How to determine whether your calcium intake is excessive or insufficient

Abstract

To provide a method for simply estimating the calcium intake of a subject with higher accuracy than before and less burden on the subject.SOLUTION: A method for determining excess or deficiency of calcium intake estimates the calcium intake of a subject using a magnesium / creatinine ratio in urine collected at any time from the subject as an index. The method for determining excess or deficiency of calcium intake determines the calcium intake which is an amount of calcium ingested within a period selected from within the period of three months before urine collection starting from a day of urine collection. A system calculates the subject's calcium deficiency using the method for determining excess or deficiency of calcium intake, and provides an oral composition for supplementing the calcium deficiency.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a method for determining whether a subject's calcium intake is excessive or insufficient, using the urinary magnesium / creatinine ratio as an indicator. [Background technology]

[0002] For Japanese people, calcium remains a nutrient that is lacking in all age groups. Calcium deficiency not only weakens bones and teeth, but is also a risk factor for osteoporosis in the elderly and especially in menopausal women. There is a growing need for technology that can objectively and easily estimate one's own calcium intake or deficiency. There are two main methods for estimating a subject's calcium intake: estimating it from the subject's urine and estimating it from a food record.

[0003] As a method of estimating calcium from urine, it has been reported that although there is a correlation between the calcium concentration in 24-hour urine and the average daily calcium intake calculated from the food records for four consecutive days before urine collection, the correlation coefficient is low at 0.276 (Non-Patent Document 1). It is also known that there is no correlation between the value obtained by dividing the calcium amount in 24-hour urine by body weight and the average calcium intake calculated based on a food frequency survey (FFQg method) (correlation coefficient R = -0.1193), and there is also no correlation between the value obtained by dividing the magnesium amount in 24-hour urine by body weight and the average calcium intake calculated based on a food frequency survey (correlation coefficient R = 0.1089) (Non-Patent Document 2).

[0004] In a human intervention study targeting young women aged 18 to 33 years, it is known that there is a correlation (R=0.402, p<0.001) between the value obtained by dividing the amount of calcium in 24-hour urine by body weight and the value obtained by dividing the average daily calcium intake calculated from the food records for the past 4 days by body weight (Non-Patent Document 3). However, in women, the secretion of estrogen decreases during menopause, which increases calcium outflow from bones and the like, and changes the balance between calcium absorption and excretion, so that a study targeting only young women cannot be extrapolated to menopausal or elderly women. It is also known that the balance between calcium absorption and excretion varies depending on sex and age. A method for estimating calcium intake that can be extrapolated to men and women of a wider range of ages is desired.

[0005] Urinary component concentrations are easily affected by diet, water intake, sweating, etc., and vary greatly depending on the urine volume at the time, so a 24-hour urine collection is commonly used to estimate calcium intake. 24-hour urine collection places a large burden on the subject, so there is also a method of estimating calcium intake using random urine, which reduces the burden on the subject. When estimating calcium intake using random urine, as mentioned above, urinary component concentrations are easily affected by diet, water intake, sweating, etc., and vary greatly depending on the concentration of the urine, so it is necessary to correct the urine concentration, and as a means of this, creatinine correction is used to find the ratio with the creatinine value measured at the same time.

[0006] The "Standard Tables of Food Composition in Japan," which was investigated and published by the Ministry of Education, Culture, Sports, Science and Technology and lists the nutrients per 100g of edible portion for approximately 2,200 types of food, is commonly used as a method for estimating calcium intake from dietary records. The calculation method used in this invention was to calculate the nutrients taken by the subject by comparing the intake of each food item determined from dietary records, etc., with the "Standard Tables of Food Composition in Japan."

[0007] As mentioned above, the conventional method for estimating calcium intake is to use 24-hour urine collection, but this places a heavy burden on the subject. On the other hand, there is also a method for estimating calcium intake from a dietary record, but this also requires the subject to keep a dietary record, which places a heavy burden on the subject.

