News & Advice

Vitamin D Deficiency. It’s not just about bones.

Low Vitamin D levels have been linked to a wide range of health issues, including:

• Cardiovascular disease
• Type 2 diabetes
• Mental health conditions
• Autoimmune disorders such as rheumatoid arthritis and multiple sclerosis
• Dementia
• Osteomalacia (and rickets in children)
• Muscle weakness
• Increased frequency and severity of respiratory infections

Why Is Vitamin D So Important?

Vitamin D is often associated with calcium absorption and bone health, but its role goes much further than that.

It behaves more like a hormone than a vitamin, helping to regulate genes involved in:

• Immune system function
• Brain health
• Inflammation control

This is why deficiency can have such wide-ranging effects on the body.

What Causes Vitamin D Deficiency?

In the UK, Vitamin D deficiency is defined as blood levels below 25 nmol/L (25-hydroxy Vitamin D).

There are several reasons why people become deficient, including:

• Limited sunlight exposure (especially October to March)
• Poor dietary intake
• Higher body fat levels
• Ageing
• Genetics
• Darker skin tones
• Regular use of high-factor sunscreen

For many people, it’s not just one factor, it’s a combination.

How to Improve Your Vitamin D Levels

The good news is that improving your Vitamin D levels is relatively simple once you know how.

1. Get Safe Sun Exposure (April – September)

During the lighter months, sunlight is your best source.

Spending just 10–15 minutes outdoors between 11am and 3pm can generate approximately 1000–2000 IU of Vitamin D.

This happens when UVB rays interact with cholesterol in your skin to produce Vitamin D.

For best results:
• Expose areas like your arms, legs or face
• Avoid sunscreen during this short window only
• Take care not to burn

People with darker skin may need 25–40 minutes of exposure, as increased pigmentation reduces the rate of Vitamin D production.

2. Focus on Diet (October – March)

During the winter months, the sun simply isn’t strong enough in the UK to stimulate Vitamin D production.

This means your diet becomes more important.

Good sources include:

• Oily fish (salmon, mackerel, sardines)
• Egg yolks
• Fortified foods (such as cereals and wholegrain products)

3. Consider Supplementation

For many people, especially in winter, supplementation is a practical solution.

Daily doses of up to 4000 IU of Vitamin D3 are generally considered safe for adults.

If you’re unsure, it’s always best to speak with a healthcare professional before starting.

4. Maintain a Healthy Body Composition

Vitamin D is a fat-soluble vitamin, meaning it can be stored in body fat.

Higher levels of body fat can reduce how much Vitamin D is actively circulating in the bloodstream.

This is why regular exercise is important.

A combination of:
• Aerobic exercise
• Strength training

can help improve body composition and support overall Vitamin D function in the body.

The Bottom Line

Vitamin D plays a far bigger role in your health than most people realise.

From immune function to muscle strength and mental wellbeing, maintaining healthy levels is essential, especially in the UK where deficiency is so common.

Small changes like getting outside more, improving your diet, and considering supplementation can make a meaningful difference.

If you would like any advice, you can ask our experts a question any time you wish, here.