If you grew up like me, you had milk several times each day: on your cereal at breakfast and in a glass with lunch and dinner. Your parents told you that milk is good for your bones and that you need the vitamins to grow. Advertisements cemented this association in your mind: to have strong bones, you must drink milk.
Strong bones are important to prevent osteoporosis, which usually occurs later in life and is caused by dramatic bone mineral loss. When bones have low bone mineral density (BMD), they are exceptionally weak and prone to fracture. While anyone can develop osteoporosis, it most commonly affects white and Asian, post-menopausal women and people who smoke or take certain medications.1Osteoporosis – Symptoms and causes – Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/osteoporosis/symptoms-causes/syc-20351968
How is drinking milk supposed to help my bones?
We tend to think of bones as static scaffolding for our bodies, but bones actually change all the time: Minerals are taken out of bones and put back in; bone tissue is broken down and new tissue formed. From childhood to your early to mid-30s, your bones are growing and accumulating minerals until you reach your peak BMD. After this point, you slowly lose bone minerals and bone tissue as you age. When women hit menopause, the decrease becomes more rapid, which is why osteoporosis is most common in women. If you lose too much mineral density, you develop osteoporosis.
If you achieve a high BMD in your 30s, you can avoid developing osteoporosis later in life because your BMD stays above the diagnostic threshold. Therefore, BMD plays a major role in determining your risk of developing osteoporosis. By providing calcium, milk is supposed to help you achieve and maintain a healthy BMD.
So, will my peak bone mineral density be higher if I drink milk?
Bones develop the most during childhood, so many studies have looked at the effect of drinking milk on children’s bones. Studies on hundreds of boys and girls show that children who drink milk daily achieve a greater BMD than those who don’t.2Bonjour JP, Carrie AL, Ferrari S, et al. Calcium-enriched foods and bone mass growth in prepubertal girls: a randomized, double-blind, placebo-controlled trial. J. Clin. Invest. 1997;99(6):1287-1294. doi:10.1172/JCI119287. https://www.ncbi.nlm.nih.gov/pubmed/90775383Chevalley T, Bonjour JP, Ferrari S, Hans D, Rizzoli R. Skeletal site selectivity in the effects of calcium supplementation on areal bone mineral density gain: a randomized, double-blind, placebo-controlled trial in prepubertal boys. J. Clin. Endocrinol. Metab. 2005;90(6):3342-3349. doi:10.1210/jc.2004-1455. https://www.ncbi.nlm.nih.gov/pubmed/157558664Arab Ameri E, Dehkhoda MR, Hemayattalab R. Bone mineral density changes after physical training and calcium intake in students with attention deficit and hyper activity disorders. Res. Dev. Disabil. 2012;33(2):594-599. doi:10.1016/j.ridd.2011.10.017. https://www.ncbi.nlm.nih.gov/pubmed/221555325Reza SM, Rasool H, Mansour S, Abdollah H. Effects of calcium and training on the development of bone density in children with Down syndrome. Res. Dev. Disabil. 2013;34(12):4304-4309. doi:10.1016/j.ridd.2013.08.037. https://www.ncbi.nlm.nih.gov/pubmed/24157403 Several years after these studies ended, researchers re-measured the children’s BMD and found that the children who drank milk during the studies still had greater BMDs than the children who didn’t, suggesting that high calcium intake in early childhood has a lasting effect and can positively affect bone density into adulthood.3Chevalley T, Bonjour JP, Ferrari S, Hans D, Rizzoli R. Skeletal site selectivity in the effects of calcium supplementation on areal bone mineral density gain: a randomized, double-blind, placebo-controlled trial in prepubertal boys. J. Clin. Endocrinol. Metab. 2005;90(6):3342-3349. doi:10.1210/jc.2004-1455. https://www.ncbi.nlm.nih.gov/pubmed/157558666Bonjour JP, Chevalley T, Ammann P, Slosman D, Rizzoli R. Gain in bone mineral mass in prepubertal girls 3.5 years after discontinuation of calcium supplementation: a follow-up study. Lancet 2001;358(9289):1208-1212. doi:10.1016/S0140-6736(01)06342-5. https://www.ncbi.nlm.nih.gov/pubmed/11675056
