Scientists in 2016 found that magnesium in cells helps their internal "timekeeping." Our bodies have their own personal clocks, a set of internal rhythms that regulate when we feel sleepy and when we wake up through a cycle of hormones and other signals. They're called our circadian rhythms (otherwise known as "the body clock"), and they're what gets messed up if we're sleep deprived or jet-lagged. This clock is controlled by a "master clock" in the brain and mirrored by others all through the body.

Magnesium, according to the 2016 study, is vital for cells to maintain their internal clocks. Levels of magnesium rise and fall over a 24-hour period, regulating when we sleep and when we wake up, and disrupting those levels means messing up the body clock pretty quickly.

The magnesium in your body acts as a relaxant, encouraging muscle fibers to stay loose rather than contract. "Magnesium acts as a natural calcium blocker to help muscles relax," explained Healthline in 2018. "In your muscles, calcium binds to proteins such as troponin C and myosin. This process changes the shape of these proteins, which generates a contraction. Magnesium competes with calcium for these same binding spots to help relax your muscles."

For this reason, magnesium is sometimes used to help out when it comes to preventing seizures, or uncontrollable contractions of muscles. Pregnant women with pre-eclampsia or eclampsia are often given magnesium sulfate to avoid seizures, wrote the Linus Pauling Institute at Oregon State University.

Magnesium levels in the body fluctuate in response to many different things — and it looks as if labor is one of those things. A famous 1994 study found that women in active labor had much less magnesium in their uteruses than women who weren't yet in labor, and boosting magnesium levels is a well-known way of trying to stave off pre-term labor; if you're at risk of giving birth far too early, you'll likely be given magnesium to try and stop the process.

A study in 2015 also found that being given magnesium during labor helped lower the risk of fever in mothers and complications in babies, including "floppy baby" syndrome, where infants have low muscle tone. The reasoning seems to be that slightly higher magnesium levels during labor can trigger the immune system and help women and babies fight off fevers and other nasties.

This is one of the weirdest things magnesium does in the body: it plays a role in how well you remember things. In 2004 MIT scientists discovered that maintaining magnesium levels could help people avoid memory loss in middle age, and ever since science has discovered new ways in which magnesium supports memory in the brain.

A study in 2010 found that magnesium plays a role in the plasticity of the synapses in your brain, helping them shift and adapt to new information, and that magnesium supplements boosted cognitive function overall.

A study in 2018 found that if you're getting your dose of vitamin D from sunshine every day, but aren't thinking about your magnesium levels, you might not be getting the full benefits of that sun. Magnesium, it turns out, is essential to synthesizing vitamin D into the body, and without good levels of magnesium, you're not as capable of getting your appropriate vitamin D dose.

The scientists behind the study wrote that it's "essential to ensure that the recommended amount of magnesium is consumed to obtain the optimal benefits of vitamin D." Time to go out and grab some leafy greens.

Magnesium is a building block for a lot of different things, including our bones. However, there's one potentially unexpected area in the body where it's part of the construction team: the chromosomes. A study in 2018 used new tools to show that levels of magnesium ions regulate how chromosomes "fold" and organize themselves. Chromosome folding is essential for cell division, and we're still learning how the shapes and organization of chromosomes affect our health, but magnesium definitely appears to play a big role.

Cells in the body communicate with one another, and it turns out that magnesium is essential to making that happen. There's a cell-signaling molecule called cyclic adenosine monophosphate (cAMP), and the Linus Pauling Institute that magnesium is "required" for it to form. cAMP is a big deal in the body; it influences everything from the metabolism of sugar to brain function. It's also got a big role in the immune system, and when it increases it helps to kill off invasive microbes. Without magnesium to help create it, we'd all be much worse off.

Magnesium also has another role in the communications of the immune system. According to Nature in 2011, a transporter of magnesium called MAGT1, which helps to construct the T-cells that fight off threats to our immune system, is also responsible for "signals" that boost immune system response. Magnesium: it's involved in everything.

You definitely need to make sure you have enough magnesium in your body for all its functions, weird and otherwise. Make sure you have a diet full of healthy leafy greens, nuts and omega 3-rich fish, and if necessary talk to your doctor about having supplements.