MG – Why you need it and how to get it

Colleen Gray-Hewett Blog

MG: Magnesium

Master mineral.  Essential nutrient.  Crucial to much of your immediate and long-term health. Deficient in most adults today yet simple to add!

Did you know that magnesium is required in over 300 enzymatic reactions in our bodies? This includes, but not limited to, muscle function (contraction and recovery), nerve function, protein synthesis, blood pressure, cardiovascular health, bone building, brain chemistry, sleep, and prevention or reduction of pre-menstrual symptoms.

  • Muscles: Magnesium plays a key role in keeping your muscles contracting longer, with less cramping, keeps energy levels higher longer and aids muscle recovery.  Adequate MG is key for athletic performance in all sports and endurance athletes in particular.  Look for magnesium in your electrolyte drink when racing, particularly when temperatures are hot.  Topical magnesium sprays are also beneficial for certain sport-induced aches and pains.
  • Type 2 Diabetes:  Low magnesium levels are directly linked to low insulin sensitivity (we want high sensitivity) and impaired insulin secretion, which are main problems for type 2 diabetics.  The more deficient you are, the more susceptible you will be to developing the disease.  The more you increase your MG through food and supplementation (up to a certain level), the lower your risk of developing type 2 diabetes.  Magnesium is also helpful and used in the treatment of existing diabetes and pre-diabetes cases.
  • Bone Health: Magnesium is essential to work alongside calcium and aids in the activation of Vitamin D in the kidneys.  It leads to higher bone density formation and ongoing maintenance of your bone density, thereby important in the prevention of osteoporosis.  Your teeth will be stronger too!
  • Sleep: Magnesium is best taken at night as it is believed to reduce cortisol levels and signal muscle relaxation which are both key for sleep and perhaps not so great during the day.  An epsom salt bath is great before bed for muscle recovery and sleep inducement as our skin – our largest organ –  absorbs the magnesium.  
  • Constipation: While dietary fibre is key for prevention of constipation, magnesium can help relieve any periodic back-ups.  This is another good reason to take your magnesium supplement at night and will help you determine the proper dosing.  Too high a dose for you may be indicated by too loose in the morning.  Magnesium citrate is more diuretic than magnesium bys-glysinate so assess your needs when choosing which form.

There are many other amazing things that magnesium does for you and if you have questions, please ask (  In the meantime, lets look at how to get MG into your diet naturally and then with supplements, if need be.  First, know that the best sources of magnesium are plant foods.  Unfortunately, even the best food sources may not have the stated levels of magnesium due to soil degradation through mono cropping and high use of pesticides so while we should make best efforts with our food, a high quality, vegan magnesium supplement either daily or periodically is recommended.  Here are the best food sources (note that Cornflakes are a processed food and that the dairy products listed are very low in magnesium which does not assist with calcium absorption)  I believe the quantity is 1/2 cup of all foods in the table:

Table 1: The Magnesium Content Of Common Foods
Pumpkin seeds (roasted)
Brazil nuts
Sesame seeds
Peanuts (roasted, salted)
Rice (whole grain brown)
Wholemeal bread
Cooked beans
Potato (baked)
White bread
Yoghurt (plain, low fat)
Rice (white)
Source; USDA Nutrient Database

Nuts and seeds are the magnesium powerhouses but are also high in fat (good, unsaturated fat but still fat) so eating a 1/2 cup per day on a regular basis may not be advised for my clients, depending on the individual circumstances.  A combination of several of the foods are easy throughout the day to achieve your recommended daily amount (RDA):

Table 1. Recommended Dietary Allowance (RDA) for Magnesium
Life Stage Age Males (mg/day) Females (mg/day)
Infants 0-6 months 30 (AI) 30 (AI)
Infants 7-12 months 75 (AI) 75 (AI)
Children 1-3 years 80 80
Children 4-8 years 130 130
Children 9-13 years 240 240
Adolescents 14-18 years 410 360
Adults 19-30 years 400 310
Adults 31 years and older 420 320
Pregnancy 18 years and younger 400
Pregnancy 19-30 years 350
Pregnancy 31 years and older 360
Breast-feeding 18 years and younger 360
Breast-feeding 19-30 years 310
Breast-feeding 31 years and older 320

For most of us, aiming to for 310-420mg per day is a good goal.  If you know, based on the food and RDA tables that you are likely coming in low, start supplementing slowly to bowel tolerance.  There are a couple of oral options.  One is Calm, a nightly magnesium powder mixed into a glass of warm water before bed.   The other is a capsule supplement.  Whatever your preference is or have both on hand to vary.  For teens and kids, however you can get them to take it.  There is a Calm for kids which tastes good.  I take a vegan capsule of Magnesium Bys-Glysinate 200mg which is gentler on the bowels compared to Magnesium Citrate as mentioned above.  Ask your local health and wellness provider which might be best for you if you are planning to add supplementation to your diet.

I likely exceeded my RDA with food alone today.  I had beans, cooked spinach, avocado, pumpkin seeds and a few other plant-sources of magnesium.  Nutrient density means your food provides you with much of the vitamins and minerals you need through complete, whole plant foods while filling you up with more food.  Its knowing what and how to put foods together to create your optimal daily health.  Sleep well!

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