This is also supported by retrospective studies. Two studies, one surveying over 4,000 adult women and one surveying over 500 women, showed that drinking milk in youth is significantly associated with a higher BMD in adulthood.7Opotowsky AR, Bilezikian JP. Racial differences in the effect of early milk consumption on peak and postmenopausal bone mineral density. J. Bone Miner. Res. 2003;18(11):1978-1988. doi:10.1359/jbmr.2003.18.11.1978. https://www.ncbi.nlm.nih.gov/pubmed/146065108Soroko S, Holbrook TL, Edelstein S, Barrett-Connor E. Lifetime milk consumption and bone mineral density in older women. Am. J. Public Health 1994;84(8):1319-1322. https://www.ncbi.nlm.nih.gov/pubmed/8059895
In other association studies, scientists observed that children who avoid drinking milk have lower BMDs, shorter heights, and lower bone health than those that drink milk regularly.9Black RE, Williams SM, Jones IE, Goulding A. Children who avoid drinking cow milk have low dietary calcium intakes and poor bone health. Am. J. Clin. Nutr. 2002;76(3):675-680. doi:10.1093/ajcn/76.3.675. https://www.ncbi.nlm.nih.gov/pubmed/1219801710Henderson RC, Hayes PR. Bone mineralization in children and adolescents with a milk allergy. Bone Miner. 1994;27(1):1-12. https://www.ncbi.nlm.nih.gov/pubmed/784954111Infante D, Tormo R. Risk of inadequate bone mineralization in diseases involving long-term suppression of dairy products. J. Pediatr. Gastroenterol. Nutr. 2000;30(3):310-313. https://www.ncbi.nlm.nih.gov/pubmed/10749417 Overall, scientific research shows that drinking milk as a child correlates with higher BMD, both as a child and as an adult.
I’m glad that I drank milk as a child, but now I’m an adult and I’m already past my mid-30s. Will drinking milk do anything for my bones now?
Your bones are not storing calcium like they did when you were younger, but they can still benefit from milk. Research on hundreds of postmenopausal women shows that women who drink milk experience less BMD loss than women who don’t.12Prince R, Devine A, Dick I, et al. The effects of calcium supplementation (milk powder or tablets) and exercise on bone density in postmenopausal women. J. Bone Miner. Res. 1995;10(7):1068-1075. doi:10.1002/jbmr.5650100711. https://www.ncbi.nlm.nih.gov/pubmed/748428213Kruger MC, Ha PC, Todd JM, et al. High-calcium, vitamin D fortified milk is effective in improving bone turnover markers and vitamin D status in healthy postmenopausal Chinese women. Eur. J. Clin. Nutr. 2012;66(7):856-861. doi:10.1038/ejcn.2012.54. https://www.ncbi.nlm.nih.gov/pubmed/2264434814Gui JC, Brašić JR, Liu XD, et al. Bone mineral density in postmenopausal Chinese women treated with calcium fortification in soymilk and cow’s milk. Osteoporos. Int. 2012;23(5):1563-1570. doi:10.1007/s00198-012-1895-z. https://www.ncbi.nlm.nih.gov/pubmed/2228230015Chee WSS, Suriah AR, Chan SP, Zaitun Y, Chan YM. The effect of milk supplementation on bone mineral density in postmenopausal Chinese women in Malaysia. Osteoporos. Int. 2003;14(10):828-834. doi:10.1007/s00198-003-1448-6. https://www.ncbi.nlm.nih.gov/pubmed/1291595916Bonjour J-P, Brandolini-Bunlon M, Boirie Y, et al. Inhibition of bone turnover by milk intake in postmenopausal women. Br. J. Nutr. 2008;100(4):866-874. doi:10.1017/S0007114508937429. https://www.ncbi.nlm.nih.gov/pubmed/18298870 This means that drinking milk can slow mineral loss as you age. This could push back the onset of osteoporosis by years, decades, or prevent it altogether.
Middle-aged men and pre-menopausal women can also benefit in the long run from drinking milk. One study questioned over 4,000 men and women and found that those who drank one or more glasses of milk per day during midlife had greater BMDs at old age than people who drank less than one glass per week.17Eysteinsdottir T, Halldorsson TI, Thorsdottir I, et al. Milk consumption throughout life and bone mineral content and density in elderly men and women. Osteoporos. Int. 2014;25(2):663-672. doi:10.1007/s00198-013-2476-5. https://www.ncbi.nlm.nih.gov/pubmed/23948877 It seems that no matter what age you are, drinking milk can benefit your bones.
What if I don’t like to drink milk? Am I doomed or can I drink soy milk instead? Or take calcium supplement pills?
