Sunshine + Vitamin D: Are You Getting Enough?

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It’s officially summer! If you have spent the last several months holed up indoors, seldom venturing outside, one of the best things you can do for your health RIGHT NOW is to spend time outdoors—every day—and soak up some sunshine.

Sunlight is essential for human health…and for immune function.

Optimal sun exposure is associated with improved immune function, and, consequently, a lowered risk of heart disease, some cancers, including breast, prostate, pancreatic and (ironically!) melanoma, osteoporosis, multiple sclerosis (MS) and Type 1 diabetes.1 Getting a healthy dose of sunshine can also boost mood, reduce blood pressure, enable better DNA repair and reduce lesions in psoriasis, eczema and vitiligo.2

A study of 29,518 Swedish women found that, across the board, those women who avoided the sun were more likely to die earlier—and from all causes of death—than women maintained active sun exposure.3 The study also found that non-smokers who avoided the sun had a life expectancy similar to smokers in the highest sun exposure group, indicating that avoiding the sun altogether has a risk factor for death—similar to smoking.4

One of the biggest benefits of sun exposure is that it enables your body to make Vitamin D, also known as “the sunshine vitamin”. Exposing large areas of bare skin to sunlight, especially ultraviolet B (UVB) rays, is one of the most natural—and efficient—ways that your body can get (and make) vitamin D.5

Are you letting (enough) sunshine into your life? 

If you spend more time indoors than outdoors; avoid the sun like the plague; slather on sunscreen every day, especially during the summer months; and / or eat a Standard American Diet (high in sugar, simple carbohydrates, refined and processed foods and/or alcohol), you are very likely Vitamin D deficient.

Vitamin D deficiency affects 50% of the population worldwide.6 In the U.S., 40% of Americans are notably deficient in Vitamin D; this means having a serum blood level of Vitamin D below 20 ng/mL (50 nmol/L), according to a 2018 study, published in Cureus.7

In the summer, a little bit of sun exposure—without sunscreen—at the right time goes a long way towards helping your body produce Vitamin D. Keep in mind: when you expose more skin with a larger surface area, like your back (versus a smaller area, like your face), you make more Vitamin D. Aim for 10 to 20 minutes around midday (12noon to 1pm), depending on your sensitivity to the sun and skin type (e.g., very fair to dark).8 Use sunscreen on your face, where the skin is more delicate, especially if you are fair (and even if you are dark-complected) and/or wear a hat and sunglasses.  Be sure to apply sunscreen afterwards.

What is Vitamin D?

Vitamin D is a fat-soluble vitamin. This means that if you take a Vitamin D supplement, it should be taken with a healthy fat, like olive oil, egg, avocado or salmon, for maximum absorption. Vitamin D is also a hormone, produced in the kidneys, that promotes calcium absorption, contributing to healthy bones. Vitamin D also regulates the immune system, cell growth and muscle function.9 Because virtually every cell in the body has a Vitamin D receptor, from your skin, breast, colon and pancreas, to your brain, teeth, spinal cord and more, many bodily processes are affected by Vitamin D.10

Is it a big deal if your Vitamin D is low?

Actually, yes. Vitamin D that is below 30 ng/ml (on a Vitamin D 25-OH test) has been associated with many chronic diseases and conditions, including osteoporosis and osteopenia; heart disease (men and women); osteoarthritis and rheumatoid arthritis; chronic pain; MS and most autoimmune diseases (e.g., lupus, Hashimoto’s); inflammatory diseases, like inflammatory bowel disease (IBD) and asthma; pain, muscular weakness; mood disorders, diabetes and pre-diabetes.11, 12 Since your skin makes Vitamin D from sunlight, many of these adverse health effects are similar to not getting enough (or zero) sun exposure.  However, before you run out and start supplementing madly with Vitamin D, it is important to test your current level of Vitamin D.

Vitamin D Deficiency Influencers

A number of factors can influence your susceptibility to Vitamin D deficiency.

