Vitamin D Deficiency

What is vitamin D?

Vitamin D helps your body absorb calcium and phosphate from food. These minerals are essential for keeping your bones, teeth, and muscles healthy. Without enough vitamin D, you cannot absorb these minerals properly.

Why is vitamin D important?

A lack of vitamin D can cause:

• Rickets in children (soft, weak bones that can become deformed)
• Osteomalacia in adults (bone pain and muscle weakness)
• Tiredness and fatigue
• Muscle aches and general aches and pains

Where do we get vitamin D?

Your body makes vitamin D when your skin is exposed to sunlight. From late March to the end of September, most people in the UK can get enough vitamin D from sunlight.

You can also get vitamin D from:

• Oily fish like salmon, sardines, mackerel, and trout
• Red meat and egg yolks
• Fortified foods like some breakfast cereals and spreads

Who is at risk of deficiency?

Some people don't get enough vitamin D and should take supplements all year round:

• People who are housebound or spend very little time outdoors
• People who cover most of their skin when outside
• People with dark skin (African, African-Caribbean, or South Asian background)
• All children aged 1 to 4 years
• Breastfed babies from birth

How much vitamin D do you need?

Adults and children over 1 year need 10 micrograms of vitamin D daily. During autumn and winter, everyone should consider taking a daily supplement containing 10 micrograms.

Do not take more than 100 micrograms (4,000 IU) per day as this could be harmful.

When to see your GP

See your GP if you have symptoms of vitamin D deficiency such as bone pain, muscle weakness, or fatigue. A blood test can check your vitamin D levels.

Based on NHS information. Last reviewed January 2026.