Calcium-Rich Foods for Bone and Teeth Health

By Hugo Francisco de SouzaReviewed by Benedette Cuffari, M.Sc.

Introduction
What is calcium and why is it important?
Calcium-rich foods
Health benefits of calcium
Recommended intake and deficiency risks
Safety and excess intake
Conclusions
References
Further reading

Learn how calcium, vitamin D, and magnesium work in harmony to keep your bones strong, your muscles active, and your body thriving through every stage of life.

Image Credit: Tatjana Baibkova / Shutterstock.com

Introduction

Calcium is the most abundant mineral in the human body, as it constitutes 1–2% of total adult body weight. Over 99% of calcium is stored in the bones and teeth in the form of calcium hydroxyapatite (CaHA), with the small remaining fraction used during vascular contraction, muscle function, nerve transmission, and hormonal secretion.^1,2

According to recent global nutrition analyses, approximately 3.5 billion people consume less calcium than recommended dietary levels, contributing to a growing prevalence of deficiency-related skeletal issues worldwide. Calcium deficiency is prevalent among children, adolescents, and older adults, emphasizing the need for nutritional surveillance and targeted supplementation where required.^1,3

This article discusses the crucial role of calcium in maintaining optimal skeletal and dental health while identifying the best dietary sources of this mineral.

What is calcium and why is it important?

By adulthood, the body is estimated to contain about 1,200 g of calcium in women and 1,400 g in men. The human body maintains serum ionized calcium levels within a narrow range of 8.8–10.4 mg/dL, tightly regulated by parathyroid hormone (PTH), vitamin D, and calcitonin, which together maintain homeostasis using bone tissue as a dynamic reservoir.^1,2

When dietary calcium intake is insufficient, PTH stimulates bone resorption to maintain normal blood calcium levels, prioritizing neuromuscular and cardiac function. Chronic dietary inadequacy therefore accelerates age-related bone demineralization and loss of bone mass.^1,2

Bone undergoes continuous remodeling in which old bone is resorbed and new bone is formed from available calcium. Adequate intake is required to maintain density and structural integrity across the lifespan.²

Calcium also plays a vital role in muscle contraction, as ionized calcium released from the sarcoplasmic reticulum initiates interactions between actin and myosin filaments. In the nervous system, calcium influx into axon terminals triggers neurotransmitter release. Additionally, calcium functions as a cofactor for several blood-clotting enzymes, making it essential for hemostasis and wound repair.^1,2

Calcium-rich foods

Dairy products such as milk, yogurt, and cheese are the most concentrated and bioavailable natural calcium sources, with absorption rates averaging over 30%. Non-dairy animal sources, including canned sardines and salmon with bones, also provide substantial bioavailable calcium.^1,4

Plant-based diets can supply sufficient calcium through strategic food selection. However, bioavailability varies widely depending on the plant matrix and antinutrient content. Oxalic and phytic acids (oxalates and phytates) bind calcium and reduce absorption by forming insoluble complexes. For example, spinach contains high levels of calcium but also abundant oxalates, resulting in an absorption rate of only ~5%. In contrast, low-oxalate vegetables such as kale, broccoli, and bok choy allow absorption efficiencies exceeding 40%.^4,5

Other plant-derived sources with favorable calcium absorption include fortified soy, oat, and almond milks, calcium-set tofu, chia seeds, almonds, and white beans. Fortified foods such as orange juice and breakfast cereals are also widely recommended to support adequate intake, particularly in vegan diets.^1,4

Health benefits of calcium

The principal long-term benefit of sufficient calcium intake is the maintenance of bone mineral density (BMD). A 2022 meta-analysis of 43 randomized controlled trials (7,382 participants) showed that increasing calcium intake among adults under 35 years improved BMD significantly at multiple skeletal sites.⁶

Among postmenopausal women, calcium supplementation has been demonstrated to reduce bone loss over extended treatment periods, though its independent effect on fracture risk remains under debate. Recent reviews indicate that calcium’s bone-protective impact is optimized when combined with adequate vitamin D intake to enhance intestinal absorption and mineral deposition.^1,7,8,11

Recommended intake and deficiency risks

Calcium requirements vary by age, sex, and life stage. NIH guidelines recommend 1,300 mg/day for adolescents, 1,000 mg/day for most adults aged 19–50, and 1,200 mg/day for women over 50 or adults over 70 years. Pregnant and lactating women also require approximately 1,000 mg/day to support fetal skeletal development.^1,4

Chronic calcium deficiency contributes to osteopenia and osteoporosis, both characterized by reduced bone mass and increased fracture risk. Acute deficiency can produce symptoms such as paresthesia, muscle cramps, and, in severe cases, seizures.  High-risk groups include postmenopausal women, older adults, vegans, and individuals with lactose intolerance or malabsorption disorders.^1,2,4

