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Magnesium Supplements Review (Including Calcium, Vitamins D & K, and Boron)
Summary: What You Need to Know About Magnesium Supplements
What is magnesium? Magnesium is an essential mineral for proper metabolism and nervous system functioning, including helping to maintain the electrical stability of the heart. Although magnesium can be easily obtained through the diet and overt magnesium deficiency is not common, many people do not get adequate amounts of magnesium and can benefit from increasing magnesium intake from foods or supplementation. Conditions that may deplete magnesium include alcohol abuse, diabetes, diseases of the digestive tract, and use of medications such as Nexium and Prilosec.
What does magnesium do? Inadequate intake of magnesium may modestly elevate blood pressure and increase the risk of osteoporosis and fractures. In addition, supplementing with magnesium may be helpful for conditions such as migraines and menstrual pain and it is an effective laxative and antacid. It may also improve glucose status in people with prediabetes -- particularly if they are low in magnesium. It also helps control levels of vitamin D and can boost low levels. Maintaining adequate magnesium intake also has cardiovascular benefits, and maintaining a proper ratio of magnesium to calcium intake may have cognitive benefits (See What It Does).
How much magnesium do I need? If you are not getting at least 300 to 400 mg of magnesium from your diet, consider a supplement that will get you to that level.
What did CL find? Among the products ConsumerLab.com selected for testing, two magnesium-only supplements failed review because they contained less magnesium than listed or were contaminated with lead and two magnesium formulas failed for incorrect amounts of vitamin D, vitamin K, and/or boron (see What CL Found).
Which magnesium is best? Among the products that passed testing and were "Approved" for their quality, CL selected a Top Pick for magnesium that is low in price (just 6 cents per pill), well-absorbed, and in a stable chemical form. CL also selected Top Picks for combination formulas that include magnesium, such as those marketed for bone health that contain calcium, vitamin D, vitamin K, and/or boron.
How do forms differ? Magnesium comes in several forms: Magnesium oxide tends to be less expensive than other forms, but may also be less well absorbed and more likely to cause diarrhea. Forms such as citrate and chloride may be better absorbed. Magnesium chloride is also less likely to cause diarrhea and is recommended if you are taking a higher dose, but is best in liquid form rather than as a tablet. Labels are required to show the amount of elemental magnesium in each serving, but you need to read labels carefully. See What to Consider When Buying for more about the different forms.
What's the right dose of magnesium? When used as a treatment, magnesium is often recommended at doses of 250 to 600 mg daily (which is similar to the daily intake requirement in adults of about 400 mg). However, unless treating a deficiency, limit your daily intake of magnesium from supplements and fortified foods to no more than 350 mg (the Upper Tolerable Intake Level), to avoid side-effects. You can easily get the rest of your required magnesium from your diet. (See What To Consider When Using).
What are the side effects of magnesium? Magnesium supplements may cause upset stomach, nausea, or diarrhea in some people. Although rare, excessive intake can cause thirst, low blood pressure, drowsiness, muscle weakness and slowed breathing. Be aware that magnesium can interact with certain supplements and drugs (See Concerns and Cautions).
You must be a member to get the full test results along with ConsumerLab.com recommendations and quality ratings. You will get results for 21 magnesium and magnesium-combination supplements selected by ConsumerLab.com and 10 others that passed testing in its voluntary Quality Certification Program.
In this comprehensive review, you'll discover:
Which magnesium and calcium/magnesium supplements failed our tests and which ones passed
CL's Top Pick among the magnesium supplements based on form, quality and dose
The pros and cons of different forms of magnesium, including magnesium aspartate and orotate, magnesium citrate, magnesium chloride, magnesium lactate and lactate dihydrate, magnesium oxide and magnesium-L-threonate
How to get adequate magnesium from food
The causes and symptoms of magnesium deficiency
How much magnesium to take to treat or prevent magnesium deficiency and other conditions
The evidence for and against using magnesium supplements for restless leg syndrome, leg cramps, migraines and more
Potential drug interactions and side-effects of magnesium supplements
More magnesium supplement results to be added in coming weeks, including combination products with calcium, boron, vitamin D and vitamin K
Magnesium Supplements: What You Need to Know -- Dr. Tod Cooperman
Learn More About Magnesium Supplements
ConsumerLab.com Answers -- for Magnesium Supplements Review (Including Calcium, Vitamins D & K, and Boron)
Question: Some websites are highly critical of magnesium stearate, which is in many supplements. Is this substance toxic and should I avoid it? Get the answer >>
Question: Sometimes my powdered supplements get clumpy. Should I be concerned? Get the answer >>
Question: What is the benefit of magnesium orotate compared to other forms of magnesium? Get the answer >>
Question: Are supplements with amino acid chelated minerals better than those with other forms of minerals? Get the answer >>
Question: Are enteric coated supplements better than non-enteric coated ones? Get the answer >>
Question: Do magnesium supplements, like Magtein, help memory or protect against Alzheimer's disease? Get the answer >>
Question: Can taking certain forms of potassium, such as potassium citrate, reduce my chances of getting kidney stones? I've read a study that says it can, but it's unclear how much I should take. Get the answer >>
Question: I have low blood pressure. Are there any supplements I should avoid? Get the answer >>
Question: Which is the best form of magnesium to take - one that contains the most magnesium and is best absorbed? Get the answer >>
Question: How can the Recommended Daily Allowance (RDA) for magnesium be higher than the Upper Tolerable Intake Level (UL)? That is, how can an amount which is healthful also put you at risk for harm? Get the answer >>
Question: Do any supplements help for irritable bowel syndrome (IBS)? Get the answer >>
Question: Are there negative interactions between the following supplements I take twice each day, as well as 60 mg of beta-sitosterol with dinner: Vitamin C (500 mg), CoQ10 (100 mg), grape seed extract (100 mg), fish oil (500 mg), vitamin D3/calcium/magnesium/zinc (200 IU/333 mg/113 mg/5mg)? Get the answer >>
Question: Help! How do I know how much magnesium I am actually getting from my supplement? The label says it contains 500 mg of magnesium "as magnesium citrate" -- but how much of that is magnesium and how much is citrate? Get the answer >>
Question: Which supplements reduce the risk of stroke? Which increase the risk of stroke? Get the answer >>
Question: Which supplements can help with indigestion and/or heartburn? Get the answer >>
Question: Do any supplements help reduce the symptoms of premenstrual syndrome (PMS)? Get the answer >>
Question: I was surprised when my doctor told me to stop taking supplements because my kidney function was low. But after stopping the supplements, my kidney function returned to normal. Can taking a lot of supplements really damage the kidneys? Get the answer >>