You are certainly not doomed! Milk is an excellent source of calcium as well as vitamin D and protein, which also benefit your bones. However, there are many other calcium sources:
- Other dairy products. Cheese, yogurt, and even ice cream can benefit bones due to their similar nutrient profile to milk.18Bonjour J-P, Benoit V, Rousseau B, Souberbielle J-C. Consumption of vitamin D-and calcium-fortified soft white cheese lowers the biochemical marker of bone resorption TRAP 5b in postmenopausal women at moderate risk of osteoporosis fracture. J. Nutr. 2012;142(4):698-703. doi:10.3945/jn.111.153692. https://www.ncbi.nlm.nih.gov/pubmed/2235773919Chan GM, Hoffman K, McMurry M. Effects of dairy products on bone and body composition in pubertal girls. J. Pediatr. 1995;126(4):551-556. https://www.ncbi.nlm.nih.gov/pubmed/769953220AlQuaiz AM, Kazi A, Tayel S, et al. Prevalence and factors associated with low bone mineral density in Saudi women: a community based survey. BMC Musculoskelet. Disord. 2014;15:5. doi:10.1186/1471-2474-15-5. 19-23. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3893466/21van der Hee RM, Miret S, Slettenaar M, et al. Calcium absorption from fortified ice cream formulations compared with calcium absorption from milk. J. Am. Diet. Assoc. 2009;109(5):830-835. doi:10.1016/j.jada.2009.02.017. https://www.ncbi.nlm.nih.gov/pubmed/1939446922Bonjour J-P, Benoit V, Payen F, Kraenzlin M. Consumption of yogurts fortified in vitamin D and calcium reduces serum parathyroid hormone and markers of bone resorption: a double-blind randomized controlled trial in institutionalized elderly women. J. Clin. Endocrinol. Metab. 2013;98(7):2915-2921. doi:10.1210/jc.2013-1274. https://www.ncbi.nlm.nih.gov/pubmed/23653431
- Soy milk. Some studies show that soy milk and cow milk have similar effects on BMD23Ho SC, Guldan GS, Woo J, et al. A prospective study of the effects of 1-year calcium-fortified soy milk supplementation on dietary calcium intake and bone health in Chinese adolescent girls aged 14 to 16. Osteoporos. Int. 2005;16(12):1907-1916. doi:10.1007/s00198-005-1963-8.24-25 https://www.ncbi.nlm.nih.gov/pubmed/1613364624Lydeking-Olsen E, Beck-Jensen J-E, Setchell KDR, Holm-Jensen T. Soymilk or progesterone for prevention of bone loss–a 2 year randomized, placebo-controlled trial. Eur. J. Nutr. 2004;43(4):246-257. doi:10.1007/s00394-004-0497-8. https://link.springer.com/article/10.1007/s00394-004-0497-8, but other studies do not.15Kruger MC, Ha PC, Todd JM, et al. High-calcium, vitamin D fortified milk is effective in improving bone turnover markers and vitamin D status in healthy postmenopausal Chinese women. Eur. J. Clin. Nutr. 2012;66(7):856-861. doi:10.1038/ejcn.2012.54. https://www.ncbi.nlm.nih.gov/pubmed/22644348 The varied findings may result from different soy milks used in the studies.
- Calcium supplement pills. Usually made from calcium carbonate or calcium citrate, these are shown to have favorable effects on BMD and bone mineral content.25Dibba B, Prentice A, Ceesay M, Stirling DM, Cole TJ, Poskitt EM. Effect of calcium supplementation on bone mineral accretion in gambian children accustomed to a low-calcium diet. Am. J. Clin. Nutr. 2000;71(2):544-549. doi:10.1093/ajcn/71.2.544. https://www.ncbi.nlm.nih.gov/pubmed/1064827026Lee WT, Leung SS, Wang SH, et al. Double-blind, controlled calcium supplementation and bone mineral accretion in children accustomed to a low-calcium diet. Am. J. Clin. Nutr. 1994;60(5):744-750. doi:10.1093/ajcn/60.5.744. https://www.ncbi.nlm.nih.gov/pubmed/761910527Lee WT, Leung SS, Leung DM, Tsang HS, Lau J, Cheng JC. A randomized double-blind controlled calcium supplementation trial, and bone and height acquisition in children. Br. J. Nutr. 1995;74(1):125-139. https://www.ncbi.nlm.nih.gov/pubmed/754782328Prentice A, Ginty F, Stear SJ, Jones SC, Laskey MA, Cole TJ. Calcium supplementation increases stature and bone mineral mass of 16- to 18-year-old boys. J. Clin. Endocrinol. Metab. 