Vitamin D is often called the "sunshine vitamin" — but in Ireland, where sunlight hours are limited for much of the year, deficiency is remarkably common. Estimates suggest that over 40% of Irish adults have insufficient vitamin D levels, rising to 70–80% during winter months. While most people associate vitamin D with bone health, its effects on the skin are increasingly well understood — and for those with certain skin conditions, vitamin D status may be more relevant than they realise.
What is Vitamin D and Why Does Ireland Have a Problem?
Vitamin D is a fat-soluble vitamin that the body produces when UVB rays from sunlight hit the skin. It is unique among vitamins in that food alone rarely provides sufficient amounts — the skin is the primary production site. The problem for Irish people is straightforward: Ireland sits at a latitude where UVB rays are insufficient for vitamin D synthesis for approximately 7 months of the year (October to April). Even during summer, cloud cover, sunscreen use and indoor lifestyles significantly limit production.
The Health Service Executive (HSE) recommends that all Irish adults consider vitamin D supplementation, particularly during autumn and winter. Risk groups who need to be especially vigilant include:
- Older adults (skin becomes less efficient at producing vitamin D with age)
- People with darker skin tones (melanin reduces UVB absorption)
- Those who are housebound or rarely outdoors
- People who cover skin for cultural or medical reasons
- Those with coeliac disease, Crohn's or other conditions affecting fat absorption
Vitamin D and the Skin — What's the Connection?
Vitamin D receptors are present throughout the skin. Vitamin D plays an active role in regulating skin cell growth, immune responses in the skin, and the maintenance of the skin's protective barrier. When vitamin D levels are low, several processes that keep skin healthy can become impaired.
Can Vitamin D Deficiency Cause Hives?
Research has found a consistent association between vitamin D deficiency and chronic urticaria (hives) — the condition where the skin develops itchy, raised red welts. Studies have found that people with chronic urticaria have significantly lower vitamin D levels than those without it. Vitamin D's anti-inflammatory role in the immune system may help regulate the overactive immune responses that trigger hive outbreaks. Several clinical studies have shown that vitamin D supplementation can reduce the severity and frequency of hives in people who are deficient.
Can Vitamin D Deficiency Cause Itchy Skin?
Yes — low vitamin D is associated with dry, itchy skin through its effects on the skin barrier. Vitamin D helps regulate the production of proteins that maintain the skin's moisture barrier (including filaggrin — the same protein implicated in eczema). A deficiency impairs this barrier, increasing transepidermal water loss and causing dryness and itching. Multiple studies have found that eczema patients consistently have lower vitamin D levels, and some trials have shown symptom improvement with supplementation.
Vitamin D and Psoriasis
Psoriasis is a chronic autoimmune skin condition causing rapid skin cell turnover, scaling and red plaques. Vitamin D analogues (synthetic forms of vitamin D) are actually first-line topical treatments for psoriasis — prescribed by dermatologists to slow the excessive skin cell growth that drives the condition. People with psoriasis are significantly more likely to have low vitamin D levels. Oral vitamin D supplementation, while not a treatment for psoriasis, is recommended to correct deficiency in people with the condition.
Vitamin D and Eczema
The association between vitamin D deficiency and eczema (atopic dermatitis) is one of the most studied in dermatology. Multiple reviews have concluded that low vitamin D is more prevalent in people with eczema, and several randomised controlled trials have shown that vitamin D supplementation can reduce eczema severity — particularly in those who are deficient at baseline. In Ireland, where eczema rates are among the highest in Europe and vitamin D deficiency is widespread, correcting vitamin D status is considered important in overall eczema management.
Vitamin D and Acne
Some emerging research suggests that vitamin D's anti-inflammatory properties may be relevant to acne. Inflammation is a key driver of inflammatory acne lesions (papules and pustules), and vitamin D's immune-modulating role could theoretically help reduce severity. The evidence here is less robust than for eczema or psoriasis, but ensuring adequate vitamin D levels as part of a holistic approach to skin health is reasonable.
