We previously developed the Korean Calcium Assessment Tool (KCAT) for assessing the intake of calcium and vitamin D in Korean women. However, based on the Korea National Health and Nutrition Examination Survey (KNHANES) VI and VII (2013–2018), major food sources for calcium and vitamin D have changed, and the National Standard Food Composition database was updated. Therefore, the present study aimed to update the KCAT and validate the Updated KCAT.
A total of 285 women aged >19 years were asked to complete questionnaires of the KCAT and the Updated KCAT.
Calcium intake did not differ significantly between the KCAT (566±245 mg/day) and the Updated KCAT (569±248 mg/day;
The present study demonstrated that the Updated KCAT was a valid tool for the rapid evaluation of calcium and vitamin D intake for Korean women.
Osteoporosis is characterized by decreased bone density with consequence increases in bone fragility and has become a serious health problem.[
Sufficient nutrition, particularly adequate intake of calcium plays an important role in prevention and treatment of osteoporosis.[
Food frequency questionnaires (FFQ), 24-hr recall, and dietary records are used for the assessment of all the nutrient intakes, but it takes a long time to complete. Simple calcium questionnaires called the Calcium CalculatorTM [
The study was conducted in accordance with the Declaration of Helsinki, and all procedures involving human participants were approved by the Institutional Review Board (IRB) of Hanyang University (HYUIRB-202103-021). Informed consent were obtained from all participants. Korean women with >19 years old were recruited and excluded if they were pregnant or breastfeeding. Participants were recruited Hanyang University, Seoul, Korea. Two hundred and eighty-5 Korean women completed both the KCAT and Updated KCAT were included in the analysis.
Participants’ information on age, height, weight was obtained through a survey. Participants were asked to complete 2 questionnaires, the KCAT and the Updated KCAT. The dietary intake of calcium and vitamin D for the past 1 year was assessed.
Based on the KNHANES VI and VII (2013–2018), food sources of calcium and vitamin D in original KCAT were modified.[
All analyses were performed using SPSS version 26.0 (SPSS Inc., Chicago, IL, USA), and
The adequacy of the sample size was determined by the G*Power version 3.1 (Heinrich Heine University, Düsseldorf, Germany).[
Calcium intake calculated from the KCAT and the Updated KCAT were not significantly different, but vitamin D intake calculated from the Updated KCAT was significantly higher than that calculated from the KCAT (
The present study showed that intakes of calcium and vitamin D assessed by the KCAT and the Updated KCAT were positively correlated and correctly classified participants into the same quartile of intake, suggesting that the Updated KCAT was a valid tool to assess the calcium intake of Korean women. In the present study, the correlation coefficient for which using continuous variables of calcium intake estimated by the KCAT and the Updated KCAT was 0.99, and κ coefficient for which using categorical variables was 0.95, almost perfect agreement. In the previous studies, the correlation coefficients obtained from calcium intake to validate questionnaires were in the range of 0.41 to 0.98.[
In the present study, correlation coefficients of vitamin D intake between the KCAT and the Updated KCAT were 0.77. This value is higher than the desirable value which is 0.5 and it suggests that the Updated KCAT could be a good tool to assess the intake of vitamin D.[
There were a few potential weaknesses in this study. First, FFQ used in these questionnaires was not a quantitative tool to analysis food consumption. To overcome this limitation, FFQ needs to include detailed questions including visual aids for estimating portion sizes. Second, the Updated KCAT might have some reporting bias since self-reported dietary intake data was used. Third, the intake of calcium and vitamin D could be affected by seasonal variation, but the Updated KCAT was not assessed during all 4 seasons. Forth, since participants of the study were only recruited from Seoul, selection bias might be existed. Fifth, the exclusion criteria of participants were different to the previous study that validated original version of KCAT.
The Updated KCAT has a few strengths. First, the Updated KCAT is the only available survey tool to assess dietary intake of calcium and vitamin D for Korean population. Second, the Updated KCAT is simple, convenient, and easy to estimate intake of calcium and vitamin D since it can be completed within 10 to 15 min. Third, the dietary intake of calcium and vitamin D can be assessed with good validity and reproducibility. In conclusion, this study suggests that the Updated KCAT can be a useful clinical tool for the rapid evaluation of calcium and vitamin D intake for Korean women. The further study is needed to validate the Updated KCAT for other population.
The authors are grateful to the participants for their involvement in this study.
This work was supported by a National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (NRF-2021R1A2B5B02002208).
JW conducted the study, performed the statistical analysis, and wrote the first draft. YJ revised the manuscript. YP designed the study, finalized the manuscript, and was responsible for the work. All authors have read and agreed to the published version of the manuscript.
The study protocol conformed to the ethical guidelines of the World Medical Association Declaration of Helsinki and was approved by the Institutional Review Board (IRB) of Hanyang University (HYUIRB-202103-021). Informed consent were obtained from all participants.
No potential conflict of interest relevant to this article was reported.
Correlation of calcium intake (A) and vitamin D intake (B) assessed by the Korean Calcium Assessment Tool (KCAT) and the Updated KCAT.
