Bone

Bone is living mineralized tissue, constantly remodeled by osteoblasts (building) and osteoclasts (resorbing) under mechanical load and hormonal control. Collagen forms about 30% of bone mass, with calcium and other minerals making up most of the rest.

Thyroid drives renewal, not just resorption

Ray Peat argued that adequate thyroid hormone supports bone renewal, and that the bone-breakdown markers that rise with active thyroid function reflect healthy turnover rather than pathological loss:

T3 increases the formation of bone.

— Ray Peat

The thyroid hormone supports bone renewal, and increases indicators of bone breakdown in the blood.

— Ray Peat

Calcium itself has effects beyond structural mineral supply: Peat described it as lowering the same stress-adjacent signals (adrenaline, parathyroid hormone, prolactin) that drive bone loss:

Calcium activates mitochondrial respiration, and lowers adrenaline, parathyroid hormone, and prolactin.

— Ray Peat

Vitamin K2 specifically stimulates production of osteocalcin and osteonectin, two of the key non-collagen bone proteins, while progesterone and estrogen act oppositely on the carbonic-anhydrase pathway involved in bone remodeling.

Practice

Calcium, vitamin K2, vitamin D, adequate protein, and progesterone/estrogen balance all matter; weight-bearing movement helps when the body is adequately fueled to use it.

See also

• Calcium
• Vitamin K2
• Vitamin D
• Parathyroid
• Thyroid
• Progesterone