NatureBell Vitamin K Complex (K1 + K2 as MK-4 & MK-7) 2,600mcg Per Serving, 300 Coconut Oil Softgels Review

Each serving gives 1,500 micrograms of vitamin K1 and 1,100 micrograms of vitamin K2 (as MK-4 and MK-7). Both are above the doses used in the studies. The strongest support is for vitamin K2. Pooled trials in women after menopause found it improved lower spine bone density ^[1][2]. The spine benefit showed up in women with osteoporosis but not in women without it ^[3]. Fewer fractures appeared only after one study was left out ^[1]. In a three year trial, 180 micrograms a day slowed bone loss in the spine and hip ^[4]. A one year trial found 90 micrograms a day reduced hip bone loss in women after menopause but not in men ^[5]. Vitamin K taken with vitamin D raised total bone density ^[6]. Vitamin K also raised markers of bone building ^[7]. Vitamin K1 is less certain. Trials found no change in bone density ^[8][9], though fewer women had fractures in one of them ^[9]. In pooled trials, vitamin K1 alone showed no clear gain ^[10]. Higher vitamin K1 from food was linked to fewer fractures in observational studies ^[11]. Animal and cell studies are never counted.

Vitamin K is the main ingredient here, and all ten panelists spoke about it: four use it, three recommend it, and three stay neutral, with none saying they stopped. Those who take it mostly name vitamin K2 and give doses of 90 to 100 mcg in the morning for general health, longevity or keeping levels up, while one recommends a much larger 40 to 45 milligrams daily for osteoporosis. The main reasons given are bone strength and steering calcium into bones rather than arteries, plus arterial and joint health, and one says K1 is tied to easy bruising. Several advise pairing it with vitamin D, and one names the MK-7 form while another notes K2 breaks down into MK-4 and MK-7. The only caution came from one panelist, who warned that some multivitamins carry too much of another mineral, and food sources like leafy greens, natto, liver and grass-fed butter were also mentioned.

Tier 2 holds because pooled trials of vitamin K2 in thousands of women after menopause show better spine bone density ^[1][2], and 96% of 1,380 reviews are positive. The vitamin K1 evidence the rules cited is weaker: its largest analysis looked at diet rather than supplements, and K1 alone showed no clear gain in pooled trials ^[10], so the grade rests on the vitamin K2 and overall vitamin K findings.

Combine with: Vitamin K works best for bone health alongside other nutrients that supply and direct calcium. Vitamin D3 (1,000-5,000 IU, based on blood levels) improves calcium absorption and drives production of osteocalcin, the vitamin K-dependent protein that binds calcium into bone. Calcium (from food or a citrate or microcrystalline hydroxyapatite supplement) supplies the building material, and magnesium (glycinate or citrate, 200-400 mg) supports vitamin D activation and bone mineral structure. Collagen peptides or type I collagen add to the bone matrix, and boron, zinc, and vitamin C support bone formation. Take the softgels with a fat-containing meal to improve absorption. People on a med or other meds should avoid vitamin K supplements unless their doctor approves and monitors them, since vitamin K directly counteracts these drugs.