If there is one supplement that Irish people are particularly advised to consider, it's vitamin D. Ireland's northern latitude and notoriously overcast weather make us one of the most vitamin D–deficient populations in Europe, and the consequences of this deficiency extend well beyond bone health. This guide covers everything you need to know about vitamin D in an Irish context.
Vitamin D is unique among vitamins: the primary way the human body obtains it is not through food, but through sunlight. When UVB rays from the sun hit the skin, they trigger the synthesis of vitamin D3 (cholecalciferol) in the skin cells. This process is efficient — a fair-skinned person can produce adequate vitamin D from about 15–30 minutes of summer sunshine on arms and face.
The problem for Ireland is geographical. At 51–55°N latitude, the angle of the sun's rays from October to March is too low for UVB light to reach the Earth's surface effectively. Even on bright winter days in Cork or Dublin, the sun simply doesn't have sufficient intensity to trigger vitamin D synthesis. This means that for roughly six months of the year, most Irish people cannot produce meaningful amounts of vitamin D from sunlight alone.
Even during summer, cloud cover, time spent indoors, the use of sunscreen (which blocks UVB), and darker skin tones all reduce vitamin D synthesis. The result: surveys consistently show that a significant proportion of Irish adults and children have low or deficient vitamin D levels.
Vitamin D is far more than a "bone vitamin." It functions as a prohormone — once activated, it influences hundreds of genes throughout the body. Key roles include:
The HSE and the FSAI (Food Safety Authority of Ireland) recommend that all adults and children over 12 months take a vitamin D supplement of 10 micrograms (400 IU) daily during autumn and winter. Specific groups — including older adults, pregnant and breastfeeding women, those who cover their skin for religious reasons, and people with darker skin tones — are advised to supplement year-round.
Infants from birth to 12 months are recommended 5 micrograms (200 IU) daily regardless of season, and the HSE specifically advises that breastfed babies receive vitamin D drops from birth.
Vitamin D deficiency often produces no obvious symptoms, which is why it can go undetected. However, some people notice:
The only reliable way to know your vitamin D level is through a blood test (25-hydroxyvitamin D test), which your GP can arrange. Alternatively, private testing is available in some pharmacies and health shops.
Recommended doses vary by age, individual circumstances, and starting level:
Some healthcare providers prescribe higher doses (2000–4000 IU daily) for documented deficiency under medical supervision. The safe upper limit set by the European Food Safety Authority (EFSA) for adults is 100 mcg (4000 IU) daily — doses above this should not be taken without medical advice, as vitamin D toxicity, while rare, is possible with very high supplementation.
Vitamin D supplements come in two forms:
For most people, D3 is the preferred choice. Vegan D3 from lichen is widely available and equally effective to lanolin-derived D3.
There is growing interest in combining vitamin D with vitamin K2. Vitamin D increases calcium absorption, and K2 (particularly as MK-7) helps direct this calcium to bones rather than to soft tissue and arteries. Some healthcare practitioners recommend taking D3 alongside K2, especially at higher doses. Many supplement products now combine both.
While food sources alone are unlikely to provide sufficient vitamin D for most Irish people, they contribute to your overall intake:
Mushrooms exposed to UV light also produce vitamin D2 — you can increase their D content by placing them gill-side up in sunlight for 30–60 minutes before eating.
What to look for:
Browse our range of vitamin D supplements at The Honey Pot Health Store
Shop at The Honey Pot → 📞 052-612 1457