Feeding your bones with Calcium and Vitamin D3 does not prevent postmenopausal height loss: WHI post hoc analysis

Clinical Pearls:

1. The current recommendation by Institute of Medicine(IOM) Dietary Reference Intakes is 1200 mg of calcium (total of diet and supplement) and 800 international units of vitamin D daily for most postmenopausal women  for prevention of osteoporosis.
2. The USPSTF recommends against daily supplementation with 400 IU or less of vitamin D₃ and 1000 mg or less of calcium for the primary prevention of fractures in noninstitutionalized postmenopausal women. (D recommendation) due to lack of sufficient evidence for its benefits.
3. Post hoc analysis of Women’s Health Initiative study which included 36,282 healthy postmenopausal women who received 1,000 mg of elemental calcium as calcium carbonate with 400 IU of vitamin D3 daily (CaD) did not show any statistically significant benefits in reducing the menopausal height loss or hip/vertebral fracture risk. 

Height loss is a common phenomenon associated with aging. Vertebral fractures, changes in spinal curvatures and narrowing of the intervertebral discs are many factors that contribute to this shrinkage. Spinal deterioration combined with muscle loss causes that hunched look we all are familiar with.

A large French study published in Canadian Medical Journal observed a mean loss of nearly two inches since early adulthood in large number of postmenopausal women over the age of 60 years.[1]

On an average people, tend to lose ¼ to ½ inch every 10 years after the age of 50 years, with women losing more than men.[2] A loss of 4 cm or more in height over 10 years seems to be associated with a significant decrease of BMD, and it can be recommended as a clinical marker of osteoporosis.[3]

While it is not entirely possible to prevent the height loss as genetics and ‘how much bone you built when you were young’ plays a very important part.  Feeding your bones with Calcium and Vitamin D (CaD) has been advocated as one of the many ways to prevent osteoporosis and height loss as you age.

The clinical research data and studies show conflicting results when it comes to daily recommendation of CaD for prevention of osteoporosis and fracture risk in postmenopausal women.

The current recommendation by Institute of Medicine(IOM) Dietary Reference Intakes  is 1200 mg of calcium (total of diet and supplement) and 800 international units of vitamin D daily for most postmenopausal women with for prevention of osteoporosis.[4]

In contrast, the U.S. Preventive Services Task Force (USPSTF) recommendation statement on vitamin D and calcium supplementation to prevent fractures in adults were recently published in Annals of Internal Medicine.[5] The USPSTF recommends against daily supplementation with 400 IU or less of vitamin D₃ and 1000 mg or less of calcium for the primary prevention of fractures in noninstitutionalized postmenopausal women. (D recommendation) due to lack of sufficient evidence for its benefits.[6]

The Women's Health Initiative (WHI) CaD trial of 36,282 healthy postmenopausal women with supplementation of 1,000 mg of elemental calcium as calcium carbonate with 400 IU of vitamin D3 daily (CaD) resulted in a small but significant improvement in hip bone density, did not significantly reduce hip fracture.[7] The researchers recommended further trials with larger doses.

Post hoc analysis of the data from the same WHI CaD double blind randomized trial in postmenopausal women at 40 US clinical centers were conducted for prevention of height loss. The study was published in December edition of Menopause journal.[8]

Height was measured every year in 36,282 women with a stadiometer for an average of 6 years. The women were than randomized to receive CaD supplementation or placebo. The average height loss was 1.28 mm/y for women receiving CaD versus 1.26 mm/y for women getting a placebo (P = 0.35).

So, CaD supplementation does not prevent the height loss in postmenopausal women.

So, CaD supplementation does not prevent the height loss or fracture risk in postmenopausal women. The USPSTF stats “Research is needed to determine whether daily supplementation with greater than 400 IU of vitamin D₃ and greater than 1,000 mg of calcium reduces fracture incidence in postmenopausal women or older men”.

Estrogen with or without a progestin as a Hormone Replacement Therapy was effective at preventing bone loss, reducing risk for hip, clinical vertebral and total fractures.

But, it is not solely advocated to promote skeletal health.

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[1] https://www.sciencedaily.com/releases/2010/03/100322121107.htm

[2] http://www.berkeleywellness.com/self-care/preventive-care/article/why-you-shrink-you-age

[3] https://www.ncbi.nlm.nih.gov/pubmed/8088069

[4] Institute of Medicine. Dietary Reference Intakes for Calcium and Vitamin D. Washington, DC: National Academies Press; 2011

[5] http://annals.org/aim/article/1655858/vitamin-d-calcium-supplementation-prevent-fractures-adults-u-s-preventive

[6] https://www.uspreventiveservicestaskforce.org/Page/Document/UpdateSummaryFinal/vitamin-d-and-calcium-to-prevent-fractures-preventive-medication

[7] http://www.nejm.org/doi/full/10.1056/NEJMoa055218

[8] http://journals.lww.com/menopausejournal/Citation/2016/12000/Calcium_plus_vitamin_D_supplementation_and_height.5.aspx