More about Vitamin D and Sun Protection! Whats in it for me?
SolarD sunscreen was introduced into the Australian market in late 2014, advertised as being a technologically advanced formula that permits the particular wavelengths of ultra-violet light that your body uses to naturally produce vitamin D. The concept for this product is new and no doubt of interest to consumers with the increasing concerns over their vitamin D levels and reports that regular sunscreens prevent vitamin D production. Without suggesting that people should avoid using SolarD, I do feel that it should be used with caution and appropriate consideration for their sunscreen needs, lifestyle and the recommendation of their doctor.
Importance of vitamin D
Vitamin D, as with all vitamins are essential to our health, vitamin D helps the absorbtion of minerals including; calcium, iron, magnesium, phosphate and zinc, all of which are critical to bone health. Being deficient in vitamin D can cause rickets, osteomalacia and osteoporosis and has been linked to cancer, various auto-immune, cardiovascular disease and mental health.
The recommended daily amount (RDA) of vitamin D for adults who do not have a vitamin D deficiency is 600IU, this is equivalent to 0.0000015g (15µg).
Sources of vitamin D
There are two types of vitamin D, D2 and D3; vitamin D2 is found in mushrooms and ‘fortified foods’ such as milk, margarine and breakfast cereals where the vitamins have been artificially added. Sources of vitamin D3 include foods such as salmon and other oily fish, eggs and milk in addition to fortified foods and vitamin D supplements, vitamin D is also produced through sun exposure.
Vitamin D3 is the most potent and effective type of vitamin D with sun exposure being the most efficient means of attaining our vitamin D3.The most concentrated dietary source of vitamin D is found in wild salmon which has up to 1000IU of vitamin D3 in every 100g. Turns out that a salmon a day could keep the vitamin D deficiency away, unfortunately, eating salmon everyday is not great for a balanced diet, which is why sun exposure is important.
Vitamin D3 and sun exposure
Producing vitamin D3 through sun exposure is a complex reaction that occurs within our skin, requiring sun light to drive the reaction, specifically the wavelengths of light between 270 and 320nm. Visible light are those wavelengths between 390-700nm, as the wavelengths of light required to produce vitamin D3 are below those of the visible, they are ‘ultra-violet’ (UV) wavelengths which we can call UV light.
The amount of vitamin D3 produced when exposing ourselves to sun light will vary considerably with the amount of exposed skin, age, height, skin color, time of day, season, longitude and altitude, from as little as a few minutes in summer, to a few hours in winter. Interestingly, the amount of vitamin D generated in the skin is limited, to the point where longer exposure to sun light will not necessarily increase our vitamin D levels, unlike the risk of skin damage and skin cancer which will increase the longer we spend in the sun.
Causes of sunburn and the vitamin D paradox
Ultra-violet B (UVB) light refers to those wavelengths of light between 280 and 315nm, Ultra-violet A (UVA) are those wavelengths between 315 and 390nm. The UVB wavelengths are most responsible for causing sunburn, but are also responsible for causing skin cancer and other sun damage, particularly premature ageing such as wrinkles and sun spots. The method used to test the sun protection factor (SPF) of a product uses sunburn as the endpoint to determine whether the product is providing protection simply because the sunburn is an indicator of sun damage that is (close to) immediately visible and easily measured.
You may now note that the wavelengths of light that are required to produce of vitamin D3 detailed above are the same as those that cause sunburn. A sunscreen that is aimed to prevent sunburn and that is promoted to permit the particular UVB light that your body uses to naturally produce vitamin D3 should be physically impossible.
A look at how Solar D works
The UV absorbtion spectrum of SolarD SPF50 sunscreen in comparison to a regular SPF50+ Sunscreen (below) shows SolarD absorbs less light in the UVB (280 – 315nm) region than a standard sunscreen, which goes to justify the claim that SolarD permits the particular UVB light that produce vitamin D3, but doesn’t necessarily support the SPF50 claim.
How does SolarD make sun protection claims if there isn’t enough UVB absorbtion to prevent sunburn?
