It's easy to think of vitamins as a form of no-hassle health insurance: pop enough of them and you won't fall victim to colds or the flu, plus you'll have extra energy even if you're not eating right or sleeping enough, right? And if you've got diabetes, you may be tempted to pop some extras.

But do diabetics really need more vitamins than non-diabetics?

"The short answer is no," says Shahla Nader-Eftekhari, MD, a professor of internal medicine at The University of Texas Health Science Center at Houston (UTHealth.) "There is no particular need to take extra vitamins."

That said, she adds, some data suggests that one of the drugs used for diabetes, metformin, may lower vitamin B12 levels in the body. "It's not very common," she says. "But it's worth checking in with your doctor to see if your B12 levels should be monitored."

And, adds Nader-Eftekhari, Vitamin D may be prescribed to diabetics who take thiazolidinediones, drugs meant to decrease insulin resistance and lower blood sugar levels in Type 2 diabetics. This class of drugs has been linked with bone fractures in certain individuals, she says. "In this case, calcium and vitamin D can help," she explains. "But they help in an indirect way. It's not that people need them because they have diabetes, but because they need the extra vitamins since they are on these drugs."

Dosing yourself with extra Vitamin D without consulting a doctor is not recommended, though. This vitamin has been touted recently as a miracle vitamin that can do everything from promoting good bone health to preventing some cancers, explains Spyros G. Mezitis, MD, Ph. D., of Lenox Hill Hospital in New York City.

But he cautions against taking it unless you've had your vitamin D levels tested, and you know your levels are low. "We give vitamin D according to what the levels are in the patient's blood," he says.

Mezitis also recommends that diabetics be tested for a vitamin E deficiency if they have eye problems or high cholesterol. "You may need to take some extra Vitamin E if you are low," he says.

Whatever vitamins you and your health care provider decide you should take, it's important to take them at the right time, Mezitis says. Here's what you need to know:

  • To make sure you're absorbing as much of a particular vitamin as possible, take them at the right time, Mezitis says. Fat-soluble vitamins like D, E, and A should be taken right after meals for maximum absorption, he explains.
  • Water-soluble vitamins like vitamin C can be taken with or without food, he says.
  • The amount of a vitamin you actually absorb is affected by certain other medications and vitamins. "If you take calcium and Vitamin D with other vitamins when you are not eating, you don't absorb as much," Mezitis says. Ask your doctor when to take a particular vitamin so it won't be affected by medications.
  • Finally, ask your doctor about spacing doses of vitamins. If you've been told to take 1,000 milligrams of calcium per day, for instance, you may be instructed to split the dose in half. That's because the body doesn't absorb more than 500 milligrams of calcium at a time, Mezitis says.