♦  Where you live.  The further away you live from the equator, the less UVB rays will be available (because of the sun’s angle), affecting your body’s ability to produce Vitamin D. For example, in southern states, like Florida, your body can produce Vitamin D year-round; however, in northern cities, like New York City or Boston, you can’t make much Vitamin D between November and March.13

♦  Wearing sunscreen at all times or limiting sun exposure to early morning or late afternoon. You want some exposure to UVB rays (to make Vitamin D), and UVBs are present between 10am and 2pm.

♦  Air pollution. Polluted air soaks up UVB or reflects it back onto space. If you live in a place where there is lots of pollution, your body makes less Vitamin D.14

♦  Skin color. The darker your skin, the more time you may need to spend in the sun to make enough Vitamin D compared to someone with fair skin

♦  The amount of skin you expose. Exposing large areas of skin, like your back, is ideal. By the way: using sunscreen on your face is always recommended!

♦  Age (50-Plus).  As we age, our skin becomes less efficient at converting sun exposure to Vitamin D. At the same time, the kidneys become less efficient at converting Vitamin D into its active form. Older adults also tend to spend more time indoors.

♦  Gut problems.  If you have digestive health issues, like Crohn’s, IBD, ulcerative colitis, nonceliac gluten sensitivity, or you don’t have a gallbladder, you may not absorb fat well, including Vitamin D, which is a fat-soluble vitamin.

♦  Obesity or having had gastric bypass surgery. Studies have shown that having a higher body fat percentage and Body Mass Index (BMI greater than 30) is associated with lower Vitamin D levels.15

Can I get my Vitamin D from food alone?

The short answer? No. It is virtually impossible to get adequate amounts of vitamin D from food alone. Only a few foods naturally contain Vitamin D3 (and in relatively small amounts)—fatty fish, like sardines and salmon; cod liver oil; liver; egg yolk and butter—and these are not foods that tend to be consumed on a regular basis.16

That said, because Vitamin D is a prohormone, only 10 percent of vitamin D that your body needs will come from food; your body makes the rest.17

The two main forms of vitamin D are Vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol). Vitamin D2, a less potent form of vitamin D, is found in some wild mushrooms and fortified foods, like cow’s milk, plant-based milks, orange juice and cereals. Vitamin D3 is sourced only from animal foods and sunshine. Research suggests that vitamin D3 raises blood levels of vitamin D more effectively than D2.18

How much Vitamin D is enough?

The optimal level recommended for Vitamin D can vary, depending on who is making the recommendation. The Institute of Medicine defines Vitamin D “deficiency” as less than 12 ng/mL and Vitamin D “insufficiency” as less than 20 ng/mL.19  The Endocrine Society recommends a blood level of at least 30 ng/mL for adults to maintain bone health and musculoskeletal health.20

The Vitamin D Council defines the “Sufficiency” range (in other words, you’re getting enough D) as 40-80 ng/mL, and recommends maintaining a serum level of 50 ng/mL.21 Most functional medicine doctors and integrative practitioners recommend a Vitamin D level between 50 and 80 ng/mL to optimize the health benefits it confers. Above 100 ng/mL is considered “toxic”.

Diabetes and obesity are often linked with low levels of Vitamin D and supplementation is often beneficial.

If you have an autoimmune disease, your gut health is often compromised, making it more difficult to properly activate Vitamin D in the gut and skin. As a result, it’s likely your Vitamin D requirements will be higher.

For example, I have Hashimoto’s, an autoimmune thyroid disease. Prior to my diagnosis in 2013, my Vitamin D hovered between 25 and 32 ng/mL. I struggled with poor immunity—frequent colds and viral infections. After my Hashimoto’s diagnosis, I made a conscious effort to bring up my Vitamin D through sun exposure and supplementation.  My Vitamin D level has been as high as 143 ng/mL (I was fine. No symptoms; I simply stopped taking Vitamin D for a month.) and as “low” as 66. I feel best when my Vitamin D is between 75-80 ng/mL.

Eat your sunscreen

Your body’s ability to activate and process Vitamin D does not happen in a vacuum. Like everything else…how your skin reacts to the sun—whether you burn easily (or not); whether your skin converts sunlight to Vitamin D (or not)—is affected by your food and lifestyle choices. An anti-inflammatory way of eating and living promotes clear skin, boosts immune health and reduces inflammation; it can even potentially protect your skin from sunburn.

