Sunny Holiday or Vitamin D Supplement? What a Trip Can and Cannot Do
A week of sun feels like a cure for a dark winter, and it does help. But vitamin D does not work like a battery you charge once. Here is what a trip can and cannot do.
Updated 2026-10-07. Education and wellness only, not medical advice.
What a sunny holiday can do
Your skin makes vitamin D when UVB hits it. In strong sun a short midday session can make a full dose, and your body can store some vitamin D in body fat during sunny months. A holiday in the right place and month can therefore build a reserve for darker months, and it is far more effective than the same week in a northern winter. Which months and places suit you is exactly what the Sun Atlas map shows.
What it cannot do
- The store runs down. In one study, people with no UV light at all (submarine crews) lost about half of their vitamin D in two months.
- Living somewhere sunny is no guarantee. A study of 729 adults in Recife, Brazil, where the sun is strong all year, found that 31% still had low vitamin D.
- It depends on you. Age, skin colour, clothing, sunscreen, weight, time outdoors and some medicines all change how much you make.
Who needs extra care
Older people, people who spend little time outdoors, people living far from the equator in winter, people with darker skin, people with overweight or obesity, people who always cover up, and people with gut, liver or kidney disease or on some medicines (such as some anti-seizure drugs) are at higher risk of too little. A blood test is the only way to know your level. Read the full explainer and vitamin D after 60.
A sensible way to think about it
- Use sun as one source, together with food (oily fish, egg yolk, fortified foods) and, where your doctor advises, a supplement.
- Do not take more than recommended: too much from supplements can raise the calcium in your blood. More is not automatically better.
- Choose the trip for the sun and the climate: best winter sun, or check a month on the monthly rankings.
- Keep sessions short and never burn. See sun safety on a vitamin D holiday.
A sunny holiday can help you build a reserve for darker months, but it does not replace a supplement if your doctor recommends one. This page is for education and wellness only and is not medical advice.
More guides
- Can You Get Vitamin D From the Sun in Winter in Europe?
- UV Index 2.5 Explained: Why It Is the Line for Vitamin D
- How Long in the Sun for Vitamin D? By Skin Type and Age
- Vitamin D After 60: How Age Changes What the Sun Gives You
- Best Winter Sun for Vitamin D: Where to Go From November to March
- Best Places for Vitamin D in Spring, Summer, Autumn and Winter
- Sun Safety on a Vitamin D Holiday: Get the Dose, Skip the Burn