Illustration by Elena Scotti/Fusion

Vitamin D has been said to help fight cancer and the common cold, and even prevent early death. The latest study, published in Psychiatry Research, adds to the body of research that suggests the vitamin may improve with our mental health as well.

After analyzing 185 women for five-week intervals, researchers from the University of Oregon found that participants with lower levels of vitamin D reported more symptoms of depression, leading them to believe that the vitamin could be key in preventing and treating the disorder.

Our bodies make our own vitamin D when exposed to the sun, but it's also found in certain foods and available as a supplement. Still, it's estimated that a billion people worldwide still don't get enough of it (the Institute of Medicine recommends 600 IU per day). Behold this list of what vitamin D may do for our bodies, and be inspired to up your intake today.

1. Vitamin D may decrease your risk of early death.

Perhaps the biggest reason to get more vitamin D is that it has been linked to living longer. Researchers from the University of California San Diego School of Medicine reviewed 32 separate studies that analyzed vitamin D levels and human mortality rates—and they found that participants with lower levels were twice as likely to die prematurely.

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"The Institute of Medicine concluded that having a too-low blood level of vitamin D was hazardous,” said Cedric Garland, lead author of the study, in a press release. “This study supports that conclusion, but goes one step further … [associating] low vitamin D with risk of premature death from all causes, not just bone diseases."

2. Vitamin D may help fight depression.

As we mentioned earlier, low levels of vitamin D have been linked to depression. Along with the latest research, a study from 2012 found that upping vitamin D levels in clinically depressed women with low levels of the vitamin improved their symptoms—without any change in their anti-depressant medication. The women in the study were given vitamin D supplements over the course of eight to 12 weeks, until their D levels were back to normal. Afterward, in some cases, the supplements improved the women's diagnosis from "severe" to "mild" or even "minimal."

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3. Vitamin D may help prevent the flu.

If everyone started getting more vitamin D, flu season might be more bearable. A study out of Japan found that the vitamin may help ward off the viral infection. Here's what they discovered: Over the course of four months, researchers gave one group of school-aged children (i.e. germ spreading machines) vitamin D supplements and another group placebos. At the end of the study, the vitamin D group was 40 percent less likely to get the flu.

4. Vitamin D may increase survival rates in cancer patients.

Another study from the University of California San Diego School of Medicine found that breast cancer patients with high levels of vitamin D were twice as likely to survive compared to patients with lower levels. Researchers came to this conclusion after analyzing the results of five separate studies that included 4,443 breast cancer patients. According to the researchers, "Vitamin D metabolites increase communication between cells by switching on a protein that blocks aggressive cell division." Uncontrolled cell division is what makes cancer spread.

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Several other studies have found that vitamin D may be helpful in preventing some cancers as well, specifically colorectal cancer.

5. Vitamin D may give you strong bones, which helps prevent osteoporosis.

Vitamin D may be best known for it's role in making your bones strong, by helping your body absorb calcium. Numerous studies have shown that low levels of vitamin D can lead to osteoporosis and osteomalacia (calcium-depleted bones). On the flip side, increasing vitamin D can help improve bone health: In a study of 40,000 elderly people, researchers found that high intakes of vitamin D supplements—of about 800 IU per day—reduced hip and non-spine fractures by 20 percent.

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6. Vitamin D deficiency may lead to heart disease.

One easy way to prevent against heart attacks is to get more vitamin D. Studies have shown that vitamin D deficiency is linked to heart disease, heart failure, and early cardiac death. The heart even has specific receptors for vitamin D.

In one study, researchers measured vitamin D levels in 18,225 men aged 40 to 75 years—then followed up with them 10 years later. Those with lower levels of vitamin D were twice as likely to have suffered from a heart attack.

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7. Vitamin D may help prevent diabetes.

Giving your child vitamin D supplements early on could prevent them from developing type 1 diabetes later in life. A study from Finland followed 10,000 children from birth. Those who regularly received vitamin D supplements during infancy had a nearly 90 percent lower risk of developing type 1 diabetes. And in a meta-analysis of five separate studies, researchers came to the same conclusion, finding that risk of "type 1 diabetes was significantly reduced in infants who were supplemented with vitamin D compared to those who were not supplemented."

What about type 2 diabetes (which accounts for 90 to 95 percent of all diagnosed cases of diabetes)? Well, a study published this year found that vitamin D deficiency was even more closely linked to type 2 diabetes than obesity. Just one more reason to get some sun.

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8. Vitamin D may help prevent respiratory infection.

You know that respiratory infection that just won't go away? The one that makes you cough for weeks? Vitamin D is here to help. In a study of 18,883 people aged 12 years and older, researchers examined the link between vitamin D and upper respiratory tract infections (URTI). They found that those with lower levels of vitamin D were more prone to infection—even after controlling for variables like smoking, weight, season, and asthma.

A separate study also found that vitamin D deficiency predisposes children to respiratory infections, while getting the recommended dose of vitamin D can boost the immune system's response to infection.

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9. So vitamin D is a magic cure-all?

Not exactly. Many studies have found links between vitamin D levels and a range of health benefits, but it's not quite a cure for everything that ails you.

"Our understanding of what vitamin D does in our bodies (and how much we need) is still in its infancy," Catherine Price, author of the book Vitamania: Our Obsessive Quest For Nutritional Perfection, told Fusion. "All health claims should, at this point, be taken with a big grain of salt."

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Of course, as Price points out, it can't hurt to up our vitamin D intake, given that many of us go months without seeing the sun. "No one knows for sure how much vitamin D we each need, but considering our tendency to cover up with clothing in the winter and use sunscreen in the summer, many of us likely don't make enough," she said. "Many experts recommend taking a supplement to hedge our bets."

Taryn Hillin is Fusion's love and sex writer, with a large focus on the science of relationships. She also loves dogs, Bourbon barrel-aged beers and popcorn — not necessarily in that order.