Nature Made K2 100 mcg Review

This product gives 100 micrograms of vitamin K2 a day, which is above the 90 micrograms that worked in a study. A 2022 pooled analysis of nine trials in 6853 postmenopausal women with osteoporosis found vitamin K2 raised spine and forearm bone density more than control, with more mild side effects but no serious ones ^[1]. Another 2022 pooled analysis of 16 trials in 6425 postmenopausal women also found better spine bone density, but fewer fractures showed up only after one study was left out ^[2]. A 2015 pooled analysis of 19 trials found the spine benefit in women with osteoporosis but not in women without it ^[3]. A 2025 pooled analysis found vitamin K2 improved most markers of bone turnover in women with osteoporosis, though it did not measure bone density or fractures ^[4]. In a three-year trial of 244 healthy postmenopausal women, 180 micrograms a day slowed bone loss at the spine and the hip neck, but not the total hip ^[5]. In a one-year trial of 311 adults, 90 micrograms a day reduced bone loss at the hip neck in postmenopausal women but not in men ^[6]. Not every trial found a benefit, and the evidence for fewer fractures is weak. Animal and cell studies are never counted.

Vitamin D is the main ingredient the panel discussed here, and most of the ten recommend it or use it themselves, mainly for immune health, bone strength, brain and mood, and general health or longevity. Doses vary: three of them take 5000 IU of the D3 form in the morning, while one says to take at least 10,000 IU daily in winter and another points to a figure near 8,895 IU. Several advise getting blood levels tested, with targets that range from about 40 to 100 depending on who is speaking. Common pairings are vitamin K2, magnesium, and dietary fat for better absorption, and one says to take it in the fall and winter when sun is limited. One panelist says there is no point in supplementing for most goals unless you are deficient, and no one reports stopping it.