[0008] The present applicant has found that there is a high correlation between the amount of magnesium in random urine and the amount of calcium intake estimated from a dietary record before urine collection, and has completed the present invention. [Prior art documents] [Non-patent literature]

[0009] [Non-Patent Document 1] Katsumi Shibata et al., FY2008 Ministry of Health, Labour and Welfare Science Research Grant Research on the construction of evidence for revising the Dietary Reference Intakes for Japanese people - Elucidation of the balance of micronutrient and macronutrient intakes - II. Report of the principal investigator 6. Nutritional assessment using new biomarkers - Utilization of urinary minerals - [Non-Patent Document 2] Satoko Kawabe et al., Journal of Kawasaki Medical Welfare Society, Vol.16, No.2, 2006, 291-297 [Non-Patent Document 3] Yoshida M et al., Food and Nutrition Sciences, 2012, 3, 123-128 Summary of the Invention [Problem to be solved by the invention]

[0010] An object of the present invention is to provide a method for easily estimating a subject's calcium intake while reducing the burden on the subject, and for determining whether the subject's calcium intake is excessive or insufficient. [Means for solving the problem]

[0011] The means for solving the problems of the present invention are as follows. 1. A method for determining whether a subject's calcium intake is excessive or insufficient, using the magnesium / creatinine ratio in random urine samples collected from the subject as an indicator to estimate the subject's calcium intake. 2. The method for determining an excess or deficiency of calcium intake described in 1., wherein the calcium intake is the amount of calcium ingested within a period selected from the three months prior to urine collection, starting from the day of urine collection. 3. A system that uses the method for determining whether a subject's calcium intake is insufficient or excessive according to 1. or 2. to calculate the subject's calcium deficiency, and provides an oral composition for compensating for the calcium deficiency. Effect of the Invention

[0012] The method for determining calcium intake deficiency or excess of the present invention can estimate calcium intake using random urine, so that the burden on the subject is small. The subject can collect a sample at home in a simple manner using a urine collection kit or the like, and the result of the determination of calcium intake deficiency or excess can be obtained by mailing this sample. Furthermore, by calculating the amount of deficiency from the obtained result of the determination of deficiency, the subject can be provided with an oral composition to make up for the deficiency. [Brief description of the drawings]

[0013] [Figure 1] Example 1: Scatter plot of urinary Mg / Cre ratio and Ca intake at dinner the day before urine collection. [Diagram 2] Example 2, Scatter plot of urinary Mg / Cre ratio versus average Ca intake over the three days prior to urine collection. [Diagram 3] Example 3, Scatter plot of urinary Mg / Cre ratio versus average Ca intake for 30 days prior to urine collection. [Figure 4] Comparative Example 1: Scatter plot of urinary Mg concentration and Ca intake at dinner the day before urine collection. [Diagram 5] Comparative Example 2, scatter plot of urinary Mg concentration versus average Ca intake over the three days prior to urine collection. [Figure 6] Comparative Example 3, scatter plot of urinary Mg concentration versus average Ca intake for 30 days prior to urine collection. [Figure 7]Comparative Example 4: Scatter plot of urinary Ca concentration and Ca intake at dinner the day before urine collection. [Figure 8] Comparative Example 5, scatter plot of urinary Ca concentration versus average Ca intake over the three days prior to urine collection. [Figure 9] Comparative Example 6: Scatter plot of urinary Ca concentration versus average Ca intake for 30 days prior to urine collection. [Figure 10] Comparative Example 7: Scatter plot of urinary Ca / Cre ratio and Ca intake at dinner the day before urine collection. [Figure 11] Comparative Example 8, scatter plot of urinary Ca / Cre ratio versus average Ca intake over the three days prior to urine collection. [Figure 12] Comparative Example 9, scatter plot of urinary Ca / Cre ratio versus average Ca intake for 30 days prior to urine collection. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The present invention will be described in detail below. The method of the present invention for determining whether calcium intake is excessive or insufficient is characterized in that it uses the magnesium / creatinine ratio in spot urine as an index. The timing of random urine collection is not particularly limited, but it is preferable to collect the urine before the first meal of the day, and it is particularly preferable to collect the first urine immediately after waking up.

[0015] The present inventors have found that there is a correlation between the magnesium / creatinine ratio in random urine and calcium intake, and have obtained the following approximate formula. (approximate formula) Calcium intake [mg / 1000kcal] = (a) × (magnesium / creatinine ratio in random urine [mg / g]) + (b) (a) is preferably 1 to 2, and more preferably 1.1 to 1.6, and (b) is preferably 100 to 300, and more preferably 150 to 260.

[0016] Based on this approximation formula, the calcium intake of a subject can be estimated from the magnesium / creatinine ratio in the subject's random urine. In addition, based on this estimated calcium intake and the standard amount of calcium required by humans per day, calcium deficiency or excess can be determined. The standard amount of calcium required by humans per day is not particularly limited, but the value indicated by the "Dietary Reference Intakes for Japanese" provided by the Ministry of Health, Labor and Welfare can be preferably used.

