Is A Lack of Sunshine Harmful to Your Health?

Sunshine is vital to your health because of Vitamin D. It is estimated that 80% of people in northern countries and over 50% of the world’s population are deficient in this essential nutrient.  Being stuck indoors, especially during winter months, is thought to lead to higher incidences of the diseases linked to low vitamin D levels. 

So, let’s chat about this important Sunshine Vitamin

I’ve been wanting to chat with you about vitamin D ever since I started this blog.  But, as with most things in my life, I was distracted by shiny objects such as running and food.  If you are a regular reader of my blog, you probably noticed that I love to talk about running and food.  Besides my family, those are my two greatest loves. 

But, I had every intention to talk with you about vitamin D because it is vital to our health and well being.  Not many people understand how important this vitamin is.  I felt a need to help spread the word.

Wow, there are entire conferences devoted to the Sunshine Vitamin?

A few years ago, I had the opportunity to attend a conference devoted to this vitamin.  Yes, they actually held an entire conference just for one vitamin. Incredible, right?  In fact, there are many conferences and organizations devoted to the sunshine vitamin.  If anything, that tells me just how important this nutrient is to our health. 

And now, as I write this post, most of the world is in quarantine or self-isolation.  We are stuck in our homes and only allowed to go outdoors, in the sun, for essential purposes.  How will the lack of sunshine impact our health, I wonder?  So, now is the time for me to talk with you about vitamin D.

What is the Sunshine Vitamin?

Vitamin D is often referred to as the Sunshine Vitamin.  This is because you can make all the vitamin D you need to stay healthy from exposure to sunlight.  There are some foods that contain vitamin D as well.  However, these are foods that are not common in the North American diet. 

There are two forms of vitamin D.  Plants, essentially mushrooms, make Vitamin D2.  Animals, including people, make Vitamin D3.  You don’t use the plant form of the sun vitamin very well.  Vegans need to be especially aware of this fact. 

How do you make Vitamin D from the Sun?

When your skin is exposed to the sun, the ultraviolet light (UVB) causes a chain of chemical events that changes cholesterol to vitamin D3.  This compound isn’t ready to do its job just yet. 

Vitamin D3, whether from sun or food, needs to be processed by your liver and  kidney before it becomes active. 

Is a Lack of Sunshine Harmful to Your Health?

What does Vitamin D do?

Once active, Vitamin D circulates back around to your intestines, where it helps you absorb both calcium and phosphorus.  Without the sun vitamin, you would get less than 15% of calcium and 60% of phosphorus from your diet.

Vitamin D helps you keep the right amount of calcium and phosphorus in your blood so that you can stay healthy.  It helps keep your bones strong and your immune system healthy.  Your brain, nervous system, lungs and heart can’t function at their best without the sun vitamin.  You also need vitamin D to help you regulate your blood sugars and insulin levels.  It is also important for controlling your body weight. 

What happens if you don’t get enough vitamin D?

As I said earlier, before now, when we were living routine and normal lives, 50% of the world’s population were estimated to be deficient of vitamin D.  That is a lot of people.   It affects all ages, all genders and all ethnicities equally.  It has been referred to as a pandemic.  And this is why there is so much interest in the vitamin.  And why there are entire conferences devoted to it.  It is a public health issue. 

“This pandemic of hypovitaminosis D can mainly be attributed to lifestyle (for example, reduced outdoor activities) and environmental (for example, air pollution) factors that reduce exposure to sunlight ” – Vitamin D: The “sunshine” vitamin in the Journal of Pharmacology & Pharmacotherapeutics

What diseases are linked to Vitamin D deficiency?


Rickets is the classic diagnosis of a vitamin D deficiency.  This is a disease, mainly in children, with symptoms of soft bones.  These children generally have bone pain, deformed limbs and stunted growth.  In first world countries, this is rarely seen any more. 

But, for the rest of us adults, vitamin D deficiency has more subtle signs.  It is difficult to pin-point vitamin D as a definitive cause in some of these issues.  But science suggests that there is a correlation. 

Let’s look at some of these now.

Weakened Immune System

Vitamin D is important for cellular immunity.  This means that low levels of vitamin D leave you open to more infections.  You may find yourself getting flus and colds more often.  In people with low levels of the sun vitamin, these illnesses can progress to more severe symptoms, such as bronchitis and pneumonia. 

Chronic Fatigue

Low levels of the sun vitamin leave you tired and lack energy.  There is a strong correlation between lower vitamin D levels and reported fatigue, especially in night-time shift workers.

High Blood Pressure and Heart Disease

The sunshine vitamin protects heart cells from inflammation.  It also helps to maintain normal blood pressure.   

Multiple Sclerosis

The closer to the equator, the less cases of multiple sclerosis (MS) there are.  MS attacks also occur more frequently in the wintertime, when there is less sunlight.  So, scientists looked to see if vitamin D was a risk factor.  The result of many studies was that people with MS have lower levels of vitamin D, in general, and need more to help with treatments.   

Bone Pain

This is a symptom of rickets.  But it can also occur in adults without bone deformities.  Back pain is especially prevalent in adults with low vitamin D levels.

Thyroid Disease

The sunshine vitamin also has a role in healthy thyroid metabolism.  Thyroid disorders, especially autoimmune thyroid disease, have been linked to lower levels of vitamin D. 


Numerous studies have demonstrated that sunshine is good for your mental health.  And certainly, vitamin D is a contributing factor in depression. 


Vitamin D is involved in your body’s ability to absorb, use and store calcium.  Low levels of vitamin D can lead to a loss of bone density, which is called osteoporosis.  This can lead to weakened bones that can break easily in elderly adults.


