend enough time outside to reap the benefits of the sun’s UVB rays.

Instead, we have jobs that are indoors, we may have hobbies or recreational activities that are indoors, or we may live in a cold climate that typically means spending more time indoors. Additionally, many people commute in cars or public transportation rather than walk, bike or travel in some other way that provides sun exposure.

With concerns over skin cancer risk, the use of sunscreens is encouraged. Here's the clincher: sunscreen reduces our exposure to UVB rays, inhibiting vitamin D production.

Is it any wonder that so many people are deficient in vitamin D?

Vitamin D, Mast Cells & Histamine

Vitamin D acts on cells in the body by binding to vitamin D receptors (VDRs). Through this action, it is involved in hundreds of functions in the body.

When vitamin D binds to receptors on mast cells it inhibits mast cell activation (3) and contributes to mast cell stabilization (4). This means that with adequate levels of Vitamin D in our systems, we are now able to calm our mast cells, and slow down the release of histamine! This can mean a reduction in what's driving our symptoms.

Conversely, low levels of vitamin D are correlated to many symptoms associated with mast cell activation (5). This is important information for those of us who are working through histamine-mediated symptoms, and offers us another window in to how to support a reduction in our symptoms.

VDR Genes & Status

In addition to time outside in the sun, there are a variety of reasons why your vitamin D levels might be low. These can include:

  • Skin pigmentation – the more melanin you have (the darker your skin) the more UVB exposure you need

  • Age – the older you are, the less vitamin D you are able to produce

  • Latitude – the further you are from the equator, the less UVB exposure you’ll have

  • Weather & season – cloud cover reduces UVB exposure

  • Chronic illness – can deplete vitamin D

  • Gene variations

VDR genes impact VDR activity. When vitamin D binds to these receptors, you can have increased or decreased activity which then impacts all the physiological functions of vitamin D, including mast cell stabilization. If you have gene variations that indicate decreased activity, you will require more vitamin D.

With so many factors impacting vitamin D levels, it is important to find a functional or integrative doctor who can test your vitamin D levels and determine if your vitamin D status warrants supplementation.

Vitamin D status must be monitored on a regular basis when supplementing so that it remains in a healthy range.

3 Steps to Take

  1. Get outside every day and practice safe sun exposure. Expose as much skin as you can early in the day or late in the afternoon when risk of burning is minimal. Do this without sunscreen on. Prioritize this, and aim to get in the sun's rays in that first hour of the sun getting up, if you can. Be consistent! Make sure to protect your skin with clothing / layers / brimmed hat, or sunscreen mid-day or any time you are at risk of burning.

  2. Consume foods rich in vitamin D3. Enjoy fatty low histamine fish like salmon (cooked from frozen is best to keep histamine content low), ghee, lard from pasture-raised pigs and egg yolks from chickens that have access to outdoors. They too need sun exposure in order to store that extra Vitamin D3 in their eggs!

  3. Get your levels tested by a functional or integrative doctor to find out if supplementation is required.

To find out some of our favourite brands of vitamin D, check out our account on Fullscript by clicking here.

Click on Catalog in the top menu bar and then click on Favorites. You’ll see our top picks there. For those in Canada, you can purchase from there, too. We set everyone up with a 15% discount!


Curious to understand this histamine connection and tie it in to your symptoms a little bit more?

Consider joining us at our next live class we call The Histamine Connection. It's a free Master Class that is designed to help you make that connection to how histamine & mast cells are impacting your day to day life, and how nutrition can be of support.

Register for the next live class (listed on the left of the page), or register for the pre-recorded version (listed on the right). You can register for either class here.

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