Everything you need to know about vitamin D

Vitamin D, often called the “sunlight vitamin,” is one of the most important nutrients for maintaining overall health and wellbeing. Our bodies naturally produce it when our skin is exposed to sunlight, but many of us still don’t get enough - whether due to lifestyle, location, or simply spending more time indoors. This is why vitamin D supplementation has become so important for supporting key functions in the body, including a strong immune system, steady energy levels, and long-term wellness. Among the different forms, vitamin D3 stands out as the most active and effective option for giving your body the support it needs every day of the year.

Why Vitamin D Matters

Vitamin D is an essential nutrient that supports multiple functions in the body. Most people know it for its role in maintaining healthy bones and teeth, but its benefits extend far beyond that. Research has shown that vitamin D helps regulate the immune system, supports cardiovascular health, and even plays a role in mood balance.

When it comes to energy, vitamin D works at a cellular level to help convert food into usable fuel for the body. Low vitamin D levels are often linked to fatigue, low mood, and increased susceptibility to seasonal illnesses. This is why keeping your vitamin D levels topped up, especially as we enter the darker, colder months, is so important.

Why vitamin D3 is the superior form

Not all vitamin D is created equal. The two main forms of vitamin D are D2 (ergocalciferol) and D3 (cholecalciferol). While both can increase vitamin D levels in the blood, vitamin D3 is the most active and effective form for the body.

Here’s why:

• Better absorption: Studies show that vitamin D3 is more efficiently absorbed than D2.

• Longer-lasting effects: Vitamin D3 raises and maintains vitamin D levels in the bloodstream for longer periods.

• Closer to nature: Vitamin D3 is the form of vitamin D our bodies naturally produce when exposed to sunlight, making it more biologically active.

Choosing a supplement with vitamin D3 means your body gets the most effective support for immunity, energy, and overall wellness.

Immunity and energy support through the seasons

As summer fades into autumn and winter, our exposure to sunlight decreases significantly. This seasonal change often coincides with a rise in coughs, common colds, and general fatigue. That’s because reduced vitamin D levels can leave the immune system less equipped to fend off infections.

Vitamin D3 plays a direct role in activating immune cells that help fight off viruses and bacteria. At the same time, it supports mitochondrial function - the “powerhouses” of our cells - which helps sustain energy and reduce feelings of tiredness. Simply put, vitamin D3 acts as both a shield and an energy booster, keeping you resilient when your body needs it most.

Why supplement all year round?

While it’s tempting to think vitamin D is only necessary in winter, the truth is that supplementing immune-boosting nutrients all year round provides consistent support for your body. Even in summer, lifestyle factors such as working indoors, using sunscreen, or living in northern climates can limit sun exposure and reduce natural vitamin D production.

That’s why building a foundation of key nutrients, including vitamin D3, helps keep your immune system strong and your energy levels balanced no matter the season. However, as autumn approaches and seasonal bugs become more prevalent, supplementing becomes even more essential.

A natural  boost with Immunity+

At Doctor Seaweed, we believe in prevention and proactive wellness. That’s why we created Immunity+, our award-winning supplement designed to help you feel your best all year round.

Immunity+ combines:

• Organic Scottish seaweed - a natural source of iodine and antioxidants.

• Vitamin D3 - the superior form of vitamin D for strong immunity and energy.

• Vitamin B12 - essential for red blood cell formation and combating tiredness.

Together, this powerful blend supports your immune system, boosts energy, and promotes overall wellness. As we move into the colder months, Immunity+ is your daily defence against seasonal challenges. Prevention is always better than cure - and giving your body the right nutrients is the best place to start. Click here to shop our award-winning Immunity+ supplement.