Vitamin D — the one supplement every person in Ireland should be taking. And most people are still getting it wrong.

Studies here show that around 90% of Irish adults have inadequate Vitamin D intake. That’s not a fringe problem — it’s the population norm. And it’s not just a winter issue, though between October and March there is effectively no meaningful UVB reaching Ireland at all.

The best source remains sunlight — but it has to be direct, on bare skin, for at least 15 to 30 minutes a day. Not through glass. Not with sunscreen. Actual skin, actual sun. For much of the year in Ireland, that simply isn’t available.

People of darker-skinned ethnicity have higher Vitamin D requirements because increased melanin reduces the body’s ability to make Vitamin D from sunlight — so if that applies to you, supplementation year-round is particularly important, not just in winter.

The fat-soluble piece matters here. Vitamins D and K are both fat-soluble, which means they require adequate fat digestion to be absorbed properly. If your bile production is sluggish, or your digestive enzymes aren’t working well, you may be supplementing consistently and still not absorbing properly. This is something we look at carefully at Drummartin Clinic.

Why K2 must come with D3. Vitamin D increases calcium absorption — which is largely why we want it. But calcium needs directing to the right places. K2 does that job — routing calcium into bones and teeth rather than soft tissue and arterial walls. Taking high-dose D3 over time without K2 is something I’d be cautious about.

On dosing — official Irish guidelines recommend 600 IU daily for adults. In my clinical experience that is a reasonable starting point but often insufficient to correct established deficiency. Vitamin D is fat-soluble and stored in the body, so it does accumulate — which means more is not always better. Getting your blood level tested is the most sensible approach. Optimal serum levels in clinical practice tend to sit in the range of 80–120 nmol/L. Above 125 or so, you’re getting into territory worth watching.

If someone already has adequate levels and simply wants to maintain them, a practical approach is a somewhat higher dose taken less frequently rather than a modest daily dose. Your clinician can guide what’s right for your situation.

We stock D3+K2 Pro at nutrisense.ie — a combined formula that gets this pairing right.

(General clinical information — not personal medical advice. Testing and dosing decisions are best made with your doctor.)

📍 nutrisense.ie | Drummartin Clinic, Goatstown, Dublin 14