I’ve had a genetic test done, after being told that I have significantly lower than average vitamin d levels it turned out I’m genetically predisposed to low vitamin d and b12 absorption. So I have to supplement significantly more than what is normal.
After doing so, my colds have been far less severe then in the past. What made me go to such lengths testing myself was that I thought I was doing everything right and yet got pneumonia two years in a row.
So aside from testing your blood serum levels you should consider a genetic test to see how well you absorb vitamin d. You may benefit from above average dosage (consult your dr. Ymmv)
After doing so, my colds have been far less severe then in the past. What made me go to such lengths testing myself was that I thought I was doing everything right and yet got pneumonia two years in a row.
So aside from testing your blood serum levels you should consider a genetic test to see how well you absorb vitamin d. You may benefit from above average dosage (consult your dr. Ymmv)