Why Vitamin D Deficiency Is a Growing UK Concern

Vitamin D is essential for supporting immune function, bone health, muscle strength, and general wellbeing. But despite its importance, a large proportion of the UK population has low vitamin D levels — especially during the colder months when sunlight is limited. In 2025, awareness around vitamin D deficiency continues to rise as more people seek safe ways to maintain their levels year-round.

In the UK, sunlight is only strong enough to trigger natural vitamin D production from April to September, and even then, it depends on skin type, time outdoors, age, and location. Public Health England recommends all adults take a daily supplement during autumn and winter — and some people may benefit from taking one all year round.

📌 According to the UK Scientific Advisory Committee on Nutrition (SACN), around 20% of adults have low vitamin D levels during winter and spring.

Common Signs of Low Vitamin D

Vitamin D deficiency doesn’t always cause clear symptoms at first, but over time it may affect how you feel. People with low levels often report:

• Fatigue or low energy
• Muscle weakness or poor recovery
• Low mood or winter blues
• Frequent colds or infections
• Difficulty concentrating

In more severe cases, vitamin D deficiency has been associated with bone softening conditions such as osteomalacia in adults or rickets in children. ➡️ The NHS highlights its role in calcium regulation and bone health.

Who’s Most at Risk in the UK?

Some people are more likely to have low vitamin D levels, even during summer. You may be at greater risk if you:

• Spend most of your time indoors due to work or mobility
• Wear clothing that covers most of your skin outdoors (for cultural, religious, or climate reasons)
• Have darker skin (e.g., African, Caribbean, South Asian backgrounds), which naturally filters UVB rays more
• Are pregnant or breastfeeding
• Are over 65, as ageing reduces skin’s ability to produce vitamin D
• Are vegan or vegetarian with limited intake of fortified foods and fatty fish

NICE guidelines recommend supplements for people in these risk groups, especially if they receive little sunlight exposure.

Even if you're not in a high-risk group, UK government guidance still recommends that everyone considers a supplement, especially in autumn and winter.

Can You Get Enough Vitamin D from Sunlight?

In the UK, UVB rays required for vitamin D production are only strong enough between late March and early September. Just 10–20 minutes of midday sun exposure a few times a week may be sufficient — but only if you’re outdoors, and not behind glass.

Learn more: Vitamin D from Sunlight in the UK

➡️ According to Bupa, supplements are essential during winter months when sun exposure is too weak to maintain healthy levels.

Daily Supplementation: How Much Vitamin D Do You Need?

The NHS recommends that everyone aged 4 and over considers taking 10 micrograms (400 IU) of vitamin D per day from October to March. However, some individuals — especially those at risk of deficiency — may benefit from higher doses, such as 1000 IU to 5000 IU daily.

For example, if you have darker skin, are pregnant, or have minimal sunlight exposure, a daily dose of 4000 IU is considered safe for long-term use under EU and UK guidelines.

💡 Doses above 4000 IU per day are not recommended without medical supervision, as excessive intake could lead to vitamin D toxicity (rare, but possible). It’s important to follow label guidance or consult a healthcare professional.

🩺 The Endocrine Society and EFSA (European Food Safety Authority) both recognise 4000 IU per day as the tolerable upper limit for healthy adults, unless under medical care.

For those interested in higher-strength support with additional benefits, we’ve created a detailed article:
👉 Vitamin D3 5000 IU + K2: Benefits Explained

Choosing a Quality Vitamin D Supplement

When selecting a supplement, look for:

• ✅ Vitamin D3 (cholecalciferol) — better absorbed than D2
• ✅ GMP-certified, UK-made formula
• ✅ Combined with Vitamin K2 (MK-7) for bone health synergy
• ✅ Oil-based or taken with food for optimal absorption

🟡 Shop Vitamin D3 5000 IU + K2
🟡 Shop Vitamin D3 4000 IU + K2 + Zinc + Magnesium

In 2025, vitamin D remains a vital part of everyday wellness in the UK — particularly as more people experience low levels due to indoor lifestyles and limited sunlight. By understanding the causes, symptoms, and solutions for deficiency, you can take control of your health and support your bones, immunity, and energy year-round.

📌 For official NHS guidance, visit: NHS Vitamin D page