NASHVILLE, Tenn. (KABC) --Vitamin K is needed by our bodies for blood clotting - and it's one of the first shots offered to newborns.
More parents are choosing to skip shots and not vaccinate their children, believing it's unhealthy and unnecessary.
Now, the CDC is reporting a surge of cases of life-threatening brain bleeds in babies who weren't vaccinated.
When the Shaker family had their twins, they decided against immunizations.
"Immunizations don't seem very natural, so I just wanted to stay away from them at least for a year," said Melissa Shaker, the mother.
Two months after bringing the boys home, baby Silas turned very pale.
"He looked like he was dying white. It was scary," Melissa said.
"One of the first questions that was asked of her in the hospital was 'Did you have, did you get the vitamin K shot?'" said Mark Shaker, the father.
The Shakers hadn't. Silas had vitamin K deficiency and suffered multiple brain bleeds.
Typically, the blood clotting disorder only affects one in 100,000 babies, but Silas is one of seven cases Vanderbilt doctors have seen in the last year.
"Had we known some of these things, we could have made smarter decisions," Mark said.
"Thankfully he was one of the cases that we'd seen after we'd already seen a couple of cases, and so we gave vitamin K immediately to this child," said Robert Sidonio, Jr. MD, MSC, pediatric hematologist, of Vanderbilt University.
Sidonio believes the numbers could surge in the future because of the trend of parents refusing immunizations.
"Probably somewhere in the range of 1 in 100 to 1 in 1,000 kids will develop this," he said.
While doctors were able to stop the bleeding in Silas, he has to take medication for seizures and he's in physical therapy to retrain his left side.
"Only time will tell. You know, will he respond to therapy? Will there be any other residual effects of this?" Mark said.
To be safe, Silas' twin Abel was also treated and is doing fine.
Sidonio says many parents have declined the vitamin K shot because of a single study circulating on the Internet linking it to leukemia. He says at least 10 studies since then have shown there is absolutely no link.