It's the wonder vitamin of the moment, and with good reason: Getting enough vitamin D seems to protect against just about everything, from cancer and depression to heart disease and an earlier death. When it comes to the sunshine vitamin, you've heard it all before—or so you think. It turns out there are a handful of lesser-known reasons you'll want to guarantee you get your daily dose. Which, by the way, is frustratingly tricky to pin down. The Institute of Medicine currently recommends men and women get 600 IU of vitamin D a day, but recent research suggests those guidelines are way too low—one possible reason about 42% of American adults seem to be vitamin D deficient. The IOM currently lists 4,000 IU a day as the highest amount of vitamin D you could take and still be safe, but we might need more like 7,000 to truly reap the vitamin's biggest benefits. Until science figures it out, let the following benefits inspire you to get some sensible sun exposure, eat more sources of naturally occurring vitamin D, and consider a supplement. 1. Vitamin D makes you less likely to fall at home. One in three older adults living at home will take a spill each year. Butvitamin D supplements seem to help reduce that risk. In a small study of homebound adults between the ages of 65 and 102 who get some grub from Meals on Wheels, half were given a monthly allotment of vitamin D supplements that averaged out to 3,300 IU per day and half were given a placebo. Over the 5-month study period, the supplement increasedvitamin D levels in their blood from "insufficient" (defined as less than 20 ng/mL) to "optimal" (defined as greater than 30 ng/mL) in 29 of the 34 participants. Compared with the people who got a placebo, those takingvitamin D had about half as many falls at home over the same time period, possibly because of the benefits of vitamin D for muscle performance, the researchers write. 2. It may ward off vision damage. The main reason our vision starts to slip after 50 is because of what's called age-related macular degeneration, a slow-progressing blurriness that starts near the center of the eye and impedes our ability to see clearly straight ahead. Your chances of ending up with AMD are governed mostly by your age, race, and genes—aka, it's pretty much out of your control, although staying generally healthy by avoiding smoking, working up a sweat on the regular, and eating your kale might help you keep your crystal-clear sight. However, a recent study suggests that maintaining optimal vitamin D levels can also help, even if the genetic cards are stacked against you. University of Buffalo researchers crunched the numbers from 913 postmenopausal women who were already part of a Women's Health Initiative study called the Carotenoids in Age-Related Eye Disease Study, or CAREDS. Of those 913 women, 550 had adequate levels of vitamin Dand 88 were deficient. The women who fell into the latter category had a higher risk of developing AMD—as much as 6.7 times higher if they also carried a specific form of high-risk genes—than women with sufficient vitamin D. 3. It might stop that weird muscle spasm you've been trying to ignore. One of vitamin D's crucial roles in our bodies is keeping our muscles functioning and strong by helping them absorb calcium. While there's a lot we don't know about the little muscle abnormalities we call cramps, spasms, and twitches, it seems like not getting enough vitamin D may be one cause of those annoyances. 4. It can slow weight gain. PHOTOGRAPH BY BLINDTOY99/GETTY IMAGES It's another one of Mother Nature's cruel tricks that it's oh-so-easy to gain weight without even noticing after a certain age. But having enoughvitamin D might help slow that process. In a Journal of Women's Healthstudy of more than 4,600 women 65 or older, those with insufficientvitamin D levels gained 2 more pounds over 4.5 years than those with enough D. (Lose up to 15 pounds WITHOUT dieting with Eat Clean to Get Lean, our 21-day clean-eating meal plan.) 5. It can help ease fibromyalgia pain. As if the chronic muscle and joint pain, all-encompassing fatigue, and associated depression and anxiety of fibromyalgia weren't enough, add to the complexity of the disease the difficulty many patients have getting a diagnosis to begin with. So hearing that something as comparatively simple as supplementing with vitamin D can bring relief might be welcome news. A small 2014 study gave women either vitamin D supplements or a placebo for 20 weeks, then monitored the women for another 24. Even after the treatment ended, the women who had been taking vitamin D noted less pain. While it's far from a cure—and it did nothing for mood symptoms—it's something. 6. It can keep your cholesterol in check after menopause. People who get enough vitamin D are at a decidedly lower risk of heart disease, but postmenopausal women get an additional benefit when they're up to date on their D: healthier cholesterol. In a 2014 study of 600 women, researchers found that after 2 years of taking 1,000 milligrams of calcium and 400 IU of vitamin D daily, women dropped 4.5 mg/dL in their LDL or "bad" cholesterol, compared with women who were given a placebo. Among the women who took the supplements, those who ended the study with higher levels of vitamin D in their blood also benefited from higher levels of HDL or "good" cholesterol. 7. It can reduce your risk of uterine fibroids. Uterine fibroids are noncancerous tumors that grow in the uterus walls. Because they can grow as big as a grapefruit(!), they can be unfathomably painful and uncomfortable for some women, while other women with smaller fibroids don't even notice them. They seem to be related to hormones and an unlucky genetic hand. But a 2013 study found thatvitamin D might also play a role. Among 35- to 49-year-olds, those with sufficient vitamin D levels had about a 32% lower chance of developingfibroids than those with insufficient vitamin D. The vitamin had previously been shown to slow fibroid growth in animal studies, but this research was the very first to examine the effect of vitamin D on fibroidsin humans. Source
