Magnesium Plus

Magnesium and Vitamin D: Should You Take Them Together?

Magnesium and vitamin D are some of the most common nutritional deficiencies. A supplement is a great way to top up your levels of these essential nutrients, but should you take vitamin D and magnesium together? We say yes! In this article, we’ll break down exactly why, and we’ll tell you how to get the best out of this synergistic supplement combo….

What is magnesium and vitamin D? 

Magnesium is an essential mineral that plays a part in:

  • Muscle movement  
  • Nerve function
  • Heart rhythm
  • Heartbeat 
  • Bone synthesis
  • Blood sugar control
  • Blood pressure regulation
  • Immune system regulation
  • Energy production
  • DNA, RNA, and protein synthesis

Vitamin D is actually a hormone that you make when your skin is exposed to direct sunlight. Some plants and animals produce vitamin D, too, which is why you’ll naturally find small amounts of this vitamin in certain foods. However, the vast majority of your vitamin D will come from you, rather than your diet. 

Vitamin D plays a major role in: 

  • Bone health
  • Immune function 
  • Muscle strength 
  • Heart health 
  • Blood vessel function 
  • Mood regulation

How much magnesium and vitamin D do you need?

The recommended magnesium dosage and intake vary depending on your age and sex. The tables below show the adequate intake (AI) and recommended dietary allowance (RDA) from the National Institute of Health.

Recommend magnesium dosage:

Birth to 6 months30 mg*30 mg*
7–12 months75 mg*75 mg*
1–3 years80 mg80 mg
4–8 years130 mg130 mg
9–13 years240 mg240 mg
14–18 years410 mg360 mg400 mg360 mg
19–30 years400 mg310 mg350 mg310 mg
31–50 years420 mg320 mg360 mg320 mg
51+ years420 mg320 mg

Recommended vitamin D dosage:

0-12 months*10 mcg
(400 IU)
10 mcg
(400 IU)
1–13 years15 mcg
(600 IU)
15 mcg
(600 IU)
14–18 years15 mcg
(600 IU)
15 mcg
(600 IU)
15 mcg
(600 IU)
15 mcg
(600 IU)
19–50 years15 mcg
(600 IU)
15 mcg
(600 IU)
15 mcg
(600 IU)
15 mcg
(600 IU)
51–70 years15 mcg
(600 IU)
15 mcg
(600 IU)
>70 years20 mcg
(800 IU)
20 mcg
(800 IU)

*Adequate Intake (AI)

What happens if you don’t get enough? 

Both vitamin D and magnesium are absolutely critical for good health and proper function of your body. Here’s what may happen if you don’t get enough of either…

Magnesium deficiency 

Your body can’t produce magnesium by itself, so you have to get it from your diet (or from supplements). Unfortunately, lots of people are believed to be deficient, and many don’t even realize. Possible reasons for magnesium deficiency include: 

  • Not eating enough magnesium-rich foods. 
  • Eating foods with depleted magnesium content due to poor soil quality and/or processing).
  • Health conditions that affect magnesium absorption, e.g. gastrointestinal disorders like Crohn’s disease. 
  • Health conditions that increase magnesium excretion, e.g. kidney disease. 
  • Medications that affect magnesium absorption or excretion.

Given how many functions and processes in your body rely on magnesium, a deficiency can have serious consequences. Even a relatively mild magnesium deficiency is linked to cardiovascular disease and other serious health issues like stroke, type 2 diabetes, Alzheimer’s, and osteoporosis. 

It can be difficult to tell if you have a magnesium deficiency, but you can look out for telltale signs and symptoms like: 

  • Fatigue
  • Weakness 
  • Muscle cramps, stiffness, or spasms
  • Eye twitches
  • Headaches or migraines
  • Nausea 
  • Numbness or tingling
  • Irregular heartbeat or palpitations (a “fluttering” sensation in your chest)
  • Anxiety, depression, or low mood

Vitamin D deficiency 

In the UK, the NHS says that most people should be able to make all the vitamin D they need from sunlight from March to September. However, many people are unable to make enough during the autumn and winter months because of weaker sunlight and fewer daylight hours. This is the most common cause, but there are several additional risk factors for vitamin D deficiency: 

