Vitamin D & Calcium: Optimizing Bone Health Across the Lifespan

Vitamin D & Calcium: Optimizing Bone Health Across the Lifespan

These two nutrients work synergistically—calcium builds bone; vitamin D enables its absorption. Most adults fall short on both. Here's how to optimize intake at every life stage.

Vitamin D: Sources & Targets

• Sun: 10–30 min midday exposure (arms/legs), 2–3×/wk. Darker skin, higher latitude, winter, sunscreen ↓ synthesis.
• Food: Fatty fish (salmon, mackerel, sardines), UV-exposed mushrooms, fortified dairy/plant milks, egg yolks.
• Supplements: D3 (cholecalciferol) preferred. RDA: 600 IU (1–70 yr), 800 IU (71+). Many need 1,000–2,000 IU to reach 30–50 ng/mL. Test 25(OH)D.

Calcium: Sources & Targets

• Dairy: Milk, yogurt, cheese — highest bioavailability (~30%). 3 servings/day ≈ 1,000 mg.
• Plant-based: Fortified milks, tofu (calcium-set), kale, bok choy, broccoli, almonds, chia, white beans. Oxalates/phytates reduce absorption.
• Supplements: Calcium citrate (anytime) or carbonate (with food). RDA: 1,000 mg (19–50), 1,200 mg (51+ women, 71+ men). Split doses >500 mg.

Co-Factors Not to Ignore

• Magnesium (glycinate) — activates vitamin D, regulates calcium transport.
• Vitamin K2 (MK-7) — directs calcium to bone, away from arteries.
• Weight-bearing exercise — mechanical stimulus for bone formation.
• Protein — 1.0–1.2 g/kg/day for bone matrix.

Special Populations

• Postmenopausal women: accelerated loss → prioritize D, K2, Mg, resistance training.
• Vegans: fortified foods + supplements essential.
• Older adults: ↓ skin synthesis, ↓ intake, ↓ absorption → monitor.
• Glucocorticoid users: proactive bone protection.

Personalize with your clinician. Bone health is a lifelong investment—start today.