Before I go into any further detail and to place the remainder of this article in context, I must highlight that I am not aware of SolarD’s technology or formulation so I do not know with any certainty how SolarD achieves their claims. Being involved in the development of sunscreens (as I am) and having been aware of the health issues surrounding vitamin D, I had already considered ways that a sunscreen can promote vitamin D production and protect against sunburn, they are unusual and in my mind, not necessarily in the consumers best interest.
Sunburn is only one symptom of sun exposure, it is the one we readily relate to as we see and feel it so soon after we have been in the sun, other symptoms include skin cancer and premature ageing such as wrinkles and sun spots. We often treat sunburn using after sun products containing anti-inflammatory ingredients such as aloe vera and green tea and also anaesthetics like lidocaine, but these products won’t undo the damage that has already been caused, only reduce the redness/pain we can see and feel.
A sunscreen could, in theory, have a high sun protection factor (SPF) without the need for the product to absorb a lot of UV light by treating the visible symptoms of sun exposure we know as sunburn. A product such as this would be reliant on those same anti-inflammatory ingredients used in after sun products to compensate for a reduction in UV absorbance relative to that of a normal sunscreen. The issue here is that by failing to absorb as much UV light, more damaging UV light will be allowed to pass through to the skin where damage will occur despite the sunburn having been masked by the ant-inflammatory action. We could liken this to spraining your ankle whilst on pain and anti-inflammatory medication, the damage was done, the ankle is now weak and unstable, we just can’t feel it and in no way was the damage prevented.
I am not suggesting that this is how SolarD functions, without seeing the product technology in its entirety; this is only my theory on how the product may perform and something worth being mindful of.
Vitamin D production vs sun protection
The primary purpose for any sunscreen is to minimize sun damage by absorbing the UV light and reducing the risks of sunburn, skin cancer and premature ageing when we’re out in the sun. Realizing that sunscreens have an obvious potential to alter the way vitamin D3 is formed and influence vitamin D deficiency and related diseases, we need to instill a balanced approach so that we get enough sun exposure to allow vitamin D production, but not so much as to cause sun damage.
While wearing a regular SPF50+ sunscreen in summer will slow the formation of vitamin D3, the small amount of UV light which does pass through over the period of a few hours will generate the same amount of vitamin D3 as spending a few minutes without sunscreen with the added benefit of their being less risk of damaging the skin and there have been studies that show this to be the case.
We should all use sunscreen whenever there is a risk of sunburn, if there is no risk of sunburn, there is no need to wear sunscreen, if in doubt though, your best to have sunscreen on. If you’re going to be outdoors outside peak sunburn times (early morning or late afternoon) or only for very short periods during the day, there is no need to apply sunscreen, by doing so, our bodies will be produce vitamin D3. For those who have concerns relating to premature ageing such as wrinkles and sun spints and prefer to wear sunscreen at all times, then SolarD may be a good option to minimize damage without inhibiting vitamin D too much, a lower SPF sunscreen would however have a similar effect.
For those who are planning on spending a lot of time in the sun, especially at the beach, pool or playing sport, your best to wear a 4 hour water resistant SPF50+ sunscreen for maximum protection, remembering the sunscreen will allow vitamin D3 to be formed. I stress this point because SolarD, being a 2 hour water resistant SPF50 sunscreen has 15-20% less SPF and half the water resistance of a 4 hour water resistant SPF50+ which is not going to provide the best protection.
To buy SolarD or not to buy SolarD
I don’t want to discourage people from using SolarD, it’s an interesting concept that will have a place on the market, however it does complicate the decision making process, particularly for those who believe their existing sunscreen is somehow less effective in terms of allowing vitamin D production to occur.
If you haven’t been diagnosed with a vitamin D deficiency, then your current lifestyle and existing sunscreen habits are working for you, there is no need for a product like SolarD. For those who have been diagnosed with a vitamin D deficiency, your doctor would offer the best solution with consideration for minor lifestyle changes to get more sun, using vitamin D supplements and perhaps recommend SolarD.
Olds, 2010; Elucidating the Links Between UV Radiation and Vitamin D Synthesis; Using an In Vitro Model, Queensland University of Technology.
Research & Development Manager
Development chemist / Expertise with Sunscreen Technology