I am re-posting this topic with some edits after MarkS78 asked about magnesium. I have made some edits.
I can't post all of the magnesiums on here so I am going to post the best and the ones never to take. I have done a lot of research into this over time. A general rule of thumb is that chelated magnesiums are best. However, 2 are poisonous in high quantities but still sold!
Magnesium Threonate - Considered to be the best form of magnesium. Helps with brain health and is believed to cross the Blood Brain Barrier (so it goes to the brain too!)
Magnesium Glycinate - Relaxation, Pain, and fatigue (symptoms and conditions) and brain health
Magnesium Malate - Muscle pain, fibromyalgia and chronic fatigue
Magnesium Taurate or Magnesium Orotate - Heart health and repair (repairs the heart somewhat over 6-12 months)
Magnesium Carbonate - Acid Reflux
Magnesium Chloride - Raise magnesium levels in those that have a low level of stomach acid (as seen in the elderly and in certain conditions)
Magnesium Hydroxide (Commonly known as Milk of Magnesia) - Antacid/ for Acid Reflux (do not use as a laxative)
Stay Away from:
Magnesium Oxide - Although it has a high magnesium content only 4% is absorbed so if you took 100mg you would actually be getting 4mg
Magnesium Sulfate - With the exception of Epsom salts it is useless
Magnesium Citrate - Laxative (I would avoid it in favour of Macrogols which is Movicol/Laxido or Docusate Sodium)
Magnesium Pidolate - Apart from raising magnesium levels, no health benefits
Magnesium Lactate - only raises magnesium levels
Magnesium Phosphate - antacid/laxative (do not use as laxative), not as good as Magnesium Hydroxide but if you cannot tolerate Magnesium Hydroxide then it is a suitable alternative as an antacid.
Magnesium Aspartate - NEUROTOXIC, if taken in large quantities this can lead to pain conditions and many brain conditions as it contains a neurotransmitter which in high enough quantities is deadly
Magnesium Ascorbate - NEUROTOXIC, same reason.
Any I haven't mentioned or any info you'd like feel free to ask
You shouldn't take more than 400mg of magnesium in supplements - it will tell you on the back of the label how much of it is the chelate e.g. Malic acid (in Magnesium Malate) and how much is magnesium). Do not exceed 400mg of magnesium without medical supervision.
WARNING: If you have Kidney Disease, myasthenia gravis, Atrial Fibrillation, a slow heart rate or a HIGH Magnesium Level- supplementation COULD make your condition worse. Be safe and talk to your doctor if you have any of the above conditions. I would always check with my doctor or a trusted pharmacist first.
I would recommend also taking a multivitamin, vitamin D and calcium at least. Vitamin D dose should be around 1000 IU (total, check how much is in other supplements you take) but can be higher or lower and you can figure out the best dose for you with blood tests from your doctor. It is better to take these supplements with a meal to increase their absorption. you could also supplement other vitamins, minerals etc. (e.g. omegas) but this will depend on what multivitamin you are taking.
For Vitamin D, the best vitamin D to take is Vitamin D3 (Cholecalciferol). Do not exceed 10,000IU of vitamin D (in any form) without medical supervision.
I need to research calcium and good multivitamins, two good multivitamins i am aware of are Forceval and WellMan/WellWoman Max. WellMan/WellWoman Max contain all the Vitamin D etc. you need and you have the added benefit of calcium and omegas
You can send me questions by PM or replying back :)