Why a Leading Dermatologist Is Questioning the SPF Mantra
For anyone serious about slowing down skin ageing, daily SPF has long been non-negotiable. Dermatologists have championed it, skincare experts have endorsed it, and the message has been drilled into public consciousness with near-religious fervour. Yet there is a growing sense among some medical professionals that the pendulum may have swung too far.
Dr Stefanie Williams, Dermatologist and founder of Eudelo Dermatology & Skin Wellbeing, has noticed a troubling trend in her clinic. Parents who have applied broad-spectrum sun protection on their children every single day, year round, practically from birth. While the intention is protective, the reality may be causing unintended harm.
The Vitamin D Dilemma
The concern centres on vitamin D, a nutrient essential for both physical and mental health. Research has linked adequate vitamin D levels to stronger immunity against flu, colds and COVID, while deficiency has been associated with increased symptoms of depression and anxiety. Some studies even suggest potential protective effects against certain cancers.
Here lies the crux of the problem: in the UK, between 80 and 90 percent of natural vitamin D is derived from sun exposure. Both excessive sun avoidance and diligent daily use of broad-spectrum sun protection can significantly impact the body’s ability to produce this vital nutrient.
‘I often measure vitamin D levels in my patients,’ Dr Stefanie notes, ‘and almost always they come back as too low.’
What Counts as ‘Too Low’?
The goalposts for optimal vitamin D have shifted over the years. Labs once flagged anything under 50 nanomoles per litre as insufficient. Most now recommend aiming for above 75 nanomoles per litre, while some experts advocate for levels as high as 100 or even 120. Going above 200 to 250 nanomoles per litre, however, is inadvisable. For those reading US lab reports, the conversion is straightforward: 50 nanomoles per litre equals 20 nanograms per millilitre.
Striking the Right Balance
None of this is to suggest that sun protection should be abandoned. Far from it. For anyone committed to preserving their skin’s youthful appearance, daily SPF remains an important tool in the anti-ageing arsenal. The issue is one of perspective and proportion.
Dr Stefanie’ advice is refreshingly sensible. There is no need to develop what she calls ‘sunphobia’, an almost pathological fear of any sun exposure whatsoever. Burning the skin is certainly to be avoided, but cowering from every ray of daylight does vitamin D levels no favours.
The Supplement Solution
The practical solution? A vitamin D3 supplement. These are readily available over the counter from health food shops and pharmacies. The dose matters though. Most multivitamins contain around 400 units of D3, which is simply not enough for most people.
Dr Stefanie recommends at least 1,000 to 2,000 units daily. Going up to 4,000 units per day is perfectly safe without needing to check blood levels first. Some doctors suggest calculating the dose at 1,000 units per 15 kilograms of body weight for more personalised guidance.
For those who want to be precise, a blood test can determine current levels and allow for tailored supplementation. Dr Stefanie herself takes 8,000 units daily to maintain her blood level above 100 nanomoles per litre, demonstrating that requirements vary considerably from person to person.
The Bottom Line
Daily SPF still earns its place in any serious skincare routine aimed at slowing the visible signs of ageing. Yet it should be paired with a sensible vitamin D3 supplement and a measured approach to sun exposure. The sun does offer genuine benefits for the skin, a nuance that has been somewhat lost amid decades of well-meaning but increasingly extreme sun avoidance messaging.
As with so much in life, the answer lies not in extremes but in balance. Protect the skin, yes. But not at the cost of overall health and wellbeing.
Whether you have a medical skin condition which needs treatment or simply want to look your very best, our specialised dermatology team will help you achieve the very best result.