Include: Anti-inflammatory whole food choices that promote overall skin health include: high-quality sources of protein (wild-caught fish, grass-fed meats); healthy fats (e.g., avocado, olive oil, walnuts); loads of leafy greens; and foods high in omega-3s (e.g., sardines, anchovies, cod liver oil, chia seeds, etc.). When consumed regularly, foods rich in antioxidants, like Vitamin C and astaxanthin (antioxidants are substances that slow down or prevent damage to cells that are caused by free-radicals, such as getting too much sun) can help protect against UV damage from the inside out: salmon, green tea, berries, watermelon, cruciferous vegetables, ginger and turmeric.

Confused about how to get on an anti-inflammatory eating track?  Jumpstart healthy eating and lifestyle habits with my DIY (or Guided) 7-Day Summer Detox, which focuses on clean eating and de-stressing the body.

Avoid: Foods that create or worsen inflammation in the body: Processed foods. Refined carbohydrates. Grains. Sugar. Industrial seed oils, like corn, canola, soybean, cottonseed, are high in omega 6 and promote inflammation in the body.

A word about sunscreen

Popular commercial sunscreens often contain hormone-disrupting chemicals, like oxybenzone and avobenzone, and may contain other harmful active ingredients.22 According to the Environmental Working Group, a non-profit health and environment research organization, using sunscreen should be a last resort.23 Instead, they advise planning your time in the sun; checking the UV Index; wearing sun-protective clothing (a hat, sunglasses, light-colored shirt and shorts); finding (or making) shade. When you use a sunscreen, you may want to use an EWG-recommended sunscreen based on your needs.

Personally, because I recognize the benefits of regular sun exposure, I take a layered approach to my relationship with the sun. I regularly eat anti-inflammatory whole foods. Even though my skin tends towards olive and tans easily, I always wear sunscreen on my face. I use an all-natural mineral-based physical sunscreen (no chemical hormone-disruptors!). Yes, it is thick, somewhat pasty and white, but I’m fine with this!  If I’m at the beach or pool, I have a big hat and long-sleeved white cover with me at all times. I will sit in the sun (no sunscreen on body) for 15 to 20 minutes for my dose of D. Afterwards, I apply mineral sunscreen to all exposed body parts.  I don’t stay out longer in the sun because I have sunscreen on, and I reapply after going in the water.

Tips for Optimizing Your Vitamin D Levels

1.  Test, don’t guess. Always, always, always test your level of Vitamin D. The test to ask your doctor to run is for Vitamin D3 or 25 (OH) D. Do NOT haphazardly supplement with Vitamin D until you know your Vitamin D status.

2.  Follow an anti-inflammatory eating plan: do this regularly, not just once in a while!

3.  Include anti-oxidant rich foods at every meal.

4.  Don’t be afraid of the sun! Know your skin type and practice safe sun.

5.  Choose a chemical-free sunscreen; a natural, physical sunscreen is best. Always wear sunscreen on your face.

6.  Using sunscreen is not an excuse to stay out longer in the sun.

7.  The following supplements complement an anti-inflammatory eating plan and can help promote overall immune and skin health. Keep in mind: supplements DO NOT replace an anti-inflammatory whole foods-based diet and healthy lifestyle habits.

Vitamin D3 with K2.  Do NOT supplement until you get your Vitamin D level tested and know your current status. Personally, I use 5,000 IU from fall through spring. And about 3,000 IU in the summer.

Vitamin C.  Personally, I take 4,000 mg daily; 1,000 mg daily is a nice maintenance dose.

Magnesium. Helps your body optimize Vitamin D, whether through the sun or through supplementation.24

Omega 3.  An important healthy fat for hormone balance and skin health. Take as recommended.

Astaxanthin. An antioxidant that helps with vision, heart health and skin health. Studies have shown that it can help strengthen the immune system; it is associated with stimulating two components of the immune response (B cell phagocytes and T cell lymphocytes).25  Take as recommended.

Sources and References

Hi, I’m Kathryn Matthews. As a Board Certified Functional Health Coach, I help clients reclaim their energy, vitality and well-being. I want you to feel empowered about taking charge of YOUR health! To learn more, see About Kathryn.

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