The sun vitamin is involved in insulin secretion and controlling blood sugar.  Lower levels of vitamin D have been linked to insulin resistance and diabetes. 


Research shows a strong link between low vitamin D levels and some types of cancer, especially breast cancer. It is estimated that as many as 75% of cancer patients have low vitamin D levels. 

There is a great deal of research occurring in this area to see if vitamin D supplements can prevent cancer.  However, scientists have not determined if this is a coincidence or if there is a cause-and-effect relationship.

So, how do you ensure you are getting enough vitamin D? 

For the average adult, the recommended daily dose of vitamin D is 400-800 IU per day.  However, some experts think that this should be higher, especially for people who don’t get much sunlight.  If you live in areas where sunlight is limited, you may need more.  Some studies suggest that 1000 – 4000 IU vitamin D per day is better for health for those at risk and living in Northern climates. 

Be sure to ask your doctor how much vitamin D you should be getting

This is a complex question

It is also important to point out that the problems mentioned may not necessarily be from not getting enough.  There are other factors involved, like not being able to absorb vitamin D from foods, having problems making your own from sunlight and drugs that prevent proper vitamin D activity.  

Remember I said there were entire conferences on this sun vitamin.  It is a very complicated subject.  So, please talk to your doctor about your specific needs.

Is a Lack of Sunshine Harmful to Your Health?

How much sunlight should you get in a day?

This is a tricky question.  The same sun rays that help you make vitamin D also increase risk for skin cancer. 

We know that sunscreens can filter out harmful effects of ultraviolet radiation to reduce risk of cancer.  But 30 SPF sunscreen has also been shown to reduce vitamin D production by as much as 95% in some studies.  So, getting enough sunlight to provide vitamin D while reducing your risk of skin cancer will be a balancing act. 

Scientists tell us that if you went outside in full mid-day sunshine, when UVB is at the most intense levels, you would make around 10,000 – 20,000 IU of vitamin D in 30 minutes.  But, you don’t want to be outside in this intense sunshine for too long, since you are also increasing your risk for skin cancers.

The good news is that you don’t need this much vitamin D anyways.  So, going outside when the sun is less intense for 10 – 30 minutes is more than adequate to get your daily dose of the sunshine vitamin. 

What foods contain Vitamin D?

There aren’t many foods that contain vitamin D.  Fatty fish, such as salmon and tuna, contain some vitamin D.  This vitamin has also been added to milk for many decades to help prevent rickets in children.  And some cereals are also fortified with vitamin D.

Here are some foods and their approximate vitamin D levels       

  • Salmon   525 – 980 IU/100g
  • Tuna   260 IU/ 100 g
  • Mackerel  290 – 1000 IU/100g
  • Herring   165 IU/100g
  • Sardines   175 IU/100g
  • Cod liver oil   450 IU per tsp
  • Cows Milk (fortified) 115 – 130 IU/cup
  • Soy Milk (fortified)  100 – 115 IU/cup
  • Orange Juice (fortified)  100 IU/cup
  • Beef liver  50 IU / 100 g
  • Egg yolk   37 IU per yolk
  • Cereals (fortified) 50 – 140 IU/half cup
Is a Lack of Sunshine Harmful to Your Health?

Should you take a Vitamin D supplement?

The discussion to take a vitamin D supplement should be between you and your doctor.  It is always best to consider a supplement based on your current health status and tested blood levels.  Medications you may be taking can interfere with vitamin D, as well. 

However, most experts agree that it is generally safe to take 400 – 1000 IU per day of vitamin D3 for most adults.  Doses as high as 4,000 IU per day are also deemed safe for those with low blood levels or diseases that are known to benefit from supplementation. 

It is always better to get vitamin D from natural sources, such as foods and sunlight, however.  There are some studies that suggest supplements are not doing such a great job.  In recent randomized studies in 2019, there was no significant benefit found to supplementing vitamin D for cancer, diabetes, heart or lung disease.  More research is needed. 

If you do need to supplement, look for vitamin D3.  Our bodies absorb and use Vitamin D3 more easily than any other form. 

Can you get too much Vitamin D?

Vitamin D is a fat-soluble vitamin.  That means that if you take too much, you cannot get rid of the excess easily.  Instead, your body will squirrel away excess into your fat.  So, it is possible to get too much.

But, luckily, getting too much vitamin D is rare.  It is usually caused from people that are mega-dosing. Toxic doses are in the range of 60,000 IU/day and it takes several months to start showing signs of toxicity.  These signs include nausea, headache, weakness and frequent urination.  Too much vitamin D can also lead to kidney stones. 

Try to get outside for 10 – 30 minutes a day

So, as you can see, it is important for you to get outside for some sunshine.  Whether it be in the wintertime or if you are sheltering in place, try to get outdoors in the sun for just 10 to 30 minutes per day, if you can. 

Be sure to keep a safe social distance. Stay in your own yard or on your balcony. Open a sunny window, if you have no other option. Closed windows filter out the necessary UVB rays. Or you can also eat vitamin D rich foods. Just be sure to get some vitamin D and stay healthy.

Be sure to check out the Pink Ribbon Runner Blog for more great articles on staying healthy! I recently wrote about 10 Foods that Boost Your Immune System and 15 Fabulous Ways to Stay Active Indoors.


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  1. Wow thanks for posting this! Super educational. That first graphic explaining how the body uses Vit D was a nice treat. 🙂

  2. Great post! I’ve been aware of the health benefits of Vitamin D, and have used it to fend off the flu as well as just maintain general health, for years. But I didn’t know all of this. Very useful information! Especially the part about how we can’t use plant-based vitamin D well. Thank you so much for sharing! 😊💜

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