09/22/2021
Vitamin D concentrations take about 10 weeks to achieve steady state; the point at which the amount of vitamin D in your blood will be constant based on whatever amount you're taking.
If you've managed to get some safe sun exposure throughout the late spring and summer, the goal heading into the fall and winter is to maintain whatever vitamin D concentration you have NOW.
Don't wait until late November, December or January to start supplementing....your vitamin D concentration will have decreased significantly and will take some time, several weeks, to get back up to a therapeutic level.
If you didn't get any sun exposure for whatever reason, you don't want to wait either...
Vitamin D is a potent immune system modulator, supports the production of natural 'antibiotics' called anti-microbial peptides such as cathelicidins (PMID 23065264, 19895218) & tempers inflammation (cytokine storm) (PMID 32876941, 33551489).
When it comes to dosing for the vast majority of adults, 1000 IU (25 mcg) isn't enough to reap the FULL benefits of vitamin D.
Note, there's really only one correct answer to the question "how much vitamin D3 should I take", which is
- whatever amount is needed for YOU to achieve an ideal blood concentration
This is why testing can help; it allows for a personalized dose but based on research, most adults need between 2000/3000 - 5000 IU (50-125 mcg) per day.
Luckily in Canada, Health Canada as taken baby steps towards FINALLY supporting Canadians when it comes to vitamin D and now allows supplements to have up to 2500 IU (62.5 mcg) per dose.
My only question: "what are you waiting for?"