SunFit VITAMIN D AND THE SUNSHINE ‘D’-LEMMA

1- HOW IMPORTANT IS VITAMIN D FOR HEALTH?

‘If you want to grow up to be strong, you have to drink your milk.’ That is how we all learned at a young age the importance of calcium and supplemented vitamin D in the growth and maintenance of healthy bones and strong teeth. Vitamin D is actually what makes it possible to absorb and utilize calcium in the body.

Bones are like a bank account— by eating and consuming calcium, we insert ‘deposits’ that provide strength and density to the skeleton. When needed, the body can make calcium 'withdrawals' by carrying it into the bloodstream to regulate normal body functions.

You can think of vitamin D as the bank manager that tightly controls the deposit and withdrawal processes. Together, calcium and vitamin D form a vital duo for maintaining healthy bones. A deficiency in vitamin D can deplete the bank account (bones) from calcium and lead to their softening and weakening. This is known as ‘rickets’ in children and ‘osteomalacia’ in adults.

But did you know that vitamin D has other hidden talents? More recently, it has been established that sufficient levels of vitamin D could be associated with the prevention of various diseases such as cardiovascular diseases, autoimmune diseases, and cancer.

That being said, getting enough vitamin D can impact your health in many ways.

2- WHERE TO GET VITAMIN D?

Sunshine, diet, and supplementation.

First, you can generate your own vitamin D. The ‘D’-IY way. The skin is the most significant vitamin D factory in our body. It produces vitamin D when exposed to the sun's ultraviolet (UV) rays. Hence, it is often referred to as the ‘sunshine vitamin.’

UV-B light from the sun strikes the skin. Like a game of dominoes, a chain of reaction, converts a substance present in our skin (7-DHC) into vitamin D. The kidneys and liver support this game with some ‘encouragement’ to activate vitamin D into the form used by our body known as calcitriol or vitamin D3.

Our body can also ‘stock’ some vitamin D to store it for 1-2 months by accumulating it in our tissues, which can then be put back into circulation as needed. That is why most people will not become vitamin D deficient even when they lack sun exposure during the winter months.

However, if sunshine does not satisfy your ‘D’-mands, supplements, and food sources can provide alternative ways to help fill up your ‘D’-ficiency.

3- DO ALL SKIN TYPES MAKE THE SAME AMOUNT OF VITAMIN D?

No. Vitamin D production differs for each of us.

Simply put, the lighter the skin type, the higher the amount of vitamin D produced by the body, and the lower the amount of sun needed. Melanin, the pigment that gives the skin its color, acts as a ‘bodyguard’ against UV-B rays making it harder to kick-start the body's vitamin D production. Consequently, individuals with darker skin produce less vitamin D even with the same amount of sunlight exposed.

Age can also influence vitamin D levels. As the years go by, fewer compounds necessary for the production of vitamin D are present in the skin, making it harder for our skin to make this sunshine vitamin. Thus, for the same dose of sun exposure, the elderly produce less vitamin D than younger individuals.

Being overweight may also affect the availability of vitamin D. Body fat will store most of the vitamin D produced by the skin making it less available for the body to use. Therefore, having a body mass index (BMI) of 30 or more is correlated with vitamin D deficiency.

4- HOW LONG SHOULD WE IDEALLY BE EXPOSED TO THE SUN TO PRODUCE ENOUGH VITAMIN D?

You don't have to spend hours in the sun to get enough vitamin D.

In moderate amounts, sun exposure is essential for maintaining our vitamin D levels. We are talking minutes of sun exposure just on the hands and feet. However, excessive exposure can lead to several health risks, such as skin cancer accelerated skin aging and fragility, hence why a delicate balance must be maintained. During the spring and summer months, people soak up sufficient sunlight every day by simply going about their daily routines. Extending their sun exposure does not provide significant benefits and is outweighed by the increased risk of sunburn, early skin aging, and more importantly, skin cancer.

‘All tanning represents damage to the skin.’ There is no such thing as a healthy tan!

Vitamin D is well metabolized before the skin turns to a pink/red colour. When the skin absorbs ultraviolet radiation, it attacks your skin cells’ genetic material (DNA). The damaged skin then becomes a breeding ground for skin cancer.

To keep the sun a pleasure, it is crucial to remember to protect yourself from it during all outdoor activities, whether at the beach, in your garden, on a patio, playing sports, or just going for walks.

You can do this by:

Going outdoors for short periods (5-20 mins)
Not staying outdoors during peak UV hours (UV index equal to or higher than 3)
Wearing protective clothing, sunglasses, and a hat outdoors.
Applying sunscreen with an SPF of 30 or higher, and reapplying frequently.

The tan might be appealing, but once it's gone, the damage left behind persists. Unprotected sunbathing for vitamin D just doesn't pay off.

