You can increase your vitamin D intake through supplements, food and safe exposure to sunlight. The right approach depends on the season and whether you have a diagnosed deficiency.
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How to increase your vitamin D levels
Start with a routine you can maintain: include vitamin D-containing foods, follow UK seasonal supplement advice and ask your GP about persistent symptoms or a confirmed low blood-test result. A food supplement can support your daily intake; treating a deficiency may need a separate plan.
Why vitamin D matters
Vitamin D is vital for the absorption of calcium and phosphorus from the diet, making it essential for healthy bones and teeth. It also contributes to normal muscle function and the normal function of the immune system.
Ways to support your vitamin D levels at a glance
| Approach | What to do | How it helps |
|---|---|---|
| Daily supplement | Follow the label and UK seasonal advice. | Provides a measured amount of vitamin D. |
| Vitamin D-containing foods | Include oily fish, egg yolks or fortified foods. | Adds vitamin D as part of a balanced diet. |
| Safe summer sunlight | Spend time outdoors while protecting your skin. | Helps your skin make vitamin D when sunlight is strong enough. |
| Treatment for confirmed deficiency | Follow the dose and follow-up advised by your clinician. | Corrects low levels with an individual treatment plan. |
1. Consider a vitamin D supplement
There are two types available: vitamin D2 (ergocalciferol) and vitamin D3 (colecalciferol). D3 is the same form made by the body when it is exposed to sunlight.
For adults, NHS advice is to consider 10mcg (400 IU) daily in autumn and winter. People who spend little time outdoors, cover most of their skin or have dark skin should consider taking it throughout the year.1
Compare strengths and formats in the Healthspan Vitamin D range. Follow the label and check your total intake if you use more than one supplement. Food supplements should not replace a varied, balanced diet and healthy lifestyle.
2. Include vitamin D-containing foods
Eating eggs is a useful way to get vitamin D into your diet: the yolks contain it. Oily fish, including salmon, mackerel, herring and sardines, also contributes to your intake. Some cereals, spreads and plant-based drinks have vitamin D added; check their labels. Ordinary cows’ milk in the UK is generally not fortified with vitamin D.1
3. Make use of sunlight safely
Your skin makes vitamin D from direct sunlight outdoors. In the UK, sunlight is not strong enough for adequate production during autumn and winter. There is no single exposure time that suits everyone: skin colour, clothing and the season all affect how much you make. Avoid burning and protect your skin during prolonged exposure.
4. Get advice if you may be deficient
Bone pain or muscle weakness, such as finding stairs or getting out of a chair harder, can be signs of osteomalacia, a condition involving soft bones in adults. These symptoms can have other causes. Speak to your GP if they persist; they can assess you and decide whether tests are needed.5
Read our guide to vitamin D deficiency symptoms for more detail.
If you have a confirmed deficiency, your doctor may prescribe a short course of higher-dose vitamin D followed by a maintenance dose. Do not try to reproduce a prescribed course by taking extra shop-bought tablets.3
How long does it take to raise vitamin D levels?
Vitamin D does not work immediately. Your starting level, dose and health affect the response. Symptoms linked to low vitamin D may improve over a few weeks or months as levels return to normal. Your clinician will advise on the treatment period and any follow-up.2
Can lightbox therapy increase vitamin D?
Light therapy may be used for seasonal affective disorder (SAD), but a SAD lamp should be UV-free. It does not replace a source of vitamin D. Speak to your GP before trying one.4