Safety and excess intake

While dietary calcium is safe, excessive supplementation can lead to hypercalcemia, presenting with gastrointestinal discomfort, confusion, and fatigue. Chronically elevated calcium levels increase the risk of kidney stone formation, especially if supplements are taken on an empty stomach.⁹

According to a 2021 meta-analysis of 13 randomized controlled trials (n = 28,935), calcium supplementation, particularly at doses around 1,000 mg/day, was associated with a 15% higher risk of cardiovascular disease (CVD) and coronary heart disease in healthy postmenopausal women. This effect was not observed with dietary calcium, highlighting potential physiological differences between natural and supplemental sources.¹⁰

The Tolerable Upper Intake Level (UL) is 2,500 mg/day for adults 19–50 and 2,000 mg/day for those 51 and older. Individuals using supplements should monitor total intake, including dietary sources, to avoid exceeding these limits.^1,4

Conclusions

Calcium is indispensable for skeletal, dental, and neuromuscular function. Adequate intake from diverse, bioavailable food sources supports bone density and prevents deficiency-related disorders throughout life.

Optimal calcium metabolism depends on the synergistic actions of vitamin D and magnesium. Magnesium acts as a cofactor for enzymes that activate and inactivate vitamin D, while vitamin D enhances both calcium and magnesium absorption in the intestine. Balanced intake of these nutrients is therefore essential for maintaining bone strength, preventing vascular calcification, and promoting overall metabolic health.¹¹

References

1. National Institutes of Health, Office of Dietary Supplements. (11 July 2025-a). Calcium: Fact sheet for health professionals. https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/. Accessed 02 October 2025.
2. Drake, T. M., & Gupta, V. (08 January 2024). Calcium. In StatPearls [Internet]. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK557683/.
3. Shlisky, J., Mandlik, R., Askari, S., et al. (2022). Calcium deficiency worldwide: prevalence of inadequate intakes and associated health outcomes. Annals of the New York Academy of Sciences 1512(1); 10-28. DOI:10.1111/nyas.14758, https://nyaspubs.onlinelibrary.wiley.com/doi/10.1111/nyas.14758.
4. National Institutes of Health, Office of Dietary Supplements. (06 October 2022-b). Calcium: Fact sheet for consumers. https://ods.od.nih.gov/pdf/factsheets/calcium-consumer.pdf. Accessed 02 October 2025.
5. Shkembi, B., & Huppertz, T. (2021). Calcium Absorption from Food Products: Food Matrix Effects. Nutrients 14(1); 180. DOI:10.3390/nu14010180, https://www.mdpi.com/2072-6643/14/1/180.
6. Liu, Y., Le, S., Liu, Y., et al. (2022). The effect of calcium supplementation in people under 35 years old: A systematic review and meta-analysis of randomized controlled trials. eLife 11. DOI:10.7554/eLife.79002, https://elifesciences.org/articles/79002.
7. Shea, B., Wells, G., Cranney, A., et al. (2002). VII. Meta-Analysis of Calcium Supplementation for the Prevention of Postmenopausal Osteoporosis. Endocrine Reviews 23(4); 552-559. DOI:10.1210/er.2001-7002, https://academic.oup.com/edrv/article/23/4/552/2424151.
8. Bailey, R. L., Zou, P., Wallace, T. C., et al. (2019). Calcium Supplement Use Is Associated With Less Bone Mineral Density Loss, But Does Not Lessen the Risk of Bone Fracture Across the Menopause Transition: Data From the Study of Women's Health Across the Nation. JBMR Plus 4(1). DOI:10.1002/jbm4.10246, https://onlinelibrary.wiley.com/doi/10.1002/jbm4.10246.
9. Mayo Clinic. (08 March 2024). Hypercalcemia. Mayo Foundation for Medical Education and Research. https://www.mayoclinic.org/diseases-conditions/hypercalcemia/symptoms-causes/syc-20355523. Accessed 02 October 2025.
10. Myung, S., Kim, H., Lee, Y., et al. (2021). Calcium Supplements and Risk of Cardiovascular Disease: A Meta-Analysis of Clinical Trials. Nutrients 13(2); 368. DOI:10.3390/nu13020368, https://www.mdpi.com/2072-6643/13/2/368.
11. Shahsavani, Z., Asadi, A., Shamshirgardi, E., & Akbarzadeh, M. (2021). Vitamin D, Magnesium and Their Interactions: A Review. International Journal of Nutrition Sciences 6(3). DOI:10.30476/ijns.2021.91766.1144, https://ijns.sums.ac.ir/article_47789.html.

Further Reading

• All Calcium Content
• Calcium - What is Calcium?
• Calcium Compounds
• Uses of Calcium
• Calcium and Diet

Last Updated: Oct 21, 2025