  • Little outdoor time. People who generally spend very little time outdoors are more likely to have a vitamin D deficiency, even in the spring and summer months. These might include people who work in offices or homes all day, people who live in residential care settings, or people who are housebound due to poor health. 
  • Physical barriers. Even if you do spend plenty of time outdoors, wearing clothes that cover most of your skin can prevent you from making vitamin D. If you live in a big city, tall buildings can block sunlight, while air pollution can block the sun’s UVB rays. 
  • Skin colour. People with darker skin are at greater risk of vitamin D deficiency. That’s because melanin, the pigment responsible for skin tone, blocks vitamin D synthesis. The darker your skin, the more melanin it has, and the less vitamin D you’ll make. 
  • Diet. Even though most vitamin D is made in the body, not getting enough in your diet may contribute to a deficiency. Vitamin D is naturally found in dairy, eggs and fish, so people who are lactose intolerant, vegetarian or vegan are at greater risk. 
  • Obesity. Vitamin D is a fat-soluble vitamin, which means it can be stored in your adipose (fat) tissue. In people who are overweight or obese, the excess adipose tissue takes up more vitamin D, leaving less available in the blood. They may then find themselves with a functional deficiency even if they’re getting the recommended amounts of vitamin D. 
  • Malabsorption. Because vitamin D is fat-soluble, it also depends on dietary fat for absorption in the gut. If you have a diet very low in fat, or a health condition that affects fat absorption, e.g. ulcerative colitis, then you may also struggle to absorb vitamin D. Gastric band surgery sometimes removes the part of the small intestine where vitamin D is absorbed, which can also lead to deficiency. 
  • Medications. Some common medications can also impact vitamin D absorption. These include laxatives, steroids, anti-seizure medications, cholesterol-lowering medications, and weight loss drugs, e.g. Orlistat. 

The main dangers of a vitamin D deficiency are related to the bones. They get their strength from calcium and phosphorus, and vitamin D helps you absorb these two minerals from your food. Without it, then, your bones can end up weak, brittle, and vulnerable to fractures. 

Because of this important role, vitamin D deficiency might show up as bone pain. This is often an ache or uncomfortable sensation that feels like it comes from much deeper than the muscle. It will stick around whether you’re moving or not, and you won’t be able to relieve it with touch, massage, or stretching like you might with muscle pain. 

Other warning signs of vitamin D deficiency include: 

  • Fatigue
  • Mood changes, e.g. depression 
  • Hair loss
  • Frequent infections or illness
  • Slow wound healing

How can I get more magnesium and vitamin D? 

To increase your magnesium levels, the best place to start is your diet. The top dietary sources of magnesium include:

  • Leafy green vegetables
  • Bananas 
  • Avocados
  • Dark chocolate 
  • Soy products
  • Some fatty fish 
  • Whole grains 
  • Legumes, nuts, and seeds 

If you want to get more magnesium on your plate, check out our mega-list of magnesium sources here in our magnesium-rich foods article. 

The best and most reliable way to get more vitamin D is to spend more time outdoors in direct sunlight. Sitting by the window doesn’t count unfortunately! Glass filters the rays that trigger vitamin D synthesis, so it’s important to get outside in the open air, even if it’s just for a short walk at lunchtime. 

There’s a common myth that using sunscreen will prevent you from making vitamin D, but don’t worry! This has been debunked by experts, so there’s no need to skimp on that essential sun protection. 

You can also get a small amount of vitamin D from the following foods: 

  • Oily fish, e.g. salmon, herring, mackerel, tuna
  • Red meat and organ meat
  • Egg yolks
  • Shrimp 
  • Mushrooms

Some milk, cereals, juices, and yogurts are fortified with vitamin D, too, so you can up your intake by switching to a version with added vitamin D.  

If you’re still finding it tough to get enough magnesium and vitamin D from natural sources, you can also try supplements. In fact, the NHS says that everyone in the UK should take a vitamin D supplement throughout the winter months, and those at high risk of deficiency should do this all year round. 

Can I take magnesium and vitamin D together? 

Yes, you can take magnesium and vitamin D together. Here’s why they make the perfect pair…

What are the benefits of taking magnesium and vitamin D together? 

