Vitamins
Vitamin D3 + K2
The gap most northern-winter blood panels actually show.
Why it earns a place
If you work indoors or live above roughly 37° latitude, you make very little vitamin D for months at a time. K2 is paired with it because they work together on calcium handling. This is one of the few supplements worth testing for.
Who it's for
Indoor workers, winter climates, darker skin tones, and anyone with a low blood result.
Who should skip it
Your levels already test in range, or you take a blood thinner (K2 interacts — ask your doctor).
Dose
1,000–2,000 IU D3 daily unless your doctor sets a different dose.
Timing
With a meal containing fat, for absorption.
Typical price
$15–$35
Common questions
How do I know if I need it?
A simple 25(OH)D blood test from your doctor. It's the only honest way to know.
Can I take too much?
Yes — vitamin D is fat-soluble and megadoses can be harmful. Stay in the normal range unless a doctor directs otherwise.
Educational information only, not medical advice. Talk to your doctor before starting any supplement, especially if you take medication, are pregnant, or are nursing. Some links are affiliate links.