2005;90(6):3153-3161. doi:10.1210/jc.2004-2114. https://www.ncbi.nlm.nih.gov/pubmed/1575585629Stear SJ, Prentice A, Jones SC, Cole TJ. Effect of a calcium and exercise intervention on the bone mineral status of 16-18-y-old adolescent girls. Am. J. Clin. Nutr. 2003;77(4):985-992. doi:10.1093/ajcn/77.4.985. https://www.ncbi.nlm.nih.gov/pubmed/1266330130Jackson RD, LaCroix AZ, Gass M, et al. Calcium plus vitamin D supplementation and the risk of fractures. N. Engl. J. Med. 2006;354(7):669-683. doi:10.1056/NEJMoa055218. https://www.ncbi.nlm.nih.gov/pubmed/1648163531Ruml LA, Sakhaee K, Peterson R, Adams-Huet B, Pak CY. The effect of calcium citrate on bone density in the early and mid-postmenopausal period: a randomized placebo-controlled study. Am. J. Ther. 1999;6(6):303-311. https://www.ncbi.nlm.nih.gov/pubmed/11329114 It is not known if these supplements provide a lasting benefit if you stop taking them, as observed for dairy products.32Umaretiya PJ, Thacher TD, Fischer PR, Cha SS, Pettifor JM. Bone mineral density in Nigerian children after discontinuation of calcium supplementation. Bone 2013;55(1):64-68. doi:10.1016/j.bone.2013.03.017. http://europepmc.org/abstract/med/23567161
- Vegetables and fish. Some vegetables and fish contain a lot of calcium and eating enough of these can help you reach your daily intake recommendation and benefit your BMD.32Umaretiya PJ, Thacher TD, Fischer PR, Cha SS, Pettifor JM. Bone mineral density in Nigerian children after discontinuation of calcium supplementation. Bone 2013;55(1):64-68. doi:10.1016/j.bone.2013.03.017. http://europepmc.org/abstract/med/2356716133Park H-M, Heo J, Park Y. Calcium from plant sources is beneficial to lowering the risk of osteoporosis in postmenopausal Korean women. Nutr. Res. 2011;31(1):27-32. doi:10.1016/j.nutres.2010.12.005. https://www.ncbi.nlm.nih.gov/pubmed/21310303 You have to make sure you eat enough of vegetables though—most people don’t!
Great, I have options! How much calcium do I need each day?
According to the Institute of Medicine34Calcium and Vitamin D: Top Foods to Prevent Osteoporosis. https://www.webmd.com/food-recipes/guide/calcium-vitamin-d-foods:
You can check your current daily calcium intake using this helpful calculator:
They say that too much of a good thing is a bad thing and this applies to calcium. Consuming more than 2,000mg per day may put you at risk for kidney stones, particularly if you are over 50 years old.1Osteoporosis – Symptoms and causes – Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/osteoporosis/symptoms-causes/syc-20351968
I see how watching my diet can help my bones. Is there anything else I can do?
Absolutely! Exercise may be just as important as calcium in building strong bones. Many studies have looked at exercise’s effect on BMD and found that exercise significantly benefits bones, especially when combined with high calcium intake.4Arab Ameri E, Dehkhoda MR, Hemayattalab R. Bone mineral density changes after physical training and calcium intake in students with attention deficit and hyper activity disorders. Res. Dev. Disabil. 2012;33(2):594-599. doi:10.1016/j.ridd.2011.10.017. https://www.ncbi.nlm.nih.gov/pubmed/221555325Reza SM, Rasool H, Mansour S, Abdollah H. Effects of calcium and training on the development of bone density in children with Down syndrome. Res. Dev. Disabil. 2013;34(12):4304-4309. doi:10.1016/j.ridd.2013.08.037. https://www.ncbi.nlm.nih.gov/pubmed/2415740312Prince R, Devine A, Dick I, et al. The effects of calcium supplementation (milk powder or tablets) and exercise on bone density in postmenopausal women. J. Bone Miner. Res. 1995;10(7):1068-1075. doi:10.1002/jbmr.5650100711. https://www.ncbi.nlm.nih.gov/pubmed/748428231Stear SJ, Prentice A, Jones SC, Cole TJ. Effect of a calcium and exercise intervention on the bone mineral status of 16-18-y-old adolescent girls. Am. J. Clin. Nutr. 2003;77(4):985-992. doi:10.1093/ajcn/77.4.985. https://www.ncbi.nlm.nih.gov/pubmed/12663301 Weight-bearing exercise, which you do anytime you fight gravity, is key for improving BMD. This includes walking, running, weight-lifting, and yoga. Exercises such as swimming and cycling are great for cardiovascular health, but have no effect on BMD.
To drink milk or not to drink milk? As long as you have a full and balanced diet, the choice is up to you!