Did you know that your magnesium levels actually control your vitamin D levels? That means you need sufficient magnesium to get the benefits of vitamin D. 

Let’s say you’re trying to increase your vitamin D levels by getting more sunshine, eating fortified foods, or taking a supplement. Before your body can use that vitamin D, it needs to be converted into its active form. 

The enzymes that are responsible for this conversion all depend on magnesium to work. So if you’re not getting enough magnesium, you won’t experience the benefits of vitamin D. You might even end up deficient, even if you’re getting the recommended daily amount. 

So not only can you take magnesium and vitamin D together, you probably should! Here are some of the evidence-based benefits of taking the two together…

1. Bone health 

We already mentioned how vitamin D helps you to absorb calcium and phosphorus from your food. These minerals are used not just to build and harden your bones, but to keep them strong throughout your life. 

Your bone tissue is constantly being broken down and rebuilt in a process called remodeling. Ideally, you want to replace at least the same amount of bone tissue as you break down. You also want to provide the new bone tissue with enough calcium and phosphorus to keep the bones hard and strong (known as remineralization).

For both things, you need a steady supply of vitamin D, but what happens if you don’t get it?

If you break down more bones than you can replace, your bones will lose their density over time and become brittle. This is known as osteopenia in milder cases and osteoporosis in more severe cases. If you can’t remineralize your bones with calcium and phosphorus, your bones won’t harden properly and will become weak and soft. This is known as osteomalacia in adults or rickets in children. 

All of these conditions leave the bones more vulnerable to fractures, and rickets can cause skeletal deformities and development problems in children. For healthy bones, then, experts agree that vitamin D is an absolute must. But where does magnesium come in?

As well as activating vitamin D, magnesium plays its own major role in bone health and strength. In fact, 60% of the magnesium in your body is stored in your bones and needs to be replaced during the remodeling process, just like calcium and phosphorus. If it’s not, it can also contribute to brittle or weak bones. 

Magnesium supplements have been shown to help strengthen and protect the bones, especially during menopause when the risk of osteoporosis is much higher for women. In one short study, 30 days of magnesium citrate slowed down bone loss in menopausal women with osteoporosis. In a longer study of almost 74,000 postmenopausal women, higher magnesium intake was associated with stronger, more mineral-dense bones.

2. Muscle health 

Calcium, vitamin D, and magnesium all work in synergy to help your muscles function. Magnesium is an essential part of the energy production process in your muscle cells and it also activates vitamin D, which then allows you to absorb calcium from your food. Calcium is responsible for contracting your muscle when you use it. The magnesium then relaxes the muscle. Unless you have sufficient levels of all three — not just one or even two — your muscles simply won’t work as well as you need them to. 

Without magnesium, your muscles struggle to relax and may go into spasm. In fact, magnesium deficiency has been associated with conditions like night-time leg cramps and restless leg syndrome (RLS), and supplements are often used to relieve leg cramps in pregnant women.

Magnesium deficiency is also associated with muscle pain and inflammation, but magnesium supplements have been shown to help by:

Deficiencies in magnesium and vitamin D can also impact your muscle strength and exercise performance. After all, if your muscles aren’t functioning at a basic level, they’re going to really struggle when you turn up the tempo! 

You need up to 20% more magnesium during a workout to power your muscle cells and shift metabolic waste. Providing that in the form of supplements has been shown to:

A large review linked vitamin D to significant gains in muscle strength. In a recent study, vitamin D was also shown to increase size, power, velocity, and jumping height in the leg muscles. Interestingly though, this only applied to the active form of vitamin D, which requires… plenty of magnesium! Yet another reason these two nutrients make the perfect pair.

3. Heart health 

Your heart is a muscle too, so getting plenty of magnesium and vitamin D is also essential for healthy heart function. Low vitamin D and magnesium levels have both been linked to increased risk of cardiac conditions like high blood pressure, heart failure, and stroke. 

The Harvard School of Public Health says that vitamin D keeps the immune and inflammation responses associated with heart disease in check. It also helps to keep the blood vessels flexible and relaxed, supporting healthy blood pressure. They discussed a huge study that showed men with the highest levels of vitamin D were the least likely to have strokes or heart disease events.

