There isn't a lot of medical data to back it up, but some research does show that magnesium deficiency
magnesium deficiency
Magnesium deficiency is an electrolyte disturbance in which there is a low level of magnesium in the body. It can result in multiple symptoms. Symptoms include tremor, poor coordination, muscle spasms, loss of appetite, personality changes, and nystagmus.
https://en.wikipedia.org › wiki › Magnesium_deficiency
may be behind some (not all) causes of gray hair. If this is the cause of your greying, then making sure your magnesium stores are optimal could stop or even reverse the greying of your hair.