Calcium
50-90% of US adults are deficient in calcium; it is essential for bone mineral density alongside vitamin D.
Why It Matters for Longevity
50-90% of US adults are deficient in calcium; it is essential for bone mineral density alongside vitamin D. Calcium is the primary structural component of bone and teeth (hydroxyapatite); also required for muscle contraction, nerve signal transmission, and blood clotting cascades.. Calcium should be obtained from vegetables, legumes, and small fish (e.g., canned sardines with bones), with periodic multivitamin use every 2-3 days as a fallback. Whole-food sources provide better bioavailability due to accompanying cofactors; small fish and legumes deliver calcium without the saturated fat of dairy.. Higher vitamin D and calcium intake combined reduced hip fracture risk by up to 26% in adults over 65; calcium alone showed minimal benefit without adequate vitamin D, confirming the critical synergy emphasized in the Longevity Diet. (Bischoff-Ferrari et al., JAMA (2005) — PMID 15870411) Meta-analysis of 11 RCTs found that calcium supplements (without vitamin D) were associated with a 30% increased risk of myocardial infarction, cautioning against isolated high-dose calcium supplementation and supporting the book's preference for dietary sources. (Bolland et al., BMJ (2010) — PMID 20671013)
How to Use It
Pairs well with vitamin-d, sardines, black-beans. Use as a nutrient in your daily meals according to the Longevity Diet guidelines.
What to Pair It With
| Ingredient | Why | Tradition |
|---|---|---|
| vitamin-d | See synergies | The Longevity Diet |
| sardines | See synergies | The Longevity Diet |
| black-beans | See synergies | The Longevity Diet |
| kale | See synergies | General nutrition |
Synergies
- Vitamin-D (synergy): Vitamin D (as calcitriol) directly upregulates intestinal calcium transport proteins (TRPV6, calbindin-D9k), increasing calcium absorption by 30-80%; both are required for bone mineral density maintenance. - Magnesium (synergy): Magnesium is required for parathyroid hormone function; deficiency impairs the body's ability to regulate calcium metabolism and mobilize calcium appropriately. - Vitamin-K2 (complement): Vitamin K2 activates osteocalcin and matrix GLA protein, directing calcium to bones rather than arteries, reducing the cardiovascular risk associated with high calcium intake.
Flavor Profile
Category: micronutrient.
The Science
- Bischoff-Ferrari et al., JAMA (2005) — PMID 15870411: Higher vitamin D and calcium intake combined reduced hip fracture risk by up to 26% in adults over 65; calcium alone showed minimal benefit without adequate vitamin D, confirming the critical synergy emphasized in the Longevity Diet. - Bolland et al., BMJ (2010) — PMID 20671013: Meta-analysis of 11 RCTs found that calcium supplements (without vitamin D) were associated with a 30% increased risk of myocardial infarction, cautioning against isolated high-dose calcium supplementation and supporting the book's preference for dietary sources. - Tai et al., Current Osteoporosis Reports (2015) — PMID 25990339: Dietary calcium from plant sources (legumes, leafy greens, fortified foods) is associated with improved bone mineral density without the cardiovascular risks of high-dose calcium supplements, supporting whole-food calcium strategies for healthy aging. - Book claim (high confidence): 50-90% of US adults are deficient in calcium; it is essential for bone mineral density alongside vitamin D. - Book claim (high confidence): Calcium should be obtained from vegetables, legumes, and small fish (e.g., canned sardines with bones), with periodic mu
Key Nutrients
| Nutrient | Per 100g | Notes |
|---|---|---|
| Calcium (elemental) | Varies by food source; canned sardines with bones ~382 mg, kale ~254 mg, cooked black beans ~27 mg | Bioavailability ranges from ~5% (spinach, high oxalate) to ~32% (milk) to ~60% (kale, low oxalate); fractional absorption increases when intake is low. |