HTN: Calcium 2008
Click here to see the explanation of recommendation ratings (Strong, Fair, Weak, Consensus, Insufficient Evidence) and labels (Imperative or Conditional). To see more detail on the evidence from which the following recommendations were drawn, use the hyperlinks in the Supporting Evidence Section below.
If calcium is proposed as a therapy to reduce blood pressure, advise that the effect of calcium as a single nutrient on blood pressure in healthy or hypertensive adults is unclear. Epidemiological studies report that dietary patterns containing calcium lower than recommended levels (DRI) may be associated with elevated blood pressure. The effect of dietary patterns with calcium intake above the DRI on blood pressure in healthy or hypertensive adults is minimal.
Risks/Harms of Implementing This Recommendation
Conditions of Application
This recommendation applies to individuals asking about calcium as a therapy to reduce blood pressure.
Potential Costs Associated with Application
- Seven cross-sectional studies with calcium intakes below recommended levels report an association with increased blood pressure, however, it is unclear if this is confounded by other dietary factors (Jorde and Bonaa, 2000; Morikawa et al, 2002; Schroder et al, 2002; Hajjar and Kotchen, 2003; Hajjar et al, 2003; Kwok et al, 2003; Zhao et al, 2004).
- However, one cohort study did not report significant differences between hypertensive and normotensive subjects, although both groups reported low calcium intakes (Lancaster et al, 2004).
- One cross-sectional study with calcium intakes near recommended levels reported no statistically significant differences in blood pressure between hypertensive patients and controls (Silaste et al, 2000).
- One meta-analysis of calcium intakes above recommended levels showed a minimal decrease in blood pressure (Geleijnse et al, 2004).
Recommendation Strength Rationale
- Conclusion Statement is a Grade II.
- Risks/Harms of Implementing This Recommendation
The recommendations were created from the evidence analysis on the following questions. To see detail of the evidence analysis, click the blue hyperlinks below (recommendations rated consensus will not have supporting evidence linked).
What is the relationship between calcium intake and blood pressure in healthy and hypertensive adults?
Geleijnse JM, Kok FJ, Grobbee DE. Impact of dietary and lifestyle factors on the prevalence of hypertension in Western populations. Eur J Public Health. 2004; 14 (3): 235-239.
Hajjar I, Kotchen T. Regional variations of blood pressure in the United States are associated with regional variations in dietary intakes: The NHANES III Data. J Nutr. 2003; 133: 211-214.
Hajjar IM, Grim CE, Kotchen TA. Dietary calcium lowers the age-related rise in blood pressure in the United States: the NHANES III Survey. J Clin Hypertens. 2003; 5 (2): 122-126.
Jorde R, Bonaa KH. Calcium from dairy products, vitamin D intake and blood pressure: the Tromso study. Am J Clin Nutr. 2000; 71 (6): 1,530-1,535.
Kwok TCY, Chan TYK, Woo J. Relationship of urinary sodium/potassium excretion and calcium intake to blood pressure and prevalence of hypertension among older Chinese vegetarians. European Journal of Clinical Nutrition, 2003; 57: 299-304.
Lancaster KJ, Smiciklas-Wright H, Weltzel LB, Mitchell DC, Friedman JM, Jensen GL. Hypertension-related dietary patterns of rural older adults. Preventive Medicine, 2004; 38: 812-818.
Morikawa Y, Nakagawa H, Okayama A, Mikawa K, Sakata K, Miura K, Ishizaki M, Yoshita K, Naruse Y, Kagamimori S, Hashimoto T, Ueshima H. A cross-sectional study on association of calcium intake with blood pressure in Japanese population. Journal of Human Hypertension, 2002; 16 (2): 105-110.
Schroder H, Schmelz E, Marrugat J. Relationship between diet and blood pressure in a representative Mediterranean population. Eur J Nutr. 2002; 41 (4): 161-167.
Silaste M-L, Junes R, Rantala AO, Kauma H, Lilja M, Savolainen MJ, Reunanen A, Kesaniemi YA. Dietary and other non-pharmacological treatments in patients with drug-treated hypertension and control subjects. Journal of Internal Medicine. 2000; 247: 318-324.
Zhao L, Stamler J, Yan LL, Zhou B, Wu Y, Liu K, Daviglus ML, Dennis BH, Elliott P, Ueshima H, Yang J, Zhu L, Guo D, for the INTERMAP Research Group. Blood pressure differences between northern and southern Chinese: role of dietary factors. The international study on macronutrients and blood pressure. Hypertension, 2004; 43 (6): 1,332-1,337.
References not graded in Academy of Nutrition and Dietetics Evidence Analysis Process
The Dietary Reference Intakes (DRI) and Recommended Dietary Allowances (RDA) are issued by the Food and Nutrition Board of the Institute of Medicine, National Academy of Sciences.