I’m seeing more and more of it and I am convinced that there is a relationship: significant boosts in HDL cholesterol from vitamin D supplementation.
To my knowledge this remains an undescribed and uncharacterized phenomenon. There have been several observers over the last two decades who have noticed that total cholesterol shows a seasonal fluctuation: cholesterol goes up in fall and winter, down in spring and summer; year in, year out. This phenomenon was unexplained but makes perfect sense if you factor in vitamin D fluctuations from sun exposure.
I have come across no other substantiating evidence about fluctuations of HDL. But I am convinced that I am seeing it. Replace vitamin D to a blood level of 50 ng/ml, and HDL goes up if it is low to begin with. If HDL is high to begin with, say, 63 mg/dl, it doesn’t seem to change.
But, say, starting HDL is 36 mg/dl. You take niacin, 1000 mg; reduce high-glycemic index foods like breakfast cereals, breads, cookies, bagels, and other processed carbohydrate foods; exercise four days a week; add a glass of red wine a day; even add 2 oz of dark chocolate. You shed 15 lbs towards your ideal weight. After 6 months, HDL: 46 mg/dl. Better but hardly great.
Add vitamin D at a dose of, say, 4000-6000 units per day (oil-based gelcap, of course!), and re-check HDL two or three months later: 65 mg/dl.
I’ve seen it happen over and over. It doens't occur in everybody but occurs with such frequency that it’s hard to ignore or attribute to something else. What I’m not clear about is whether this effect only occurs in the presence of the other strategies we use to raise HDL, a “facilitating” effect, or whether this is an independent benefit of HDL that would occur regardless of whatever else you do. Time will help clarify.
We are tracking our experience to see if it holds up, how, and to what degree on a more formal basis. Until then, a rising HDL is yet another reason—-among many!-—to be absolutely certain your 25-OH-vitamin D3 level is at 50 ng/ml or greater.
How high is an ideal vitamin D blood level? If 50 ng is good, is 60 or 70 ng even better? Probably not, but there are no data. We have to wait and see. Unlike a drug that enjoys plentiful “dose-response” data, there are no such observations for vitamin D into this higher, though still “physiologic,” range.