- In the normal aging process, protein homeostasis is disturbed resulting in the accumulation of toxic insoluble protein aggregates.
- A new study in nematode worms, shows that vitamin D suppressed protein insolubility in the worm and prevented the toxicity.
- Vitamin D engaged with known longevity genes, extended median lifespan by 33% and slowed the aging-related misfolding of hundreds of proteins in the worm.
It is known that vitamin D plays and important role in regulating calcium absorption and promoting bone growth.
‘Vitamin D influences longevity genes to increase lifespan and prevents the accumulation of toxic proteins linked to many age-related diseases like Alzheimer’s disease, Parkinson’s as well as type 2 diabetes.’
AdvertisementThe research which was conducted at the Buck Institute and and published in Cell Reports explains that vitamin D has much wider effects when tested in the nematode worm, C. elegans.
This study may explain why vitamin D deficiency has been linked to breast, colon and prostate cancer, as well as obesity, heart disease and depression.
"Vitamin D engaged with known longevity genes - it extended median lifespan by 33% and slowed the aging-related misfolding of hundreds of proteins in the worm," said Gordon Lithgow, PhD, senior author and Buck Institute professor. "Our findings provide a real connection between aging and disease and give clinicians and other researchers an opportunity to look at vitamin D in a much larger context."
The study shines a light on protein homeostasis, the ability of proteins to maintain their shape and function over time.
The protein homeostasis is disturbed with normal aging often resulting in the accumulation of toxic insoluble protein aggregates implicated in a number of conditions, including Alzheimer's, Parkinson's and Huntington's diseases, as well as type 2 diabetes and some forms of heart disease.
"Vitamin D3, which is converted into the active form of vitamin D, suppressed protein insolubility in the worm and prevented the toxicity caused by human beta-amyloid which is associated with Alzheimer's disease," said Lithgow. "Given that aging processes are thought to be similar between the worm and mammals, including humans, it makes sense that the action of vitamin D would be conserved across species as well."
"Vitamin D3 reduced the age-dependent formation of insoluble proteins across a wide range of predicted functions and cellular compartments, supporting our hypothesis that decreasing protein insolubility can prolong lifespan."says Karla Mark, PhD, post-doctoral candidate at Buck Institute.
"We've been looking for a disease to associate with vitamin D other than rickets for many years and we haven't come up with any strong evidence," said Clifford Rosen, MD, the director of the Center for Clinical and Translational Research and a senior scientist at the Maine Medical Center Research Institute studying osteoporosis and obesity. "Now we're talking about something very different and exciting."
"This work is really appealing and challenging to the field," said Janice M. Schwartz, MD, a professor of medicine and bioengineering and therapeutic sciences the University of California, San Francisco, and a visiting research scientist at the Jewish Home in San Francisco.
The Institute of Medicine's (IOM) recommends a daily intake of 600 International Units (IU) for people between 1 and 70 years old, and 800 IU daily for those older.
Excess vitamin D can raise blood levels of calcium which leads to vascular and tissue calcification, with subsequent damage to the heart, blood vessels and kidneys.
Researchers Rosen and Schwartz agree that the costs of universal testing for vitamin D levels would outweigh the benefits.
The recommended universal supplementation of vitamin D should be between 800 - 1000 IU daily for adults.
Schwartz says older adults may be particularly prone to vitamin D deficiency because the skin's ability to manufacture vitamin D from sun or UV light exposure declines with age, adding that the elderly are less likely to spend time in the sun.
Others prone to vitamin D deficiency include those with darker skin and those who live in higher latitudes where the sun's angle is low in the sky.
Senior author Lithgow plans to test vitamin D in mice to measure and determine how it affects aging, disease and function -- and he hopes that clinical trials in humans will go after the same measurements.
"Maybe if you're deficient in vitamin D, you're aging faster. Maybe that's why you're more susceptible to cancer or Alzheimer's," he said. "Given that we had responses to vitamin D in an organism that has no bone suggests that there are other key roles, not related to bone, that it plays in living organisms."