After age 40, calcium from your bloodstream can settle in parts of your body. Damaged, inflamed or repaired arteries are more likely to attract calcium deposits. This process can start in your 20s, but your healthcare provider may not see it until there’s an amount large enough to show up on imaging. And most people in their 20s and 30s wouldn’t have a reason to get imaging.
Calcium deposits start small (.5μm or micron/micrometer) and grow to be larger than 3mm with plaque continuing to accumulate at the same time.
Researchers believe that microcalcification in the intimal layer starts when smooth muscle cells die.