Table 2.

Sample stability in the freezer

Sample stability—in the freezer, sample protected from light (−80°C)
Period	MK‐4 (ng/mL)	K1 (ng/mL)	MK‐7 (ng/mL)
Original value	1.004	1.051	1.320
After 1 mo	1.002	1.046	1.320
After 2 mo	1.000	1.043	1.318
After 3 mo	0.996	1.045	1.311