There is also a ton of evidence supporting magnesium’s ability to keep the cardiovascular system healthy. It’s best known for reducing blood pressure (see here, here, here, here, here, and here), but it can also:

  • Lower the risk of heart disease and stroke. 
  • Increase “good” HDL cholesterol and reduce “bad” LDL cholesterol and triglycerides. 
  • Repair injured cardiac muscle (magnesium orotate).
  • Improve survival rates in congestive heart failure (magnesium orotate).  
  • Protect cardiac tissue (magnesium taurate).

4. Immune health 

During the COVID-19 pandemic, there was a lot of talk about whether vitamin D could help to protect against the disease, or at least reduce its severity. This is still being researched, but one study pointed out that severe respiratory illnesses are associated with vitamin D deficiency, and that outbreaks usually occur in winter when vitamin D levels happen to be at their lowest. 

They say that vitamin D slows down the reproduction rate of viruses, which might prevent more serious infections from taking hold. It can reduce the number of inflammatory cells that damage the lining of the lungs and lead to pneumonia, and it can also increase anti-inflammatory defenders to help fight off disease. 

We’ll have to wait for more research on COVID-19 specifically, but we do know that vitamin D is an immune essential. Sunlight exposure and cod liver oil were used to treat tuberculosis long before we understood that both boosted vitamin D levels. Now, we know that vitamin D has a critical effect on the immune cells and proteins that fight off disease in the body. And if you’re wondering where magnesium fits in this picture, many of these same cells can’t function unless they’re in a magnesium-rich environment

Vitamin D deficiency may also be involved in autoimmune disorders, where your immune system goes rogue and starts attacking your own healthy tissues. Harvard researchers say that a child in Finland is 400 times more likely to develop autoimmune type 1 diabetes than a child in sunny Venezuela. However, for Finnish children who are given vitamin D from birth, their type 1 diabetes risk is nearly 90% lower than kids who are given no supplements. They also talked about similar links between vitamin D levels and other autoimmune disorders like multiple sclerosis, rheumatoid arthritis, psoriasis, and autoimmune thyroiditis. 

5. Mood 

Vitamin D plays an important role in regulating your mood. So it’s probably not a coincidence that Seasonal Affective Disorder (SAD), or winter depression, kicks in right as the days get shorter, sunlight gets weaker, and we spend less time outdoors. In fact, low levels of vitamin D have been associated with several different types of mood disorders, and supplements have been shown to improve depression symptoms and negative emotions

Magnesium is also a key player in emotional and mental health. It’s needed for the creation of neurotransmitters like serotonin, which helps to regulate mood and sleep and promote feelings of well-being. Unsurprisingly, deficiency is linked to anxiety, depression, and various other mood disorders, but research has found that magnesium supplements can: 

Are there any side effects from taking magnesium and vitamin D supplements? 

So you’ve heard the positives, but are there any downsides to taking magnesium and vitamin D supplements? As long as you follow the instructions on your supplement, the answer is usually no!

Magnesium supplements are safe for most people, but higher doses (above 375-400mg) are associated with digestive side effects like nausea, bloating, or diarrhea. You can reduce the risk by sticking to the recommended dosage and taking a well-tolerated magnesium type like magnesium malate, magnesium taurate, or magnesium glycinate. However, if you do experience side effects, they can usually be resolved quickly by simply lowering your dose.

You should also know that some health conditions can affect how your body absorbs or gets rid of magnesium. Also, magnesium can interact with some medications and affect how they work. If you have pre-existing conditions or you take medications, then, it’s always best to run it by your doctor before taking a magnesium supplement.

Vitamin D is also safe if taken as directed, but be careful of super-strength supplements. Too much inactive vitamin D can cause your blood calcium levels to increase. That excess calcium can be deposited into your soft tissues and organs, rather than the bones, and can cause the blood vessels to harden. Over time, this can lead to serious heart and kidney problems. 

Taking magnesium with your vitamin D can help to lower that risk because it turns vitamin D into its active form. However, it’s still recommended to take no more than 4,000 IU of vitamin D per day in a supplement.