Vitamin D supplements work better with this simple change, study finds

When do you take your vitamin D?

For many people, it's first thing in the morning, swallowed with a glass of water or a quick coffee before breakfast. Others take it at night, perhaps alongside their other supplements.

But if you've been wondering whether morning or evening is actually better, the answer may have less to do with the clock than with what's on your plate.

The researchers didn't change the supplement or increase the dose. They changed one simple part of the routine instead — and a few months later, the difference showed up in the blood tests.

So what was different?

The meal may matter more than the time

The researchers followed 17 people being treated for vitamin D deficiency who had not been getting their levels up despite taking supplements. They were asked to take the same supplement with the largest meal of the day.

After two to three months, their average blood level of vitamin D had risen by 56.7%. The researchers described this as roughly a 50% increase. That sounds impressive, but there's an important caveat: this was a very small study, and it did not include a control group. It doesn't mean everyone will see their vitamin D level rise by half simply by moving a tablet to dinner.

What it does suggest is that when you take vitamin D with a meal, it can make a difference.

Why the food around it matters

Vitamin D is a fat-soluble vitamin, which means dietary fat plays a role in how the body absorbs it. The British Heart Foundation explains that vitamin D is found naturally in foods including oily fish and egg yolks, as well as some fortified foods.

You don't need to turn your supplement into an excuse for a heavy meal. The practical idea is simply to take it alongside a normal meal rather than swallowing it with a coffee on an empty stomach.

Think eggs, oily fish, yogurt, cheese, avocado or food cooked with a little oil.

So instead of worrying about whether 8 a.m. is better than 8 p.m., taking your tablet with a proper meal may be the more useful habit.

How much vitamin D do you actually need?

This is where the advice varies depending on where you live.

In the UK, the NHS recommends a daily 10-microgram supplement during autumn and winter, when sunlight isn't strong enough for most people to make enough vitamin D. Some people at higher risk are advised to take it throughout the year.

In the Netherlands, the Voedingscentrum recommends 10 micrograms a day for women aged 50 to 70, while women and men aged 70 and over are advised to take 20 micrograms. Men aged 50 to 70 are advised to take 10 micrograms in certain circumstances, such as having darker skin or spending little time outdoors in daylight.

These are general recommendations, not instructions to increase your dose because you think you might be deficient.

So when should you take it?

There isn't a magic vitamin D hour.

If you already take a supplement, the simplest approach is to make it part of a meal you reliably eat, preferably one containing some fat, rather than taking it with a coffee on an empty stomach and hoping for the best.

And don't assume that taking more will give you more benefit. The NHS warns that excessive vitamin D over time can cause harmful calcium buildup, and advises adults not to exceed 100 micrograms a day unless a doctor has recommended otherwise.

The Cleveland Clinic study doesn't prove that dinner is better than breakfast. It points to something more useful: when it comes to vitamin D, what's on the plate may matter more than what's on the clock.