Are vitamin B12 and magnesium the perfect supplement pairing for better energy?
Reviewed by Dietitian Katey Davidson, M.Sc.FN, RD, CPT
Key Points
- Vitamin B12 and magnesium help your body produce and use energy.
- Taking them together is safe, but isn’t needed for better absorption or efficacy.
- A food-first approach is best, though supplements can help fill potential gaps.
Feeling sluggish is a frustrating but common problem, and many people may turn to vitamin and mineral supplements to help get their spark back. The nutrients you consume play a major role in how your body creates and sustains energy throughout the day. Among the most popular options in the supplement aisle are vitamin B12 and magnesium.
Both nutrients have strong reputations for supporting overall health. But are they more effective when you take them together? We spoke with nutrition experts to uncover exactly what happens to your energy levels when you combine these two powerhouse nutrients, and whether this combination is the right choice for you.
Should You Take Vitamin B12 and Magnesium Together?
For most people, taking vitamin B12 and magnesium together is safe and may even be beneficial, since they don’t compete for absorption. Instead, they work as a team to keep your body functioning at its best.
“Taking B12 and magnesium together can be helpful because they support different but complementary aspects of energy and muscle function,” says Johnnah Katz, MA, RDN.
Vitamin B12 supports red blood cell production and nerve health and helps cells convert food into usable energy, while magnesium aids muscle function, nerve signaling and energy metabolism. Together, they help your body use energy efficiently while keeping muscles and nerves working properly.
However, some people should be careful. Those with impaired kidney function should consult a health care provider before taking magnesium supplements, as their kidneys may struggle to clear excess amounts from the blood. Additionally, certain medications, like acid reflux drugs or specific antibiotics, can interfere with the absorption of vitamin B12 or magnesium, so it’s best to seek medical guidance before starting a new supplement routine.
Does Pairing Vitamin B12 and Magnesium Improve Energy?
If you’re hoping for an immediate jolt of energy like you’d get from a cup of coffee, you may need to reset your expectations. This combination doesn’t act like a stimulant per se, but it can support how your body generates and uses energy at a cellular level.
“Vitamin B12 supports energy by helping the body convert our food into usable cellular energy (ATP),” explains Sophia Deahl, M.S., RD, IFMCP. “Vitamin B12 plays an important role in making healthy red blood cells, which carry oxygen to tissues supporting physical and mental energy.”
When you add magnesium to the mix, you support the systems that use that energy. As Katz points out, “Magnesium is essential for muscle relaxation, nerve signaling and hundreds of enzymatic reactions.”
If you’re deficient in either nutrient, your body may struggle to perform basic tasks, which may leave you feeling sluggish. Together, they address fatigue from two different angles: B12 helps generate energy, while magnesium helps your muscles and nerves use it efficiently.
That said, taking them together doesn’t enhance their absorption or amplify their effects. They work independently, so you don’t have to take them at the same time to benefit, but you can if it suits your routine.
How Much Should You Take?
Understanding the proper dosage is crucial for getting the most out of your supplements without experiencing negative side effects.
For vitamin B12, the recommended daily intake for adults is 2.4 micrograms. Pregnant women need 2.6 mcg and breastfeeding women need 2.8 mcg. Since vitamin B12 is water-soluble, your body simply excretes what it does not use through urine. Therefore, there is no established Tolerable Upper Intake Level (UL) for B12, and toxicity is exceptionally rare.
For magnesium, the recommended daily intake is 310 to 320 milligrams for adult women and 400 to 420 mg for adult men. Pregnant women need about 350 to 360 mg daily. Magnesium from supplements does have a UL of 350 mg per day unless otherwise directed by your health care provider. Exceeding this amount may cause gastrointestinal side effects such as diarrhea, nausea and stomach cramping.
How much of each supplement you should take depends on many factors, including diet, health status and medications, so it’s best to work with a health care provider to determine what’s right for you.
How to Take Vitamin B12 and Magnesium Together
You can take vitamin B12 and magnesium together or separately, depending on your preference.
Some people opt for a multivitamin blend that contains both vitamin B12 and magnesium, which is convenient if you want to limit the number of pills you swallow. Others prefer separate supplements, which allows for more flexibility with timing.
Although both vitamin B12 and magnesium play roles in energy metabolism, they can have different effects on how you feel. Vitamin B12 is often taken in the morning, as some people report feeling more alert after taking it—though, this is mostly anecdotal. Magnesium, on the other hand, is famous for its role in muscle relaxation and is commonly taken in the evening to support better sleep.
Food Sources
Supplements can be helpful, but a food-first approach is always the best place to start. Here are some whole-food sources to add to your grocery list.
Vitamin B12 Food Sources:
- Beef and liver
- Fish (e.g., salmon, trout and tuna)
- Shellfish (e.g., clams and oysters)
- Eggs
- Dairy products (e.g., milk, cheese and yogurt)
- Fortified nutritional yeast
Magnesium Food Sources:
- Leafy green vegetables (especially spinach and Swiss chard)
- Seeds (e.g., pumpkin seeds and chia seeds)
- Nuts (e.g., almonds and cashews)
- Legumes (e.g., black beans and edamame)
- Dark chocolate
Our Expert Take
Vitamin B12 and magnesium are both important nutrients for supporting the body’s natural energy systems. While they won’t give you the quick jolt of an energy drink, they work behind the scenes to keep your cells, muscles and nerves functioning properly. Although getting these nutrients through food is ideal, supplements can offer a helping hand.
Taking vitamin B12 and magnesium together is safe and may support energy levels, but they’re just as effective when taken separately. Whether you increase your intake through food, individual supplements or a combined formula, getting enough of these two nutrients is a smart, science-backed way to help reduce fatigue.
Frequently asked Questions
Can I take magnesium and B12 together?
Yes, you can take magnesium and vitamin B12 together. They support different functions in the body and do not compete with one another for absorption.
Does magnesium stop B12 absorption?
No, magnesium does not interfere with the absorption of vitamin B12.
What time of day should I take magnesium and B12?
You can take them together at any time or separately, depending on your preference. If you choose to space them out, try taking vitamin B12 in the morning to support your daytime energy levels and magnesium in the evening for sleep.
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