5- DOES SUNSCREEN CAUSE A VITAMIN D DEFICIENCY?

This sunscreen controversy has its hot flashes but it heats up the most during summer. There have been claims that the leading cause of vitamin D deficiency is the regular use of sunscreens and lack of sunshine exposure; this is not the case. Using daily sunscreen does not cause vitamin D deficiency. People who use sunscreen daily can still maintain their vitamin D levels.

No matter how much sunscreen you apply, some of the sun's ultraviolet rays will always reach your skin in summer months. SPF 30 sunscreens block about 97% of the sun's rays. Those with higher SPF block slightly more, but no sunscreen can stop all of the sun's rays.

Therefore, you can use high protection and still satisfy your vitamin D needs.

6- WHAT IS THE BEST WAY TO APPLY SUNSCREEN?

Apply generous amounts of sunscreen to dry skin.
Reapply sunscreen based on activity level.
Apply sunscreen 15 minutes before going outdoors.
Use sunscreen on skin surfaces that will be exposed to the sun (face, neck, feet, ears, and head.)
Because UV rays can pass through clouds, use sunscreen even when it's cloudy.
Check the expiration date of the sunscreen.

Wear sunscreen year-round, but don't let any product give you a false sense of protection from sun exposure. A combination of shade, clothing, sunscreen, and common sense is your best option.

7- DOES SUN EXPOSURE ALONE PROVIDE ENOUGH VITAMIN D?

You must do these few things if you want to get all the vitamin D from the sun year round. First, make sure you live close to the equator during the warmest time of the year to get the best rays. Then, stay outside for 10 to 15 minutes every few days between 11 am and 3 pm. With all that, you need to make sure to use sunscreen, and avoid sunburn.

Sounds complicated? Not only does it seem impossible for any Canadian, but it comes with many health risks and complications.

Despite being called the ‘sunshine vitamin’, in Canada sunlight alone is insufficient to meet our body’s vitamin D needs, especially during the winter months.

What appears troubling is that Vitamin D synthesis varies considerably based on several external factors such as:

Solar intensity (UV index)
Latitude
Area of skin surface exposed
Cloudiness

In Canada, between October and April, factors like high latitudes, cloudy skies, and shorter days cause the body's vitamin D levels to decrease. “Even if someone stands nearly naked on a rooftop in Montreal during the months of October to March the sun is simply not strong enough to drive the synthesis of vitamin D”, explains Dr. Litvinov, Director of Dermatology Research at McGill University. There are just not enough strong UV rays for the body to make this vitamin! Therefore, it is evident that we have to rely on food sources and supplements for vitamin D.

8- HOW SHOULD WE GET ENOUGH VITAMIN D IN THE WINTER?

Fortunately, getting enough vitamin D is more accessible than most people would think.

Vitamin D in food is rare, but undoubtedly present. Few natural foods contain a significant amount of vitamin D.

Among these foods;

Fatty fish (salmon, tuna, and sardines).
Beef liver
Egg yolk

In Canada, margarine, infant formula, milk, and egg products are fortified with vitamin D. Some yogurts also contain vitamin D if made with fortified milk. You can also take a vitamin D supplement.

Vitamin D supplementation is safe, cost-effective and comes in a variety of forms such as liquid, capsules, jellies, and tablets. You will surely find one that is suitable for you.

Read the labels carefully and watch out for excess vitamin D, which can lead to side effects such as muscle weakness, vomiting, nausea, headache, and bone pain.

9- HOW MUCH VITAMIN D SHOULD WE TAKE FOR OPTIMAL HEALTH?

The recommendation for healthy adults is 400 to 1,000 IU per day, with higher doses recommended for adults over 50 and young adults at risk for osteoporosis or disorders that may affect the absorption of vitamin D.

If you are over 50, Osteoporosis Canada recommends that you receive 800 IU -2000 IU of vitamin D every day.

If you think you lack vitamin D, ask a healthcare professional if you need to take supplements and what would be the appropriate dose for you.

10- WHO IS MOST AT RISK OF A VITAMIN D DEFICIENCY?

Some people are at a higher risk of vitamin D deficiency and are encouraged to consult their doctor to determine if they require vitamin D supplementation. Some examples include:

Being over the age of 50
Having dark skin
Having a BMI over 30
Having a metabolic disorder (such as diabetes)
Having a fat malabsorption disorder
Infants who are exclusively breastfed

AND THE FINAL ‘D’-CISION TO OUR SUNSHINE ‘D’-LEMMA?

Despite the contradictory messages, you and I need to take a vitamin D supplement and complement our diets with foods rich in vitamin D such as milk and salmon, especially in the fall and winter seasons. It is also essential to limit your time in the sun to protect your skin against early wrinkles, damage, skin cancer, and all the dark sides of sun exposure.