Maybe worms don’t get sunburns, but they appear to benefit from vitamin D, which can extend their normal 20-day lifespans.

Postdoctoral researcher Karla Mark, who has worked in Gordon Lithgow’s lab at Novato’s Buck Institute for Research on Aging since 2007, studies the effect of vitamin D on C. elegans roundworms. She is preparing an article about their findings for submission to scientific journals.

“Vitamin D3 extends median lifespan in the worms by 30 percent to 40 percent,” Mark said. “It’s pretty significant. They thrive. They live longer. It’s dramatic, thrilling. There are so many things to ask. It is a brand new field, a very interesting field.”

She replicated the findings in three experiments in the lab. Vitamin D3 is normally created in people when sunlight lands on the skin.

“If you feed the worms vitamin D,” Mark said, “they can metabolize this to the bioactive form (1,25-dihydroxy). They don’t have to get sunlight. Vitamin D suppresses the accumulation of insoluble proteins” having multiple functions “from cytoplasm to mitochondria,” and common to aging in worms as well as humans.

The bioactive form of vitamin D binds to receptors in every cell in the body, Mark said. In worms, there are 284 potential vitamin D receptors. She seeks to identify precisely where the vitamin binds. Proteins affected by vitamin D can also help maintain the “scaffolding” structure of bones, which also declines in aging.