Thanks Mike. My interest came from reading a article yesterday. Here's a copy and paste:
‘I take magnesium at night’
Dr David Clancy, 59
Lecturer in biogentorology at Lancaster University
“There’s a fair consensus that most people could benefit from more magnesium. I’ve been researching the delay of age-related illnesses for decades and, in 2005, I did an experiment with fruit flies and looked at a number of interventions to see if they correlated with longer survival. The one that stood out was done with magnesium. The fly strain that lived longest had highest magnesium and the ones that were shortest had lowest magnesium.
“I’ve been taking 1500mg of magnesium citrate every night since. The citrate form helps with absorption and taking it at night can be helpful because it can help with sleep. It’s also involved in 600 other bodily reactions, including helping potentially with exercise performance and mood regulation.
“Since that study, more research has linked magnesium levels with healthy ageing and longevity. Low magnesium intake is also linked to increased levels of inflammation, which plays a crucial role in ageing and chronic disease. One review of 11 studies found that magnesium supplements reduced levels of C-reaction protein, a marker of inflammation, in people with chronic inflammation. Magnesium is found in dark green leafy vegetables, nuts, seeds and wholegrains.
“I also take a vitamin D3 supplement. There is a tonne of evidence saying that it’s helpful for the immune system, for bones and the prevention of many chronic illnesses. My work hasn’t focused on it but the epidemiological evidence for it is strong. Plus, in Britain, the fact is, we just don’t get enough sunlight to provide all our vitamin D needs so most of us should be taking supplements.”
There's was also some suggestion that while magnesium is found in vegetables, the relatively poor quality of soil some veg is grown in leads to the veg taking up less magnesium than expected. I guess the answer is to aim for organic veg as much as possible if availability (and budget) allows for this.