Types of Magnesium Supplements - A Pharmacists Guide to Magnesium Glycinate vs Magnesium Citrate

November 09, 2021 3 min read

magnesium glycinate vs magnesium citrate

Magnesium is the fourth most common mineral found in our body and is involved in more than 300 enzymatic reactions. 

It is essential for protein synthesis, muscle contraction, blood glucose control,  regulate blood pressure, normal nerve function, cell division and energy production.

Magnesium can also be absorbed through the skin to produce muscle relaxation effects, reduce swelling and also has soothing properties. 

It is no doubt Magnesium is essential and luckily, Magnesium can be obtained readily through our diet. Dietary sources of Magnesium include nuts, whole grains, such as brown rice and grain products, fish, seafood, several vegetables, legumes, and berries.

It is important to note calcium and magnesium intake can influence each other’s absorption. Too much calcium relative to magnesium can result in constipation, interfere with muscle contraction and even cause kidney stones.

So... if magnesium is found in so many different types of food, why is there a rise in magnesium deficiency in Western society?

There is increasing evidence dietary magnesium is on the rise and it is most likely due to:

  • Higher processing of foods,
  • Lower soil levels of Magnesium used to grow our vegetables,
  • Reduced absorption of Magnesium due to Vitamin D deficiency,
  • Medicines such as Diuretics, Antacids, certain Antibiotics can reduce Magnesium levels, and 
  • Alcohol and caffeine - can increase magnesium excretion.

 

The recommended daily intake of magnesium in adult females is 310mg and 410mg for males. Increasing age, pregnancy, and lactation all affect how much magnesium we need.

magnesium rich foods

Signs of Magnesium Deficiency 

It is important to note the following signs and symptoms should be used as a guide only and serum magnesium levels (a blood test) is the most accurate method to determine magnesium deficiency. 

  • Nausea, vomiting 
  • Muscle cramps and/or spasms
  • Fatigue, weakness 
  • Unable to think clearly
  • Migraines

 

 Which type of Magnesium is best?

 Magnesium Citrate vs Magnesium Glycinate vs Magnesium Oxide vs ... Yes, we get it! The list appears endless, compounded by the fact brands may use more than one type of magnesium in their formulation. 

We break down each form of magnesium below, and who it is more likely suitable for. 

 

Magnesium Citrate is found to have much greater bioavailability when taken on an empty stomach compared to Magnesium Oxide.  It also has a mild laxative effect by attracting water into the colon.

Magnesium Ascorbate is Magnesium bound to Ascorbic Acid. It is a buffered form of Vitamin C and Magnesium offering better GI tolerance and also has good bioavailability.

Magnesium Diglycinate is a chelated form of magnesium and the amino acid glycine. The presence of glycine improves the solubility of the whole compound, therefore increasing its bioavailability. Due to the presence of glycine, this form has been shown to have a calming effect on the nervous system, making it ideal to aid sleep.  

The difference between Magnesium Glycinate and Magnesium Diglycinate is the later has two glycine amino acids attached. Some studies suggest the diglycinate form exhibit greater bioavailability. 

Magnesium Oxide has a very low absorption rate due to it low solubility. Supplements made with Magnesium Oxide or Magnesium Hydroxide tend to be larger in size to make up for their low bioavailability.

Magnesium Chloride is a magnesium salt bound to chlorine. It is completely ionized across a large pH range, from a pH 2 (found in stomach acid) to pH 7.4 (found in blood and lymph) and is well absorbed. 

The chloride part of the compound produces Hydrochloric Acid in the stomach to enhance its own absorption. This is useful for anyone with low stomach acid (production of stomach HCl is known to decline with age) or taking antacids.

Magnesium Chloride is also well absorbed via the skin, making it an ideal form for topical applications such as magnesium sprays and magnesium oils. 

Magnesium Sulfate can be found in supplements or also commonly known as Epsom Salts. Epsom Salt baths are commonly used to relieve sore muscles. Oral bioavailability is limited and is better for intravenous preparations. 

 

There are lots of different ways to use magnesium supplements and choosing a product can be confusing. Nonetheless, we hope this summary is useful when it comes to choosing your next magnesium supplement.

As always, check with your healthcare professional before starting on any supplement to ensure it is appropriate for you. 

 

Author:

Helen Huynh (B.Pharm) MPS

Pharmacist and Cosmetic formulator. 

 

 

References: 

  1. Magnesium: Fact Sheet for Health Professionals. National Institute of Health. Published August 202. Access: https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/
  2. What you should know about magnesium. Harvard Health Publishing. Published December 2017. Access: https://www.health.harvard.edu/staying-healthy/what-you-should-know-about-magnesium2