Vitamin D and Sunlight
For many years we have been warned about the dangers of the sun and the risk of skin cancer due to overexposure to the sun’s harmful rays. Given we know that the sun is an abundant source of vitamin D and that it is estimated that approximately 1 in 4 Australian adults are vitamin D deficient, are we doing more harm than good by avoiding the sun?
Let’s first look at vitamin D, it’s benefits and the impact that insufficient levels of vitamin D can have on our health.
What is Vitamin D?
Vitamin D is a fat-soluble vitamin that is stored in the liver and fatty tissues and, unlike most vitamins, can mostly be made by the body (with the help of sunlight). Vitamin D acts as a hormone within the body and works closely with the kidneys in order to keep minerals such as calcium and phosphorus in balance.
Vitamin D also plays an important role in helping your immune system to function and studies now show us that low levels can lead to autoimmunity and increase the chance of infection. Some of the other benefits of Vitamin D include:
- Improved bone health - assists the absorption of calcium and other vitamins and minerals such as magnesium and vitamin K into the bones that contribute to bone health
- Improved immunity - reduces inflammation and prevents against infections and viruses by regulating the role of white blood cells, which decreases the viruses’ ability to reproduce and activates certain enzymes that prevent tissue damage
- Supports healthy cell replication which can protect against the development of autoimmune conditions
- Improved cardiovascular health - assist with the regulation of blood pressure and cholesterol levels
- Stabilised blood sugar levels - works with calcium to regulate insulin secretion
- Improved moods - increased brain function and hormone control (serotonin and melatonin)
- Nitric Oxide production - increased mitochondrial energy
- Improved gut health - studies show a greater microbial diversity in those with adequate levels of vitamin D as well as an integrous gut lining
Now let’s look at the potential health risks that may be associated with vitamin D deficiency:
- Weakened bones - conditions such as osteomalacia (soft bones), rickets and the potential for developing osteoporosis
- Poor immunity - susceptibility to infections and viruses
- Mood disorders - including depression, seasonal affective disorder (SAD), and severe mood problems experienced during PMS, insomnia and anxiety
- Hormone imbalances - low levels of vitamin D can lead to an improper balance of testosterone and estrogen production
- Cognitive/mental health problems - low levels of vitamin D can be associated with poor decision-making skills, inability to focus and even an increased risk for developing schizophrenia and multiple sclerosis
- Increased susceptibility to some cancers (especially breast, colon and prostate cancers) - vitamin D plays a role in factors that influence tumor growth, cell differentiation and apoptosis
Sources of Vitamin D
We get vitamin D from two main sources:
- Food / supplements (cod liver oil, oily fish like tuna, sardines, mackerel and wild caught salmon, pastured eggs, butter, beef liver and certain mushrooms that have been exposed to UV light)
- The SUN!
Every living thing on the planet depends on the sun - plants, bacteria, and mammals! In humans, as our skin absorbs sunlight, it produces vitamin D by converting cholesterol to vitamin D3.
Sunlight has a balanced amount of red, blue and purple light, and, as it hits the receptors in your eyes and skin, signals many beneficial processes in the body. Red light in particular is a healing light that turns off inflammatory pathways in the body. This red light is particularly found in the morning sun, but you can also get it from infrared saunas and even campfires!
Let’s quickly look at the benefits of red light:
- Improves sleep quality
- Increases melatonin production (particularly the morning sun!)
- Promotes the production of hormones such as serotonin and dopamine, which helps to turn off your sympathetic nervous system (and in turn, improve your sleep)
- Stimulates collagen, increases bone healing and heals wounds (think anti-aging - not what we normally associate sun with)
The best time of day to expose yourself to the sunlight is in the mornings, before UVA and UVB rays are fully present. When exposed to the infrared light from the morning sun, it actually preconditions your skin to protect it from the harsher rays that are present later in the day.
There are many studies showing that insufficient sun exposure is an emerging public health problem and that there is a wide range of health benefits to be obtained from the sun and exposure to UV light. It is essential to note here that it is important to be sensible with sun exposure as exposure in the middle of the day for extended periods of time can be very damaging and is certainly not recommended.
My key recommendations when it comes to increasing your levels of vitamin D naturally are to:
- Watch the sunrise and expose your eyes and skin to the infrared light
- Aim to spend at least 10-20 minutes of unexposed time in the sun daily. This depends on a couple of factors such as where you are in the world in relation the equator, the time of year, your melanin (ie darker skin requires longer exposure to sunlight in order to receive the same benefits as some with with fairer skin)
- Include therapies such as red light saunas and camping into your life!
- Include as many of the foods that contain high levels of vitamin D
- Insufficient Sun Exposure Has Become a Real Public Health Problem - https://pubmed.ncbi.nlm.nih.gov/32668607/
- The risks and benefits of sun exposure 2016 - https://pubmed.ncbi.nlm.nih.gov/27942349/