Magnesium and vitamin D—benefits, dosages and which types of supplements to take

In this guide, we explain:

  • the effects of taking vitamins and minerals together
  • the benefits of both magnesium and vitamin D
  • the causes and signs of vitamin D deficiency
  • what types of vitamin D supplements are most effective

Click on a link below to jump to the relevant section:

Taking vitamin D and magnesium together

Magnesium plays a key role in determining how much vitamin D our bodies can make. It’s suggested that people whose magnesium intake is high are less likely to have a vitamin D insufficiency than people whose magnesium levels are low.

It’s also claimed that magnesium supplementation increases vitamin D levels in people who are deficient in the vitamin, but causes a reduction in people whose intake is high. Too much vitamin D can increase calcium levels, which in turn can lead to certain health complications.

Do you need magnesium to absorb vitamin D?

Like any vitamin or mineral, vitamin D can’t work without first being converted into a form your body can absorb. The level to which a vitamin or mineral can be absorbed is known as its “bioavailability”.

Vitamin D’s bioavailability depends on magnesium. The enzymes (in the liver and kidneys) that enable vitamin D metabolism—converting it into its active form, calcitriol—can’t work without sufficient amounts of magnesium to draw upon.

Unconverted, vitamin D can actually increase your calcium levels rather than regulate them as they should. And exceeding your recommended dietary allowance of calcium can stimulate your hormones into drawing the mineral out of your bones—where it’s needed—and depositing it in soft tissues such as arteries.

Can I take magnesium with other minerals and vitamins?

Yes. Vitamins and minerals all work in combination and rely on each other to be fully effective.

Taking magnesium helps your body to absorb and use minerals such as calcium, phosphorus and potassium, and vitamins like vitamin D.

If you take vitamin D supplements, they won’t work properly in strengthening your bones unless the concentrations of boron, magnesium and zinc, and vitamins K and A, are at the correct levels.

Health benefits of magnesium and vitamin D

Why magnesium is good for your body

Magnesium is one of several essential minerals your body needs to stay healthy and function as it should. It benefits you in a whole variety of ways, by:

  • relieving muscle tension and muscle spasms
  • reducing tiredness and fatigue
  • enabling you to wind down before bed, improving the quality of your sleep
  • helping muscle tissue to recover after exercise and sports
  • making you more flexible
  • repairing and replenishing skin, leaving it supple and giving it a natural glow

Magnesium also improves your joint health by increasing the density of your bones, making them stronger. Not only that, but it contributes to your metabolism, the functioning of your nervous system and your body’s synthesis of proteins.

If you have a magnesium deficiency (when your body’s magnesium levels are too low), this might cause you to:

  • sleep poorly
  • feel fatigued
  • experience heart palpitations

Why vitamin D is good for your body

Vitamin D has a number of important functions—for example, it:

  • improves your body’s calcium absorption (calcium levels have an influence on how you absorb magnesium)
  • enables your immune system to function properly, protecting you from illnesses such as the common cold
  • regulates blood pressure
  • aids in the growth and development of bones and teeth
  • helps keep muscles healthy

It’s often referred to as the “sunshine vitamin” as your body produces it naturally when directly exposed to sunlight. Your vitamin D levels also depend on the foods you eat and any supplements you take (see Your magnesium and vitamin D intake below).

Your magnesium and vitamin D intake

If your daily diet is varied and balanced—made up of magnesium-rich foods such as spinach, nuts, beans and wholegrains—it’s likely you’re getting a lot of the magnesium you need. However, food sources don’t always provide the full daily recommended amount so you might need to support your dietary magnesium intake with supplements.

With vitamin D, it’s different. You get much of your vitamin D from direct exposure to sunlight, which isn’t really a concern during the spring and summer months. In autumn and winter, however, it’s difficult to get enough of the vitamin through sun exposure, so taking supplements is crucial.

Although you might get some vitamin D via your diet—in foods such as oily fish (e.g. fresh tuna and mackerel), egg yolk, milk and fortified foods such as margarines and breakfast cereals—this dietary allowance alone isn’t enough to keep your intake at healthy levels.

How much magnesium should you take? Should you take it every day?

Adults (aged 19–64) should take no more than 300 mg (men) or 270 mg (women) of magnesium per day. The advised doses for children are much lower and depend on age—click here to read more.

However, these guidelines only apply to oral supplements such as tablets and capsules. There’s no limit for transdermal magnesium supplements (those you apply directly to your skin).

How much vitamin D should you take?

Public Health England recommends that adults take at least 10 micrograms (mcg) of vitamin D each day, particularly during autumn and winter. Children under the age of five should take the same amount all year round.

Babies under one year old should have a daily supplement of 8.5–10 mcg, unless they’re consuming more than 500 ml of infant formula (which is fortified with vitamin D) each day. Supplements should be administered from soon after birth as there isn’t enough natural vitamin D in a normal diet, nor are babies exposed to enough sunshine to produce the vitamin naturally.

Without sufficient vitamin D, babies can develop problems with their bones and muscles.

The Department of Health highlights certain “at-risk groups” and recommends that they take a vitamin D supplement all year round. These groups include:

  • women who are pregnant or breastfeeding
  • elderly people (aged 65 years and over)
  • people who have little or no exposure to the sun
  • people who have darker skin

What causes a vitamin D deficiency?

As we get 80%–90% of our vitamin D from sunlight, anyone who spends little time outdoors is at risk of becoming deficient.

And when we do venture out into sunny weather, many of us use SPF (sun protection factor) creams and cosmetics to protect our skin. However, the ingredients in these products block the UV rays that the skin needs to be able to produce vitamin D.

Around 1 billion people across the world—including around 10 million people in the UK—are said to be deficient in vitamin D.

What are the symptoms of vitamin D deficiency?

If you’re not getting enough vitamin D, this might lead to:

  • aching and/or weakened bones
  • weak muscles
  • feelings of depression
  • an increased vulnerability to coughs and colds
  • gut problems

For many people, the symptoms are fairly subtle and won’t cause any serious risk to your health. However, it is possible for a vitamin D deficiency to bring about more harmful complications if left untreated.

There are simple blood tests you can do at home to check whether your vitamin D levels are low. These give you an accurate reading of the amount of vitamin D in your blood. You then send off the tester and receive the findings back via email. Read more about BetterYou’s vitamin D testing service here

What type of vitamin D is best?

Vitamin D comes in two major forms, vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol).

The human body can absorb and process both forms. However, as vitamin D3 occurs naturally as your body’s response to sunlight, it’s generally considered the preferred form of supplementation.

Vitamin D3 supplements are typically made using lanolin, a type of wax extracted from sheep’s wool. However, at BetterYou, we use a plant-origin source of D3 in our Vegan Health Oral Spray and Vegan DLux 1000 Oral Spray.

Which vitamin D supplements are best: tablets, capsules or sprays?

Tablets, capsules and oral sprays have all been proven to be effective methods of raising nutrient levels. So, it does come down to personal preference.

While lots of people take vitamin D tablets or capsules, at BetterYou we’ve pioneered a method of vitamin D supplementation in the form of oral sprays. These have the advantage of delivering vitamin D directly into the mouth, where the soft tissues and rich vein systems can absorb it, rather than relying on the digestive system.

Watch our YouTube video on how vitamin oral sprays work.

Related content

Magnesium supplements—are they safe and what dosage should you take?

5 signs you’re not getting enough vitamin D

Public Health England advises vitamin D supplements for all

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