In this guide
From October to March, sunlight in our region is mostly not strong enough for the skin to make enough vitamin D. The NHS therefore advises adults to consider a vitamin D supplement during these months, but whether you need one and how much depends on local recommendations and the advice of a doctor or pharmacist. Winter tiredness has many causes, so vitamin D is not automatically the explanation. This plan helps you organise your habits and prepare for a talk with your doctor.
Week 1: foods with vitamin D
Only a few foods naturally contain vitamin D. The richest are oily fish such as salmon, sardines, trout, herring and mackerel, with smaller amounts in egg yolks and fortified products.
- Plan oily fish once or twice a week.
- Check the label of cereals, spreads or plant drinks to see whether they are fortified with vitamin D.
- Note how you sleep and feel, so you have something to compare later.
Week 2: daylight and movement
Winter sun makes little vitamin D, but time outdoors has other benefits. A daytime walk supports your sleep rhythm, mood and fitness.
- Get out into daylight every day, ideally around midday, even for a short walk.
- Link the walk to a habit you already have, for example after lunch.
- In snow and in the mountains, still protect your skin and eyes.
Weeks 3 and 4: blood test and a talk with your doctor
Routine testing is not needed for everyone. According to MedlinePlus, a 25(OH)D test usually makes sense with bone pain, muscle weakness, very little sun exposure, conditions that reduce absorption such as coeliac or Crohn's disease, kidney or liver disease, and with some medicines.
- Prepare a list of the medicines and supplements you already take, including multivitamins.
- Ask whether you need a test or whether the general winter advice is enough.
- If a deficiency is confirmed, your doctor sets the dose and duration.
When to be careful
Too much vitamin D almost always comes from supplements, not from the sun. A long-term excess raises calcium in the blood and can damage the kidneys and heart. The upper intake limit depends on local reference values and is neither a target nor a dose to take on your own. Pregnant women, people with kidney stones or kidney disease, and anyone taking medicines should agree the plan with a doctor.
Sources: NHS MedlinePlus.
Common questions
Can I get enough vitamin D from the sun in winter?
Hardly, from October to March. The NHS says sunlight is not strong enough in these months, so food and, on advice, a supplement play a bigger role.
Should I raise my supplement dose if I always feel tired?
No. Tiredness has many causes. Too much vitamin D can raise blood calcium, so a doctor decides on testing and on the dose for treating a deficiency.
Before first use
Choose products for your dietary routine and care needs. Follow a healthcare professional’s advice for diagnosis and treatment of symptoms. Check suitability first during pregnancy and for use by children.
