Bone Health

Why bone health matters for longevity

Your skeleton isn't the passive scaffolding most people assume it is. Bone is living tissue that constantly breaks down and rebuilds itself, a process called remodeling that replaces about 10% of your skeleton every year. This remodeling depends on a tight balance between osteoclasts (cells that dissolve old bone) and osteoblasts (cells that lay down new bone). When that balance tips toward breakdown, you lose bone faster than you build it. Bone mass peaks around age 30. After that, everyone loses roughly 0.5-1% per year, with women losing up to 2-3% annually during the first five to seven years after menopause due to falling estrogen levels ^[1].

Fractures from weakened bones aren't just painful inconveniences. A hip fracture in someone over 65 carries a one-year mortality rate of roughly 20-30% ^[2]. Even vertebral fractures that don't require surgery reduce mobility, increase chronic pain, and accelerate the loss of independence. A 2021 study of people aged 90 and older found that those who maintained better bone health had fewer hospitalizations and longer lifespans, suggesting that skeletal integrity is a genuine longevity marker, not just a quality-of-life issue ^[3].

Bone quality goes beyond density

Bone mineral density (measured by DEXA scans) gets most of the attention, but density alone tells only part of the story. About half of age-related hip fractures occur in people with clinically normal bone density ^[4]. That's because bone strength also depends on collagen matrix quality, microarchitecture (the internal lattice of trabecular bone), mineralization patterns, and the rate of bone turnover. Collagen makes up over 90% of the organic bone matrix and provides the flexibility that prevents bones from being brittle like chalk. As you age, osteocyte function declines, collagen cross-links accumulate damage, and microcracks repair more slowly ^[4].

This is why a comprehensive approach to bone health targets both mineral content and tissue quality, not just a single DEXA T-score number.

Exercise: the strongest stimulus for bone

Bones adapt to mechanical loading. Put simply, they get stronger where you stress them. The most effective exercises for bone health are those that create high-impact forces or heavy resistance. A 2023 systematic review and meta-analysis of randomized controlled trials found that moderate- to high-impact exercise improved trabecular bone density at the distal tibia and cortical thickness at the proximal femur ^[5]. Resistance training with heavy loads (above 70% of your one-rep max) provides the strongest osteogenic stimulus.

Regular walking, despite being frequently prescribed, produces forces too low to meaningfully slow bone loss ^[6]. You need activities that challenge your skeleton: jumping, running, stair climbing, and progressive weightlifting. For postmenopausal women specifically, a 2025 network meta-analysis of 55 RCTs found that multicomponent training (combining resistance and impact exercise) was the most effective approach for improving femoral neck bone density ^[5].

Nutrition for building and keeping bone

Calcium and vitamin D are the most studied nutrients for bone, and the data support their combined use. A meta-analysis from the National Osteoporosis Foundation including over 30,000 participants found that calcium plus vitamin D supplementation reduced total fracture risk by 15% and hip fracture risk by 30% ^[7]. For most adults, 1,000-1,200 mg of calcium daily (from food and supplements combined) and 1,000-2,000 IU of vitamin D3 is a reasonable target.

But calcium and D aren't the full picture. Vitamin K2 (particularly the MK-7 form) activates osteocalcin, the protein that directs calcium into bone rather than into artery walls. Magnesium is needed to convert vitamin D into its active form. Protein provides the amino acids for collagen synthesis, and a 2017 meta-analysis found that higher protein intake had a protective effect on lumbar spine bone density ^[8]. Vitamin C, zinc, boron, and silicon also support collagen formation and bone metabolism.

The gut-bone connection

An emerging area of research is the gut-bone axis. The gut microbiome influences bone metabolism through several pathways: it affects calcium and mineral absorption, modulates immune signaling that controls osteoclast activity, and produces short-chain fatty acids that support bone formation ^[9]. Aging shifts the gut microbiome composition in ways that may accelerate bone loss. Early evidence suggests that certain probiotics (particularly Lactobacillus and Bifidobacterium strains) can improve bone turnover markers, though large clinical trials in humans are still ongoing.

Lifestyle factors that weaken bones

Smoking activates osteoclasts and impairs blood supply to bone tissue. Heavy alcohol consumption (more than two drinks per day) disrupts bone remodeling and increases fall risk. Chronic inflammation from poor diet, sleep deprivation, or unmanaged stress elevates cortisol, which directly suppresses osteoblast function. Prolonged sedentary behavior removes the mechanical signals bones need to maintain themselves. Addressing these factors is as important as any supplement protocol.