Trends in Reported Calcium and Magnesium Intake from Diet and Supplements by Demographic Factors: National Health and Nutrition Examination Survey, 2003-2018.

Background: Calcium and magnesium are important micronutrients necessary for normal body functioning.

Objective: The objective of the study was to approximate usual nutrient intakes and estimate proportion of adults meeting the Estimated Average Requirement (EAR) of calcium and magnesium from diet, and diet plus supplements (total intake). Trends in the proportion of adults meeting the EAR were estimated by sex, age, and race and ethnicity.

Design: The study utilized data from the National Health and Nutrition Examination Survey, a cross-sectional survey of a nationally representative sample of the US civilian and noninstitutionalized population.

Participants And Setting: The continuous National Health and Nutrition Examination Survey survey data from 2003-2004 through 2017-2018 for dietary intake, and 2007-2008 through 2017-2018 for total intake were analyzed. The study sample included men and women (not lactating/pregnant) ages 19 years and older with 2 reliable 24-hour dietary recalls and energy intake >500 to <6,000 kcal/day (N = 35 037).

Main Outcome Measures: Mean daily intake and trends of proportion of adults meeting/exceeding the EAR for calcium and magnesium were estimated.

Statistical Analyses Performed: The National Cancer Institute's method was used to calculate daily intakes for calcium and magnesium by demographic subgroups. SAS SURVEYMEAN and SURVEYFREQ procedures were used to estimate means ± SE for continuous variables and frequencies and percentages for categorical variables, and 2-sample t test for P values. Trends were estimated with National Cancer Institute's Joinpoint trend analysis program.

Results: Mean daily dietary calcium intake and proportions of adults meeting the EAR from both diet and supplements was lowest among women (859 mg [61.9%]), adults ages 71 years and older (865 mg [60.3%]) and non-Hispanic Black individuals (782 mg [48.6%]) compared with men, younger age groups, and other races and ethnicities. Magnesium intake reported from diet was lowest in adults ages 71 years and older (276 mg), whereas total magnesium intake and proportion of meeting the EAR from both diet and supplements was lowest in women (302 mg) and men (52%), respectively, adults ages 19 to 30 years (305 mg [48.5%]), and non-Hispanic Black individuals (274 mg [35.5%]). The trends in the proportion of women and non-Hispanic White adults meeting the EAR from total calcium intake decreased significantly (P < .05) by 2.9% and 2.0%, respectively.

Conclusions: Women and adults ages 71 years and older had the lowest reported mean daily dietary calcium intake and proportion meeting the EAR for calcium from diet and supplements. Men and adults ages 19 to 30 years had the lowest proportion meeting the EAR for magnesium from diet and supplements with adults ages 19 to 30 years also having the lowest reported total magnesium intake from diet and supplements. Non-Hispanic Black individuals had the lowest proportion of meeting the EARs for calcium and magnesium from reported total intake. The trends in the proportion of women and non-Hispanic White individuals meeting the EARs for calcium through total intake decreased over time and remained stable in other subpopulations and for magnesium.