By Addie Radandt
Most of us grew up knowing that vitamin D is good for our bones, but did you know it’s also a huge part of preventive health care? “Vitamin D deficiencies could increase the risk for certain cancers, like colon and breast cancer. We know that folks that are deficient in vitamin D have two times the risk of multiple sclerosis,” says Dr. Amanda Preimesberger, a family medicine physician at SSM Health.
Being deficient in vitamin D can also have an effect on mental health issues such as depression or dementia. Taking a supplement can help prevent those issues, but it’s still important to remember that vitamin D isn’t a cure-all. According to Preimesberger, if you’re someone who suffers from these diseases but your vitamin D levels are already normal, there really isn’t evidence that taking an extra supplement will make much of a difference.
“What we know primarily is the effects of low vitamin D. The hard part is that it’s less clear what the optimal level is,” she says.
The only way to know what your vitamin D levels are is through blood testing, but unless you are already at risk of being deficient, you generally do not need to be tested. “Always talk to your physician,” Preimesberger says, “It’s a pretty expensive test that’s not always covered well by insurance.”
Getting 15-20 minutes of sun exposure a day is an effective way of getting enough vitamin D, but too much sun can increase your risk of skin cancer. In order to minimize your risk but still get a sufficient amount, Preimesberger highly recommends that everyone take a vitamin D3 supplement. Vitamin D3 is the preferred form because it’s the most easily absorbed and has the longest shelf-life. Those aged 1-70 should be getting around 600 units a day; those 71 and older should be getting around 800 units a day, while infants should be getting around 400 units a day, says Preimesberger.
“For infants, we recommend supplementation because they’re not out in direct sunlight often and there’s not a lot of vitamin D in breast milk,” she says. Although formula is fortified with the vitamin, it still may not be enough. “We know that by supplementing infants with vitamin D we can lower their risk for things like Type 1 diabetes by as much as 30% later in life,” states Preimesberger.
However, she also warns about the dangers of taking an excessive amount of vitamin D. Although some recent health trends have been promoting the sunshine vitamin as a universal panacea, Preimesberger says that there’s a downside in getting too much. “Vitamin D is a fat soluble vitamin, so more is not necessarily better if you’re already normal, because your body can store it long term in fat tissues, and it can actually become toxic.”
