So how much sun do we need?

So we need sun exposure for vitamin D, but isn’t sun exposure dangerous?

We have all been told that sun exposure is dangerous, that it causes skin cancer, and that it should be avoided. However, we have also been told that sun exposure allows vitamin D production, and that is very beneficial to our health.

Confused? You are not alone!

So which is it?

Is sun exposure good or bad?

Well, it is both.

It all depends on the dose of sun exposure. And getting the balance right can be hard. Fortunately, there are some simple guidelines out there, to help us construct our lifestyle to get the benefits of sunlight while reducing the harms.

What are the potential harms of sun exposure?

Overexposure to UV radiation from the sun can cause sunburn, skin damage and skin cancer. It also increases our risk of certain eye diseases including cataracts. 

Australia has one of the highest rates of skin cancer in the world. Each year almost 2,000 Aussies die from this largely preventable disease.

Sun exposure is thought to be the cause of 99% of non-melanoma skin cancers, and 95% of melanoma skin cancer (the least common but most dangerous skin cancer).

What are the benefits of sun exposure?

Sun exposure on our skin allows the generation of vitamin D. Vitamin D is essential for a range of functions within our body.

What is vitamin D and why do we need it?

Vitamin D acts as both a vitamin and a hormone. It is essential for absorbing calcium and phosphorus, and for building good bone health. Vitamin D is called a ‘vitamin’ because we get (at least some of) it from our diet in foods like fatty fish, egg yolks and liver. However, we get most of our vitamin D from sunlight exposure. 

Vitamin D is essential for more than just our bone health. Laboratory studies have shown that vitamin D can reduce cancer cell growth, help control infections, and reduce inflammation. Many of our body’s organs and tissues have receptors for vitamin D, and its role in disease prevention and management are ongoing targets of scientific study. Vitamin D is being looked at as a potential treatment for respiratory tract infections, including COVID-19.

Vitamin D deficiency has been associated with a host of chronic illnesses.

Although the topic is one of ongoing research, it is likely that having adequate vitamin D may protect again the following conditions: heart disease and high blood pressure, type 2 diabetes, infections and immune system disease, some types of cancer (including colon, prostate and breast cancer), falls in the elderly, and multiple sclerosis.

It is important to maintain vitamin D above 50mnol/L.

Obesity and vitamin D

People with obesity are at an increased risk of vitamin D deficiency, although it is not completely clear why. It might be due to the vitamin D (which is a fat soluble vitamin) being diluted throughout a person’s fat stores, in a process called ‘volumetric dilution’. In other words, the vitamin D is sequestered away in the stored fat and is not available in the blood to do its good work. People with obesity are considered at high risk of vitamin D deficiency. 

Remember, if you have obesity it is not your fault! Being overweight is due to an imbalance in metabolic hormones caused by our modern lifestyle and mismatched genetics. A low carb real food diet is a fantastic way to sustainably lose weight and reclaim your health forever. For more information check out our program here: https://www.rlmedicine.com/LCL.

So, we don’t want skin cancer because that is bad, and we don’t want vitamin D deficiency, because that is bad too.

Here is what the experts have to say about healthy sun exposure. I like these guidelines and follow them as best I can. 

Safe sun exposure guidelines for most people

If you are not in a high risk group - this general advice can be applied to your lifestyle. More details on these guidelines can be found here: https://www.cancer.org.au/cancer-information/causes-and-prevention/sun-safety/vitamin-d.

Avoid getting burnt! There is general agreement that sunburn (as well as causing pain and embarrassment) is a risk factor for skin cancers, including melanoma. 

Sun protection is recommended when the UV Index is 3 or above, or when spending extended periods of time outdoors.

In some southern areas of Australia, there are times of the year when sun protection may not be necessary, generally late autumn and winter. If you live in an area where the UV Index falls below 3 during these months, you do not require sun protection, unless you are at high altitudes or near highly reflective surfaces like snow, work outdoors, or are outside for extended periods.

In northern areas of Australia, UV radiation is generally higher than in southern areas. Therefore in some parts of the country, sun protection is needed all year round, specifically whenever the UV Index is 3 or higher. In these areas, it is safe to go outside without sun protection in the early morning and late afternoon, when the UV Index falls below 3.

To check UV levels and the times sun protection is required, look at the UV index in whichever weather report you use.

Certain high risk groups may need more vitamin D

If you are in one of these high risk groups (see below) for vitamin D deficiency, you can still follow the sun exposure guidelines as above. However you may need additional vitamin D through supplementation. Also, people who really can’t get enough sunlight exposure because of their lifestyle may fall into this group as well. It is important to see your doctor about getting your vitamin D tested (note that the cost of this test may not be covered by Medicare), and get vitamin D supplements if you are low.

• Those with previous skin cancer, or at high risk of skin cancer
• People who wear covering/concealing clothing
• Naturally very dark-skinned people
• People who spend long hours indoors, including housebound or institutionalised Australians
• Older adults
• People with obesity
• Babies and infants of vitamin D deficient mothers

A note on supplements - vitamin D toxicity is a thing and we advise if you are taking supplements, be sure to mention it to your doctor. It may be prudent to get your levels tested.

With a little bit of planning and thought, we can get the benefits of sun exposure and avoid the harms. Extra points awarded for doing something fun and active when you get your regular sunlight dose, so that you can use your time outside to support your wellbeing in multiple ways. 

Enjoy the sunshine!