Vitamin D and Skin Ageing
Vitamin D supports collagen synthesis and skin cell renewal. Deficiency may contribute to accelerated skin ageing, reduced collagen production and impaired wound healing. Maintaining adequate vitamin D is considered an important part of skin health as we age — not a replacement for topical skincare, but a foundation for skin that can function and repair normally.
Signs and Symptoms of Vitamin D Deficiency
Skin problems are rarely the first sign of vitamin D deficiency. More common early symptoms include:
- Fatigue and low energy
- Muscle weakness or aches
- Bone pain or tenderness
- Frequent infections or slow recovery
- Low mood or depression (vitamin D receptors are also present in the brain)
- Hair thinning or loss
Skin problems — dryness, worsening eczema, rashes or slow wound healing — may appear alongside or after these systemic symptoms.
How to Maintain Adequate Vitamin D Levels in Ireland
1. Sunshine (When Available)
From May to September in Ireland, 10–30 minutes of midday sun exposure on the forearms and face (without sunscreen) several times a week can help maintain vitamin D levels. Outside these months, sunlight in Ireland does not contain sufficient UVB rays to produce meaningful amounts of vitamin D regardless of how much time you spend outdoors.
2. Diet
Food sources of vitamin D include oily fish (salmon, mackerel, sardines), egg yolks, liver and fortified foods (some dairy, cereals and plant milks). However, diet alone is rarely sufficient to meet requirements — even a diet rich in these foods typically provides only 20–30% of daily vitamin D needs.
3. Vitamin D Supplements — The Practical Solution for Ireland
Given Ireland's climate, supplementation is the most practical way for most adults to maintain adequate vitamin D year-round. The HSE recommends all adults consider vitamin D supplementation, particularly from October to March.
At Chemco Pharmacy, we stock a range of high-quality vitamin D supplements to suit different preferences:
BetterYou DLux 3000 Vitamin D Oral Spray — a convenient daily oral spray providing 3,000 IU (75mcg) of vitamin D3. The spray format bypasses the digestive system for faster absorption — particularly useful for those with digestive conditions or who find tablets difficult to swallow. One spray per day. Available from Chemco Pharmacy.
Pharma Nord BioActive D-Pearls 75mcg (3,000 IU) — a highly bioavailable vitamin D3 supplement from one of Scandinavia's most trusted supplement manufacturers. The oil-filled capsule format maximises absorption of this fat-soluble vitamin. 80 capsule pack providing an 80-day supply. Available from Chemco Pharmacy.
If you are unsure which dose or format of vitamin D is right for you, speak with your Chemco pharmacist. Those with certain medical conditions or who suspect severe deficiency should have their vitamin D level tested by their GP before starting high-dose supplementation.
Frequently Asked Questions
How long does it take to recover from vitamin D deficiency?
With consistent daily supplementation, vitamin D levels typically improve within 8–12 weeks. For people who are severely deficient, a higher loading dose prescribed by a GP may be recommended initially, followed by a maintenance dose. Blood levels should ideally be rechecked after 3 months of supplementation to confirm they have normalised.
What does a vitamin D rash look like?
There is no single "vitamin D rash" — rather, deficiency can worsen pre-existing skin conditions. People with eczema may notice more frequent flares; those with chronic hives may find outbreaks more frequent or severe; and general skin dryness and roughness can increase. If you develop a new rash, particularly one that does not respond to usual treatment, it is worth discussing your vitamin D status with your GP or pharmacist.
Can too much vitamin D cause skin problems?
Vitamin D toxicity from supplementation is rare but possible with very high doses (typically more than 10,000 IU/day taken for extended periods). Toxicity does not typically cause skin rashes. Standard recommended doses (400–4,000 IU/day) are considered safe for most adults. If you are supplementing at higher doses, discuss this with your pharmacist or GP.
Are vitamin D supplements available in Ireland without a prescription?
Yes. Vitamin D supplements are available without prescription from Chemco Pharmacy. Standard doses of 400–1,000 IU are suitable for general deficiency prevention; doses of 2,000–4,000 IU are commonly used for correction of mild to moderate deficiency. Higher therapeutic doses should be taken under medical supervision.
This article is for informational purposes and is not a substitute for professional medical advice. If you have a skin condition or suspect vitamin D deficiency, speak with your pharmacist or GP.