Vitamin D is often called the “sunlight vitamin” because our bodies can make it when skin is exposed to the sun. However, here in the UK, especially during autumn and winter, sunlight alone isn’t always enough. That’s why vitamin D deficiency is so common—and why knowing about vitamin D foods, supplements, and safe intake levels is so important.
As a doctor, an extremely common request we get from patients is to have their vitamin D checked, and very often the tests advise that people need to take vitamin D supplements.
Why Vitamin D Is Important
Vitamin D helps regulate calcium and phosphate, keeping bones, teeth, and muscles healthy. Low vitamin D can cause bone pain, muscle weakness, and in severe cases, rickets in children or osteomalacia in adults. It’s also linked with overall immune health.
Types of Vitamin D
There are two main forms:
- Vitamin D3 (cholecalciferol): Found in animal foods and made in the skin after sunlight exposure. This is the form most often used in a vitamin D3 supplement.
- Vitamin D2 (ergocalciferol): Found in some plant foods and mushrooms. Less effective at raising vitamin D levels compared to cholecalciferol.
Best Food Sources of Vitamin D
Getting enough vitamin D from food alone can be tricky, but here are some foods rich in vitamin D:
- Oily fish (salmon, sardines, mackerel, trout) – try not to deep fry fish (I don’t want you to become unhealthy)
- Red meat
- Egg yolks – eggs are a superfood, checkout my blog post on them.
- Liver
- Fortified foods (breakfast cereals, plant-based milks, and some spreads)
- Mushrooms (a plant source containing ergocalciferol)
If you’re looking for foods high in vitamin D, oily fish and fortified foods are some of the best options. We often see patients of south Asian background, and many of their diets are pure vegetarian (no meat, fish or eggs). This makes it harder to recommend vitamin D rich foods, however, fortified foods can be a great way of boosting levels.
Who Needs a Vitamin D Supplement?
Because of the UK climate, the NHS recommends that everyone considers a daily vitamin D supplement from October to March. A typical over-the-counter dose is 800–1000 IU per day.
People with darker skin may need supplements year-round, as their skin needs more sunlight to make enough vitamin D. I often explain to patients how sunlight is used by our skin to create vitamin D, and that in the UK, there is usually not enough sunlight. Therefore, it is important to take a daily supplement, especially in darker months.
One of the ways I like to naturally get vitamin D is through exercising outdoors. I usually wear shorts and T shirt to make sure my arms and legs get enough light. When the sun is bright or UV index is high, be sure to protect your skin with sunscreen.
What are the symptoms of low Vitamin D?
Most people with low vitamin D don’t notice any symptoms at first. But even mild, long-term deficiency can affect calcium balance in the body, leading to overactivity of the parathyroid glands (responsible for controlling calcium levels). This raises the risk of osteoporosis (weak bones), falls, and fractures—especially in older adults.
If vitamin D deficiency becomes severe or prolonged, people may experience bone pain, joint aches, muscle weakness, fatigue, or even muscle twitches. In children, vitamin D deficiency can cause irritability, tiredness, delayed development, bone changes, and sometimes fractures. It is not common that I see this severe level of deficiency in the UK, and when I notice levels are very low, I provide a rapid replacement (high) dose to patients. This usually gets the levels up to range within 7 weeks. After these 7 weeks, I advise patients to continue a daily vitamin D dose of 800-1000 units.
Can You Get Too Much Vitamin D?
Yes. Taking very high doses over a long period can cause problems such as kidney damage and high calcium levels in the blood. That’s why it’s important not to exceed the recommended dose unless prescribed by a doctor. Sometimes patients who are not well informed about the risks get private high dose vitamin D injections done abroad. This is risky, so please be careful, as in some countries, they issue private injections without checking your blood tests and clinical need (I have also seen this being done with vitamin B12 injections).
Other Important Notes
- Some studies suggest a link between vitamin D and mood, though evidence is still developing.
- Vitamin B6 and other nutrients also play a role in energy and metabolism, but they don’t replace the unique role of vitamin D.
Final Thoughts
Vitamin D is vital for bone and muscle health, and in the UK most of us will need a vitamin D3 supplement, especially in the colder months. A diet rich in vitamin D foods can help, but often it’s not enough by itself. My advise would be to visit your local pharmacy and find a daily vitamin D supplement, especially as the daylight hours begin to reduce this autumn/winter.
If you have any other tips or questions, feel free to comment below.
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