Vitamin D supplementation – how high should you go?

As we head (full tilt) towards winter, it’s that time of year when health experts start reminding us to take a vitamin D supplement.

According to Food Standards Scotland, less than half of adults and children actually do this, despite boundless research showing the importance of vitamin D for bone, muscle health and more.

But how much should you take? Well, that’s the thing doctors and scientists don’t always agree on.

Official advice around D3 dosage

The government advice in the UK is for people to take a daily supplement containing 10 micrograms of vitamin D equivalent to 400 international units (IUs) a day, year-round, to keep our levels up.

But it’s all the more important in winter because our main natural source of vitamin D is sunlight and we all know there’s less of that around between October and March.

In the US, the National Institutes of Health says the average (non-deficient) adult should aim for 600 IUs per day in their diet.

But that advice is aimed at preventing a deficiency in vitamin D which can lead to all sorts of health problems – it’s not designed to help you achieve optimal levels.

During the pandemic multiple studies equated lower levels of vitamin D with poorer outcomes for patients – so much so there were calls for basic foods like milk and bread to be fortified with it.

Scientists call for higher dosing

A global group of scientists who came together to advocate for vitamin D supplementation recommended taking higher levels of vitamin D, 4000IUs (100 micrograms – 10 times the minimum recommended UK dose) a day, than currently recommended by health officials.

The National Health Service in the UK warns that excessive levels of vitamin D could be harmful and they advise not to exceed more than 4,000 IUs a day so that amount is regarded to be the highest dose within safer parameters.

I’ve found that supplementing with higher doses of vitamin D in winter generally means I don’t suffer as badly from Seasonal Affective Disorder which used to absolutely thump me come January each year.

Despite sitting in front of a light box I still got it really bad and it affected everything from my mood to my energy levels, to even my skin and the way I looked.

A vitamin D rapid test available inexpensively from pharmacies.
A vitamin D rapid test kit available from pharmacies.

Why D3 and K2 go together

So what I tend to do with dosing now is play it by ear and usually average around 2500IUs a day in winter.

You can now buy Rapid Vitamin D test kits inexpensively in pharmacies which will show you whether you’re deficient, have insufficient, sufficient or excess levels that can help guide your intake.

Dr Brad Stanfield, a primary care physician with a YouTube channel focusing on preventative medicine, recommends taking 1000 IUs a day which seems like a reasonable compromise between the different approaches to supplementation.

You want to make sure your vitamin supplement contains D3, the form that ensures that calcium is absorbed easily, and taking vitamin K2 alongside it helps activate the protein, osteocalcin, which integrates calcium into our bone so that’s why you often see them together.

Vitamin D helps your skin too!

And if the anti-inflammatory, immuno and bone supporting health benefits aren’t enough, vitamin D also plays an important role in skin protecting against inflammatory skin conditions like acne and psoriasis.

It helps regulate the function of our skin cells including the rate that they turn over, and acts as an antioxidant protecting against environmental and sun damage and all this in turn protects against premature aging of our skin.

So there is every reason to supplement, in my view – especially in winter.

And if you can it’s always a good idea to discuss supplementation with a medical professional, particularly if you have any health conditions.

I take the vitamin D3 capsule with K2 and magnesium from DoNotAge. You can get 10% off all DoNotAge supplements, including Omega 3, using code HONEST.

I use affiliate links where possible on this website and on my YouTube channel. It means I make a small amount of commission on any sales made as a result of someone using one of my links and/or code. This helps to support my work. Thank you!