Vitamin D & Safe Sun Exposure

We all know about vitamin D. It’s like America’s sweetheart nutrient. You’ve no doubt got a bottle of it sitting in your cabinet right now (whether or not you should take it…different story). Today, let’s chat about what vitamin D does, how to naturally increase our levels, and what safe sun exposure really means.

Or...just scroll all the way down for the Cliffs Notes ;)


There’s no wonder we’re all talking about Vitamin D: it’s extraordinarily important and has many roles within the body. In fact, it’s more like a hormone than a vitamin. Vitamin D is necessary for calcium absorption and bone health, as well as the function of your immune system, muscles, heart, lungs, and brain. Yeah. Every single cell in your body uses vitamin D.


There are 2 ways to naturally get vitamin D:


1. Diet

Foods that naturally contain small amounts of vitamin D:

  • fatty fish (salmon, sardines, mackerel, tuna)

  • raw full fat dairy

  • cod liver oil

  • egg yolks from pastured chickens

  • beef liver

These are not really foods our culture eats on the reg, so much of our processed food is supplemented with synthetic vitamin D.


2. The sun’s UVB rays

Our skin naturally produces vitamin D when it is exposed to a pinking dose of sunlight.

The vitamin D we produce on our own through the sun is the gold standard of this nutrient.


Not So Heavy D

Due to our fear of the sun, and our modern diet of processed foods, vitamin D deficiency is common. This isn’t good. D deficiency is linked to bone disease, depression, acne, psoriasis, autoimmune diseases, obesity, heart disease, fibromyalgia, and many types of cancer.


Who is especially prone to vitamin D deficiency?

Breastfed infants

Pediatricians are now recommending that breastfeeding moms give their babies vitamin D supplements. I promise to write a blog about this soon, because it’s a question I get a LOT from new mamas. Here’s the extremely short version: The vitamin D content of breastmilk is related to the mother’s vitamin D status. In other words, if mom is low, her milk will be low, and baby won’t get enough. Here’s a better option: mom can get outside in the sun as much as possible, eat lots of vitamin D-rich foods, and potentially take a clean vitamin D supplement*.

People who live in northern regions

Those who live above the latitude line connecting Richmond, VA to Portland, OR only get enough radiation from the sun for vitamin D production part of the year. Seasonal focus on D-rich foods, a Vitamin D light box or D supplementation* is a good idea. 

People who spend most of their time indoors & lack exposure to sunlight

Those who work inside, or are covered up (with clothes or shade) when they do go outside, are at risk of low D. The same is true if you cover up with sunscreen EVERY time you head outdoors: sunscreen with an SPF of 15 or greater blocks 100% of vitamin D production in the skin. Try to get more exposure to the sun. If you can’t do this, diet, light therapy and supplementation* are key.

People with darker skin

Greater amounts of melanin (a pigment in the skin) reduces the skin’s ability to produce vitamin D from sunlight. Greater exposure to sunlight is important.

People with inflammatory bowel disease, poor gut health and/or those on low fat diets

Vitamin D is a fat soluble vitamin - it needs fat in order to be absorbed. Therefore appropriate vitamin D levels are contingent upon getting adequate fat in your diet AND your gut’s ability to absorb fat. It’s especially important for these folks to get vitamin D through SUN!


Who’s Afraid of the Big, Bad Sun?

Murda, murda, murda, kill, kill, kill. These guys were definitely rapping about the sun.

Murda, murda, murda, kill, kill, kill. These guys were definitely rapping about the sun.

We need Vitamin D to stay healthy - including the prevention of cancer - and we need to get Vitamin D from the sun. 

But we're all terrified of it.

Unfortunately, being afraid of the sun isn’t doing us any favors. Despite greater sunscreen use and sun awareness, melanoma cases rates in Americans continue to rise.

People who spend the least amount of time outside have the highest risk of malignant melanoma (the most aggressive and life-threatening form of skin cancer).

Humans need sunshine to thrive.

