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How much Vitamin D should I be taking daily?

Understanding the importance of Vitamin D and why we should all be taking supplements

ingredients 05 vitamin-D3 illustration
Laura Sugden
Lead Copywriter and Health Coach
February 17, 2021
4 min read

Vitamin D. The ‘sunshine vitamin’. It just sounds healthy, and it is. In fact, it’s one of the most important nutrients there is. There’s all sorts of advice out there for how much you need, how to get it, what works and what doesn’t. It’s a bit tiring (or is that just a sign of low vitamin D?) so we thought we’d put together a guide. 

Why do I need vitamin D?

Vitamin D is involved in so many processes that we can’t list them all here. It’s a true all-rounder, affecting everything from your brain to your toenails. But some of the most important, evidence-based benefits are:

  • Strengthens bones and teeth

  • Lowers risk of macular degeneration

  • Maintains normal cognitive function

  • Enhances the body’s immune system

  • Reduces inflammation around the heart

  • Regulates sodium concentration in the blood

Research also suggests that low levels of vitamin D are linked to obesity, depression, type 2 diabetes, auto-immune diseases and osteoporosis. It’s not something you want to skimp on. 

How to get vitamin D naturally

Everyone knows we make vitamin D from sunlight (the process is called cutaneous synthesis). So that’s fine. No need to worry about it. Of course, it’s not that simple.

Depending on where you live, it’s possible that you aren’t able to make enough vitamin D all year round. In the UK, for example, the NHS recommends that everyone take a supplement between October and March. As lockdowns have forced more people to work from home, we’re getting even less sunshine, making a supplement even more important. On top of that, as we age, our skin cells become less efficient in producing vitamin D.

Now, you can also get vitamin D from your diet, but it’s a struggle. To reach the 10µg a day the NHS recommends, you’d need to eat 10 eggs. Or 7 tablespoons of fortified margarine. Or 800g of beef liver. You get the picture.

So how much Vitamin D do I need?

When you search online, you might find conflicting advice on how much vitamin D you should take. Typically the two numbers thrown around are 10µg and 20µg a day (if you see 400IU and 800IU, those are the same thing—40 International Units are equivalent to 1µg). 

However, the NHS also points out that the upper limit is 100µg a day, so there’s a lot of leeway. For that reason, we’ve put 20µg in each dose of the Smart Supplement, just to make sure you’re covered. 

How to choose a vitamin D supplement?

There are several types of vitamin D. The two you’re likely to see are D2 and D3 (or ergocalciferol and cholecalciferol if you’re being fancy). D2 can be found in certain fungi, and is often chemically synthesised for supplements. Heights uses D3, the most common, which is the type you make when your skin is exposed to sunlight. It’s the biologically active form, and increases blood levels of vitamin D more than D2 does. 

You also need to make sure that any vitamin D you take is absorbable. It’s a fat-soluble nutrient, so unless you take it in conjunction with fat, it will pass right through you. When choosing a supplement, look for one that contains enough fat to allow efficient absorption. Otherwise, you’ll need to make sure you take it with a meal.

The last factor to consider when choosing a supplement is the source of the vitamin D itself. Many people believe that vitamin D3 comes exclusively from animal products, whereas D2 is the type suitable for vegans. This isn’t true.

While lots of supplements will use animal sources for D3 (typically sheep wool), it’s also possible to derive it from plant-based sources. And as it’s more effective than D2, it’s worth seeking out those plant-based supplements if you’re a vegan, rather than settling for D2.

Want to find out more about each ingredient and dose in the Smart Supplement?

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