How do vitamins and minerals work together?

10 (3 reviews) Rate this page


Emma Thornton
Qualified Nutritionist (BSc, MSc, RNutr)
@EmmaThornton
Ask Emma


12 April 2018

Should you be taking magnesium with your vitamin D?

Vitamin D is one of the most common nutritional deficiencies in the UK, with around 1 in 4 estimated to suffer from low levels of this nutrient.This is hardly surprising when you consider that vitamin D is not produced by your body and your main way of synthesising the nutrient is sunlight, a scarce commodity considering the natural climate of the British Isles, particularly during the winter months.

That’s why many have turned to supplements, which can sometimes cause problems. Your body is only designed to utilise so much vitamin D and, since most supplements contain up to 2 or 3 times your recommended daily dose, your body will store any excess and you may risk vitamin D toxicity – less is sometimes more, as I cover in my blog, ‘Are you taking too much vitamin D?

However, recently another piece of evidence has arisen that indicates that, even if you are taking a supplement, you still may not be getting enough vitamin D which is primarily to do your intake of magnesium

Magnesium is the fourth most abundant mineral in your body but, like vitamin D, deficiencies are not uncommon. Since magnesium is essential for healthy muscles and joints as well as your metabolism, low levels of this mineral can result in aches, pains and quite often, fatigue. However, did you know that your body needs magnesium to activate vitamin D?

This is because magnesium plays a crucial role when it comes to activating your enzymes, including the ones that play a role in how vitamin D is metabolised. Since vitamin D is often stored within your body in its inactive form, it needs magnesium to become activated so, even if you’re taking a supplement, you might not be getting all the benefits. One study conducted in 2013 even found that those that consumed high levels of magnesium were less likely to have vitamin D deficiency.

What other nutrients do you need to consider with vitamin D?

Okay, so vitamin D relies on magnesium but it isn’t the only mineral that you need if you want to get the most out of vitamin D. Calcium, vitamin K, magnesium and vitamin D all exist in a delicate balance and your body relies on specific amounts of each to function properly. Too much vitamin D, for example, and not enough vitamin K can sometimes stimulate the over-absorption of calcium, which as I shall explore, may deplete your stores of magnesium.

What other synergetic relationships should you consider?

The relationship between magnesium and vitamin D is far from unique – how efficiently your body absorbs any vitamin or mineral can rely on a specific balance of other minerals. However, while I could be here all day discussing each association, I’m going to focus on the vitamins and minerals that, like vitamin D, the general populace is often lacking and sometimes over-supplementing. 

Magnesium, B vitamins and calcium

As I’ve mentioned, you need magnesium to properly utilise vitamin D, but not unlike vitamins, magnesium deficiencies are common. However, unlike vitamin D, magnesium can be found in a variety of different food products and it’s relatively easy to increase your dietary intake without having to rely on supplements. 

However, sometimes the absorption of magnesium can be hindered by certain digestive disorders like Crohns or IBD. You also have to consider that your body’s demand for magnesium can sometimes increase, which is why our Menopause Expert Eileen sometimes recommends increasing your intake during menopause

In these instances, maximising your body’s ability to absorb magnesium can be beneficial. This is when it becomes important to talk about two other nutrients in particular – B vitamins and calcium. Your body relies on 8 different B vitamins, which mainly work to support the nervous system and your metabolism, but it can also affect your absorption of magnesium too. Vitamin B6 in particular, alongside the often overlooked mineral selenium, helps your body to absorb calcium. 

So, where does calcium come into the picture? Well calcium and magnesium are often seen as opposites – calcium helps your muscles to contract whereas magnesium causes them to relax. You need a balance of both to function properly. Too much or too little calcium can have a big influence on how well magnesium is absorbed, with too much calcium depleting your stores of magnesium. This doesn’t mean that you should boycott calcium for the sake of magnesium though – remember, balance is the key word here!

Iron and vitamin C

Similar to magnesium, iron-deficiency and anaemia is a real problem here in the UK, especially with menstruating women, vegans and vegetarians. This is because iron is not always well absorbed by your body. There are two main forms of iron you can intake from your diet – heme iron and non-heme iron.

Heme iron is more easily absorbed by your body – it’s estimated that around 15-35% of the heme iron you consume is absorbed by your body.3 Unfortunately, meat and poultry are the main sources of heme iron so most people turn to non-heme iron, which is commonly found in plant-based foods but isn’t as well absorbed. In fact, sometimes as little as 5% of what you consume is actually absorbed by your body. 

This is why, if you are vulnerable to an iron deficiency, it’s important to consider other nutrients that may help to optimise how you absorb and utilise iron. As I discussed in my blog, ‘What happens when you are low in iron?vitamin C  can play a role in increasing iron absorption but, more specifically, non-heme iron absorption which is good news for vegans and vegetarians.4  

However, as with magnesium, certain nutrients like calcium can inhibit your absorption of iron. With iron though, the bigger concern is phytic acid, the stored form of phosphorus. Although it is sometimes called an ‘anti-nutrient’ it’s believed that phytic acid may have some benefits for your cardiovascular system and can act similar to an antioxidant so again, don’t completely eliminate this nutrient from your diet!

What’s the best way to achieve a balance?

Working out how to achieve a good balance of nutrients can be confusing. However, you should remember that, in order to increase your intake of one nutrient, you shouldn't restrict your intake of another. Just because you want to increase your levels of iron doesn’t mean you should immediately boycott calcium. 

The real problem that you need to be aware of is over-supplementing, or getting far too much of one nutrient compared to your recommended daily allowance and the ration of other nutrients you need. That’s why it’s always preferable to try increasing your intake through your diet first, before resorting to supplements and even then, be label savvy. 

Know how much of each nutrient you should be getting on a daily basis and how much it is safe to supplement. For example, if you are going to take a vitamin D supplement during winter it’s recommended that you don’t exceed 10mcgbut most supplements found on the high street or even in health food stores drastically exceed this limit. 

Try to opt for a supplement that offers a mild dose and includes a few of the nutrients that may potentially increase your absorption. For example, Floradix’s Liquid Iron Formula, which I often recommend for those that suffer from heavy periods, doesn’t just contain iron, it contains a blend of iron, B vitamins and vitamin C to help optimise absorption. 

If you’re looking to gently increase your intake of trace minerals like zinc and potassium, which often get overlooked, as well as calcium and vitamin D, you could try our Balance Mineral Drink. This strawberry flavoured beverage works well as a post-workout drink, replenishing your levels of key electrolytes and helping to keep you hydrated. 

It’s also often recommended for fatigue and each 5.5g sachet contains 100% of your NRV (Nutrient Reference Values) of vitamin D3 as well as 30% of your calcium and magnesium NRV too! 

If you want to learn more about how much of each vitamin and mineral you should be getting each day, as well as potential food sources and even delicious recipes, please check out our vitamins and minerals pages here

Video: Fermented Tomato Ketchup

Ready to try something new? Watch Emma's recipe video for a delicious Fermented Tomato Ketchup!

Get the recipe

What are superfoods?

You've probably heard all the fuss about superfoods, but what does this mean, and what foods count as superfoods?

Find out now

How many fruit and veg portions?

Is 10 portions of fruit and vegetables daily really achievable? Our nutritionist Emma Ross tells us her thoughts.

Learn more

Kick it up a notch!

Our Herbamare combines herbs and vegetables with a little sea salt to create a delicious, healthy seasoning for any dish!

Find out more

Healthy & nutritious dinner ideas

Get new recipes in your inbox every week. Sign up now

Super Smoothies e-Book