A weekend post on Dr. Davis' Heart Scan Blog got me thinking about inflammation.
Inflammation is part of the body's response to injury or attack. It's not damage, per se. It's like bleeding. Bleeding isn't good, but bleeding indicates that you got cut, or suffered blunt trauma that induced internal bleeding. Say you stick your hand in a threshing machine and you start bleeding from the bloody remains of your hand. One "solution" is to pump up your blood-clotting factors until the bleeding stops, or even to pump up those factors so high that the next time you stick limbs into a threshing machine, the bleeding isn't so bad. Or, you could completely desanguinate yourself. (One good way to do that is to die and be embalmed.)
Another solution is to stop sticking your hands into threshing machines.
So if you've got inflammation going on, the "cure" isn't to cut down the inflammation, it's to find out what's causing the inflammation and go after that. Just like avoiding threshing machines is a far better solution than kicking up your blood-clotting factors, avoiding the things that cause "inflammation" is much better than reducing the inflammation itself through therapies such as ice or drugs.
If you've got gluten-induced intestinal inflammation, the cure is to stop eating gluten. And probably other grains, such as rice and corn, or other lectin-containing plant matter such as beans and nightshades (e.g. potatoes & tomatoes).
So Vitamin D reduces inflammation. (Specifically, supplementation with Vit D is correlated with reduced markers of inflammation.) This would be a good thing if it increases the body's ability to resist infection and damage, but probably a bad thing if it reduces inflammation by suppressing the body's response to infection and damage. Atherosclerosis is an inflammation process; does Vitamin D reduce the damage that instigates plaque formation, or does it reduce the amount of inflammation in response?