Differences against mean of calcium intake (A) and vitamin D intake (B) between the Korean Calcium Assessment Tool (KCAT) and the Updated KCAT.
List of food items newly included in the Updated KCAT
Nutrient | Food group | Food item | Serving size | KCAT | Updated KCAT |
---|---|---|---|---|---|
Calcium | Shellfish | Shrimp | 1 cup |
- | 59.2 g |
Crab | 1 crab | - | 114.0 g | ||
Fish | Pollack | 1 serving |
18.0 g | 28.8 g | |
Croaker | 1 serving | 18.0 g | 105.0 g | ||
Skate ray | 1 serving | 18.0 g | 183.0 g | ||
Vegetable | Chili pepper | 1 cup | - | 9.3 g | |
Green pumpkin | 1 cup | - | 22.2 g | ||
Chives | 1 cup | - | 22.2 g | ||
Perilla leaf | 1 cup | - | 147.7 g | ||
Sea algae | 1 cup | - | 81.4 g | ||
| |||||
Vitamin D | Meat | Duck | 1 serving | - | 36.9 μg |
Cow liver | 1 piece | - | 0.1 μg | ||
Fish | Trout | 1 serving | 5.0 μg | 6.0 μg | |
Flatfish | 1 serving | 5.0 μg | 10.8 μg | ||
Salmon | 1 serving | 5.0 μg | 19.2 μg | ||
Mackerel | 1 serving | 5.0 μg | 6.6 μg | ||
Herring | 1 serving | 5.0 μg | 13.2 μg | ||
Saury | 1 serving | 5.0 μg | 11.4 μg | ||
Cutlass fish | 1 serving | 5.0 μg | 8.4 μg | ||
Mush-rooms | Juda’s ear | 1 cup | 19.0 μg | 27.3 μg | |
Mushrooms | 1 cup | 2.0 μg | 0.9 μg |
Based on National Standard Food Composition Tables DB 9.2.
1 cup=180 mL.
1 serving=60 g.
KCAT, Korean Calcium Assessment Tool.
Characteristics of participants and intake of calcium and vitamin D assessed by the KCAT and the Updated KCAT
Total (N=285) | Range | ||
---|---|---|---|
Age (yr) | 35.28±12.71 | 19–84 | |
| |||
Weight (kg) | 56.03±7.89 | 42–85 | |
| |||
Height (cm) | 161.26±6.06 | 138–176 | |
| |||
Body mass index (kg/m2) | 21.56±2.89 | 15.43–31.60 | |
| |||
Calcium (mg/day) | 0.343 | ||
KCAT | 566.58±245.72 | 154.33–1572.10 | |
Updated KCAT | 569.12±248.85 | 160.94–1547.31 | |
| |||
Vitamin D (μg/day) | <0.001 | ||
KCAT | 7.87±5.40 | 0.93–31.50 | |
Updated KCAT | 10.14±8.46 | 0.55–67.28 |
The data is presented as mean±standard deviation.
Paired
KCAT, Korean Calcium Assessment Tool.
Joint classification of calcium intake assessed of participants according to quartile by the KCAT and the Updated KCAT
Calcium intake by KCAT (mg/day) | Calcium intake by Updated KCAT (mg/day) | Cohen’s κ coefficient | |||
---|---|---|---|---|---|
1 (≤398.84) | 2 (>398.84 to ≤529.71) | 3 (>529.71 to ≤657.17) | 4 (>657.17 to ≤1547.31) | ||
1 (≤390.46) | 0.97 | 0.03 | 0.00 | 0.00 | 0.949 |
2 (>390.46 to ≤532.25) | 0.03 | 0.96 | 0.00 | 0.00 | |
3 (>532.25 to ≤658.55) | 0.00 | 0.02 | 0.96 | 0.04 | |
4 (>658.55 to ≤1572.10) | 0.00 | 0.00 | 0.04 | 0.96 |
Cohen’s κ coefficient of 0.81–1 indicates almost perfect agreement.
KCAT, Korean Calcium Assessment Tool.
Joint classification of vitamin D intake assessed of participants according to quartile by the KCAT and the Updated KCAT
Vitamin D intake by KCAT (μg/day) | Vitamin D intake by Updated KCAT (μg/day) | Cohen’s κ coefficient | |||
---|---|---|---|---|---|
1 (≤4.86) | 2 (>4.86 to ≤7.59) | 3 (>7.59 to ≤12.90) | 4 (>12.90 to ≤67.28) | ||
1 (≤3.95) | 0.62 | 0.29 | 0.09 | 0.00 | 0.410 |
2 (>3.95 to ≤6.36) | 0.31 | 0.40 | 0.17 | 0.13 | |
3 (>6.36 to ≤9.99) | 0.06 | 0.23 | 0.46 | 0.25 | |
4 (>9.99 to ≤31.5) | 0.01 | 0.08 | 0.29 | 0.62 |
Cohen’s κ coefficient of 0.41–0.60 indicates moderate agreement.
KCAT, Korean Calcium Assessment Tool.