Bone Health
Not just a scaffold. Bones are living tissue in constant remodeling—old bone is broken down, new bone is built. This balance requires nutrients (calcium, D, K2, magnesium), hormones (estrogen, testosterone, parathyroid), and mechanical stress (weight-bearing exercise). Osteoporosis is silent until a fracture.
Bone Remodeling
Osteoclasts (Break Down)
Cells that dissolve old bone. Release calcium into blood. Activated by PTH, low estrogen.
Osteoblasts (Build Up)
Cells that form new bone. Deposit calcium matrix. Stimulated by mechanical stress, vitamin D.
Healthy bone = balanced remodeling. Osteoporosis = breakdown exceeds building.
What Bones Need
Nutrients
- Calcium: The mineral matrix. 1000-1200mg/day.
- Vitamin D: Absorb calcium from gut. 40-60 ng/mL optimal.
- Vitamin K2: MK-7 form. Directs calcium to bone, away from arteries.
- Magnesium: Part of bone crystal. Activates vitamin D.
- Protein: Bone matrix is 50% protein (collagen).
Hormones & Stimulus
- Estrogen: Inhibits bone breakdown. Menopause = rapid loss.
- Testosterone: Anabolic for bone. Low T = bone loss in men.
- Growth hormone: Promotes bone formation.
- Mechanical stress: Weight-bearing exercise builds bone.
- PTH balance: Chronic elevation = bone loss.
What Depletes Bones
Inactivity
No mechanical stress = no signal to build. Astronauts lose bone rapidly.
Low Estrogen
Menopause accelerates loss. Up to 20% in first 5 years post-menopause.
Corticosteroids
Prednisone rapidly depletes bone. One of biggest drug-induced causes.
Excess Alcohol
Toxic to osteoblasts. Impairs calcium absorption. Falls also more likely.
Smoking
Accelerates bone loss. Impairs healing. Major osteoporosis risk factor.
High Cortisol
Chronic stress breaks down bone. Same mechanism as corticosteroid drugs.