Frequently Asked Questions
What is Vitamin D?
Vitamin D is often called the 'sunshine vitamin' because it's synthesised in the skin following exposure to sunlight, and it's unusual in that our bodies can both manufacture and store it. It plays several important roles in the maintenance of good health, contributing to normal immune function, muscle function, and the maintenance of normal bones and teeth.
What is Vitamin D good for?
Vitamin D supports far more than bones. It contributes to the maintenance of normal bones and teeth, normal muscle function, the normal function of the immune system, and normal blood calcium levels. That combination is why it's one of the most widely taken supplements in the UK - a single nutrient quietly supporting several of the body's most important systems.
Do I need to take Vitamin D in the UK?
For a good part of the year, yes. In the UK between October and early March, we simply don't get enough sunlight for the skin to make vitamin D, making synthesis almost impossible during winter. That's why government nutrition advisers recommend adults consider a daily 10 microgram (400iu) vitamin D supplement, and why so many of us take one year-round as an easy insurance policy.
What's the difference between Vitamin D2 and Vitamin D3?
They're two forms of the same vitamin, but they're not equal. Vitamin D3 is the form naturally produced by your own body when skin meets sunlight, and it's considered the more beneficial form - which is why our entire range, from 400iu through to Super Strength 4000iu, uses vitamin D3.
Which Vitamin D supplement is right for me?
Match the strength to your needs and life stage. Vitamin D3 400iu covers the everyday level in line with government guidance a sensible year-round baseline. Step up to 1000iu through autumn and winter, when UK sunlight can't do the job, or choose Super Strength 4000iu if you want maximum support. If bone health is the priority, our D3 4000iu + K2 combination pairs the two key bone nutrients in one tablet, while Osteo4 goes further still, combining calcium, vitamin D, K and magnesium at 100% NRV. Whatever the strength, every formula uses D3 the form your body makes naturally.
Can you get enough Vitamin D from food alone?
It's genuinely difficult - vitamin D occurs naturally in only a handful of foods, such as oily fish and egg yolks, and the average British diet isn't conducive to a high intake. Sunlight is our main source, and with British weather being what it is, a daily supplement is the most reliable way to keep your levels topped up, particularly from autumn to spring.
Should I take Vitamin D with Vitamin K?
They make a sensible pairing, which is why we offer a Super Strength Vitamin D3 4000iu + K2 100mcg combination tablet. Vitamin D helps your body absorb calcium and supports normal blood calcium levels, while vitamin K contributes to the maintenance of normal bones - so many people like to take the two together as part of a bone health routine, alongside calcium and magnesium (all four feature in our Osteo4 formula).
When is the best time to take Vitamin D?
With a meal is ideal - vitamin D is fat-soluble, so a little dietary fat helps your body absorb it properly. Most people take theirs with breakfast so it becomes part of the daily routine. As with most nutrients, consistency matters far more than the exact hour you take it.
Why shop for Vitamin D supplements at Just Vitamins?
We cover the full strength spectrum 400iu, 1000iu and Super Strength 4000iu so you can match your vitamin D precisely to your needs and the season, with every strength clearly stated as both iu and NRV on the label. The entire range uses vitamin D3, the body's preferred natural form, and we offer smart combinations for bone health too: D3 + K2 in one tablet, and Osteo4 with all four key bone nutrients. All formulated to strict GMP standards in the UK.