We’re living in an era where everything is instant. We can place an online order in the morning and it can be delivered the same day, share prices can peak or tumble in an instant on a tweet sent from the other side of the globe, and information on any subject can be found online at any time. There’s no digging around in the local library or Encyclopaedia Britannica, like when I was a teenager.
From listening to my young people, it also seems that the same attitude in some people is found for other things in life. I’ve heard that there’s no point in going on the oral contraceptive because you can take a pill the morning after to prevent pregnancy. There’s no point in using barrier methods of contraception because you can take tablets to prevent you catching HIV, and there are antibiotics for other sexually transmitted diseases such as gonorrhoea, syphilis and chlamydia. I think I can officially say that my eyes have literally been opened to such behaviours and I feel old and naïve all at the same time.
It now seems that we also now have a tablet treatment for sunburn.
What is it?
An editorial by Professor McGrath in the February 2025 edition of the British Journal of Dermatology discusses the use of single high-dose vitamin D3 as a treatment for sunburn.
[McGrath JA and Lu KQ. Single high-dose vitamin D3: a promising sunburn therapy. Br J Dermatol 2025;192:181-182.]
What treatments are there for sunburn?
Currently we have nothing other than avoidance of the sun, cooling creams and moisturisers, topical steroids and painkillers. These are in an attempt to reduce the redness, swelling, inflammation and skin damage that too much UV exposure causes.
How does high-dose vitamin D3 work?
The large dose of vitamin D3 works by increasing the levels of inactive vitamin D3 in the blood and sunburnt skin which is then converted into the active form by skin cells. This active vitamin D3 then works to promote the production of anti-inflammatory markers in the skin which help to reduce the inflammation caused by sunburn.
[Scott JF, Das LM, Ahsanuddin S et al. Oral vitamin D rapidly attenuates inflammation from sunburn: an interventional study. J Invest Dermatol. 2017;137(10):2078-2086]
In the above study, participants given high doses of vitamin D3 showed a sustained reduction in skin redness as well as less skin damage, reduced expression of inflammatory markers in the skin and up regulation of skin barrier repair genes compared to controls (those not given high dose vitamin D3).
How much vitamin D3 is needed?
In the study by Scott et al, they gave 200,000 IU of vitamin D3 to twenty healthy adults one hour after experimental sunburn.
Is 200,000 IU vitamin D3 safe?
It does sound like a lot. The NHS recommends that everyone should take 400 IU (10 micrograms) per day during the autumn and winter. The NHS also recommends not to take more than 4000 IU (or 100 micrograms) in anyone aged over 11 years of age. For children aged 1-10 years, they should have no more than 2000 IU (50 micrograms) per day. And for babies less than 12 months of age, they should have no more than 1000 IU (25 micrograms) per day.
Moreover, the study by Scott et al did look at toxic levels and if there was any effect on calcium levels in the blood and there were no instances of toxicity or high calcium levels amongst the study participants.
A study in 2023 looked at the safety of high dose vitamin D3 in haemodialysis patients. They gave 23 haemodialysis patients 300,000 IU vitamin D3 orally and monthly for 9 months. They found no evidence of high blood levels of calcium or phosphorus or any events of hypercalcaemia (high calcium levels).
[Guella A, Abduelkarem AR, Hassanein MM. The effects and safety of high dose vitamin D3 in hemodialysis patients. Pharm Pract (Granada). 2023;21(1):2273.]
So can we take high dose vitamin D3 before we get sunburnt to prevent us getting sunburnt?
I think the advice currently is no.
And are you now recommending this as a sunburn treatment?
There is certainly evidence showing its safety at a dose of 100,000 IU. Studies where this dose has been given to patients with acute radiation dermatitis or toxic erythema of chemotherapy caused a rapid improvement in their skin symptoms within 1-7 days with no adverse effects.
[Nguyen CV, Zheng L, Lu KQ. High-dose vitamin D for the management acute radiation dermatitis. JAAD Case rep. 2023;39:47-50]
[Nguyen CV, Zheng L, Zhou XA et al. High-dose Vitamin D for the Management of Toxic Erythema of Chemotherapy in Hospitalized Patients. JAMA Dermatol 2022;159:219-222]
And how often can you take a single high dose of vitamin D3?
Well, that we don’t know. In both of the above studies, the high dose vitamin D3 was given again after 7 days but these are small case reports of 2 and 6 patients respectively.
Clearly larger, more comprehensive studies are required. We don’t know if taking high dose vitamin D3 to prevent sunburn will reduce skin cancer risk in later life. We need to know more about optimal dosages, optimal timings, frequency of ingestion and also the safety aspects before we, as dermatologists can incorporate this into standard clinical advice but it certainly looks promising!
Kind regards,
Sandy
Dr Sandy Flann, Consultant Dermatologist.
