From October 1, people across the UK are advised to take a daily vitamin D supplement. The advice comes as part of an annual public health push to prevent widespread winter deficiencies.
Why October 1 is the turning point
From October 1 until late March, sunlight levels across the UK drop significantly. The human body naturally produces vitamin D when bare skin is exposed to direct sunlight. However, during the autumn and winter months, the sun sits too low in the sky, and its rays are not strong enough to trigger this natural process.
Health specialists are issuing reminders to the public to monitor their vitamin D intake and take supplements as needed. Nutritionist Brittany Miles shared a message on social media, explaining: "Your annual vitamin D reminder. The days are getting shorter, we’re spending less time outside, and that means less opportunity for our bodies to make vitamin D from sunlight."
Similarly, on the NHS website, the health service says: "From about late March or early April to the end of September, most people should be able to make all the vitamin D they need from sunlight. The body creates vitamin D from direct sunlight on the skin when outdoors. But between October and early March, we do not make enough vitamin D from sunlight."
Official guidance and recommended dosage
On Gov.uk, a statement from Public Health England and National Institute for Health and Care Excellence explains the importance of vitamin D supplementation during winter. It says: "When outdoors during the spring and summer, most people make enough vitamin D from sunlight on the skin, but in the UK between October and early March, we can’t make vitamin D from sunlight because the sun is too low in the sky. Because it’s difficult to get enough vitamin D from food, it’s best to take a vitamin D supplement during the autumn and winter."
Because it is incredibly difficult to get enough vitamin D from dietary sources alone, such as oily fish, eggs, and fortified spreads, health experts advise a daily winter supplement to bridge the gap.
The national health guidance states that everyone aged four and older should consider taking a daily 10-microgram supplement, which is equivalent to 400 International Units (IU). Maintaining adequate levels of vitamin D is essential for several reasons:
- Bone and muscle health
- Immunity
- Deficiency prevention
- General well-being
It regulates the levels of calcium and phosphate in the body, which helps keep bones, teeth, and muscles healthy. It supports a healthy immune system during the peak season for winter colds and flu.
Regular intake prevents conditions like rickets in children and bone pain or muscle weakness in adults. Emerging research also links adequate levels to mood regulation and overall metabolic health.
Cost and availability of supplements
Inexpensive daily tablets or drops are widely available at local pharmacies and supermarkets. However, it is important to speak to your GP first before taking any new supplements, to ensure they are suitable for you. Low-income families may also be eligible to receive free vitamins through government-backed Healthy Start schemes.
There are many vitamin D supplements available at supermarkets, chemists and wellbeing retailers. For instance, Boots is selling a bottle of Vitamin D 10 µg Food Supplement for £2.75. The bottle contains 90 tablets, which equate to 3p per pill.
Taking more is not automatically better, however. NHS guidance says adults should not take more than 100 micrograms a day unless a doctor has recommended a different amount. Taking too much over a long period can cause calcium to build up in the body, potentially weakening bones and damaging the kidneys and heart.
Food sources and those needing year-round protection
What foods contain vitamin D?
- Oily fish – such as salmon, sardines, trout, herring or mackerel
- Red meat
- Egg yolks
- Fortified foods – such as some fat spreads and breakfast cereals
- Liver (avoid liver if you're pregnant)
While the general population is advised to supplement during the colder months, certain groups are at a higher risk of severe deficiency. Health experts recommend that some people take a daily supplement all year round:
People with limited sun exposure. This includes anyone who spends most of their day indoors, residents of care homes, or people who wear clothing that covers most of their skin when outside.
People with darker skin tones, such as those of African, African-Caribbean, or South Asian descent. They do not manufacture vitamin D as efficiently from UK sunlight and require year-round support.
Infants and toddlers. Breastfed babies from birth to one year old should have a daily supplement of 8.5 to 10 micrograms, while children aged one to four require 10 micrograms daily throughout the entire year.