But too much of a good thing is too much. Overexposure to UV light can absolutely damage the skin, leading to photo aging and cancer. We must consciously get an appropriate amount of sun. This amount is different for everybody. 


How to determine your own unique sun exposure threshold:

Look for the pink.

UVB rays are sometimes considered “burning rays”. It’s like your own built in sun protection; your skin will turn slightly pink when you’ve been exposed to enough.

Ideally, you want to get out of the sun right before - or right as - your skin is turning that faint hint of pink. 

On average, without sunblock and with arms and legs exposed, your skin will make 10,000 to 15,000 units of vitamin D in one pinking sun exposure.

The bad news: UVA rays provide no warning. These rays penetrate deeper and create oxidative damage associated with malignant melanoma. You have no way of knowing how much you’ve been exposed to, which is why it is imperative to rely on that pinking mechanism, and then get out of the sun or seek cover. While UVB rays are filtered through glass or windows, UVA rays are not. People who spend the most time behind glass have the highest risk of malignant melanoma. 

Essentially, we want to find a balance of getting enough sun exposure to produce Vitamin D, while not overexposing our skin and putting us at risk for skin cancer. Once we’ve reached our threshold, we then need to seek out a physical barrier to protect our skin from the sun. 

This physical barrier can be one of three things:

  1. Shade

  2. Clothing/hats

  3. A mineral based sunscreen

While sunscreen shouldn’t be your first line of defense against the sun, there are times when you just WANT to be outside in the sun! This is my all-time favorite sunscreen for both myself and family. If you'd like some more information on sunscreen, check out my Guide to Safe Sunscreen. I talk about what to use, what to avoid, and why.


*Should you supplement with Vitamin D?

My child's pediatrician once told me that vitamin D supplements are "benign". This couldn't be further from the truth. Throughout human history, we have had regular UVB exposure - this is how we've always made our vitamin D, and this is what the body knows. When we flood the body with supplemental vitamin D, we also dial back certain body processes that are necessary for health.

With UVB exposure, your skin not only generates vitamin D, but also sulfates cholesterol. This step is necessary for gut health, immune regulation and fighting off infection.

Vitamin D supplementation is not one size fits all. Some supplementation may be better than nothing. But if you have access to the sun, getting exposure (without any sunscreen) is more beneficial to overall health - immunity, reduced cancer risk, reduced heart disease risk - than taking a vitamin D supplement.

When supplementing with D - and other nutrients - it's important to work with a practitioner who can evaluate your risk and determine whether supplementation is appropriate. 

If you are supplementing with D, be sure to have adequate vitamin A and K2 in your diet, or supplement with these vitamins simultaneously. 

Consider a vitamin D light box. This is especially great if you live in high latitudes, like us in the Northeast (oh, oh New England).

Do not supplement with vitamin D2 (ergocalciferol). D2 is the "vegan" form of the supplement, as D3 comes from lanolin is sheep's wool. There are too many question marks surrounding the safety and effectiveness of D2. Unfortunately, D2 is often found in dairy free nut milks, so be on the lookout for ingredient lists. 


Remember, diet matters.

(Of course it does.)

A great way to protect your skin from the inside out is to give up the Standard American Diet in favor of an antioxidant-rich, anti-inflammatory diet (like this one!). Think lots of fruits and veggies, fresh herbs, spices, well sourced meats, raw grass fed dairy, raw nuts and seeds, and healthy, whole food fats (no vegetable oils).


Cliffs Notes Version:

  1. We need some sun exposure for vitality and health.

  2. The best sun protection is a physical barrier between your skin and the sun.

  3. Zinc oxide acts as a physical barrier; seek out zinc-based sunscreens.

  4. Sunscreen sticks are the best.

  5. Avoid chemical sunscreens, and never use sprays.

  6. Protect ya neck with a good diet that includes foods with naturally occurring vitamin D, healthy fats & antioxidants.

  7. Work with a practitioner to determine whether vitamin D supplementation is appropriate for you.