[0017] The calcium intake estimated by the above approximation formula is preferably the amount of calcium taken in within a period selected from the three months before urine collection starting from the urine collection date. This period is not particularly limited as long as it is within the three months before urine collection starting from the urine collection date, and can be selected from, for example, three months before urine collection, 30 days before urine collection, seven days before urine collection, three days before urine collection, one day before urine collection, etc. In order to suppress fluctuations due to the contents of a single meal, it is preferable that the period is of a certain length, and it is preferably about 3 to 30 days before urine collection starting from the urine collection date. In addition, this calcium intake can also be the average daily calcium intake taken in the intake period.

[0018] The urine collection container used in the present invention is not particularly limited as long as it has a shape and a material that does not cause deterioration of the urinary components used in urine tests performed in hospitals, testing institutions, etc. It is preferable to add a stabilizer to the urine collection container in advance to suppress deterioration of the urinary components. Here, citric acid, oxalic acid, hydrochloric acid, tartaric acid, and ascorbic acid can be used as stabilizers for urinary components, and citric acid can be preferably used. When a fixed volume of urine is added to the urine collection container, the final concentration of the stabilizer is preferably 0.01M to 1M, more preferably 0.05 to 0.5M, from the viewpoint of stabilizing the urinary components.

[0019] The calcium deficiency of a subject can be calculated based on the calcium intake estimated from the above approximation formula and the standard amount of calcium required by humans per day. Then, an oral composition containing the amount of calcium deficiency required for each subject can be provided, and the subject can be provided with the amount of calcium required per day.

[0020] The oral composition provided by the present invention can be used as a pharmaceutical product (including quasi-drugs), a functional food such as a nutritional supplement, a nutritional functional food, a food for specified health uses, a functional food with functional claims, or a food for the sick, or a general food or food additive. In order to facilitate continuous intake, it is preferable that the composition has a form such as a tablet, a capsule, a granule, a powder, a pill, a chewable tablet, an oral disintegrating tablet, a drink, or a jelly. It may be a food processed into a rod, a plate, or a gummy candy, or may be added to a general food form. Among these, the tablet or capsule form is particularly preferable from the viewpoint of ease of intake. A preparation having such a dosage form can be prepared by a conventional method, and may be a fast-release or sustained-release preparation with controlled calcium release.

[0021] Examples of calcium to be incorporated in the oral composition of the present invention include at least one type or a combination of two or more types selected from the group consisting of calcium carbonate (including uncalcined seashell calcium, uncalcined eggshell calcium, and uncalcined reef coral calcium), calcium oxide (including calcined seashell calcium, calcined eggshell calcium, and calcined reef coral calcium), calcium hydroxide, calcium phosphate (including uncalcined bone calcium, calcined bone calcium, and calcined whey calcium), tricalcium phosphate, calcium glycerophosphate, calcium citrate, calcium acetate, calcium gluconate, calcium stearate, calcium lactate, calcium sulfate, calcium chloride, calcium hydroxide, calcium dihydrogen pyrophosphate, and calcium stearoyl lactate.

[0022] In addition to calcium, the oral composition provided by the present invention can contain supplementary ingredients to increase the bioavailability of calcium, and can also contain other nutrients such as vitamins, minerals, amino acids, sugars, polypeptides, and fish oils. EXAMPLES

[0023] The amount of calcium and calories ingested from food, as well as the concentrations of calcium (Ca), magnesium (Mg), and creatinine (Cre) in urine were measured for 117 men and women in their 30s to 60s. Hereafter, calcium will be abbreviated as Ca, magnesium as Mg, and creatinine as Cre.

[0024] (Ca intake) The subjects were asked to record the contents of each meal (food and intake amount) for 30 days. The intake amount of each food determined from the dietary records was compared with the Standard Tables of Food Composition in Japan, 2015 Edition (7th Revised Edition), to calculate the subjects' calcium and calorie intake. The Ca intake was divided by the calorie intake at dinner on the day before urine collection to obtain the Ca intake per 1000 kcal, which was designated as the Ca intake at dinner on the day before urine collection [mg / 1000 kcal]. Similarly, the average daily Ca intake for the 3 days and 30 days before urine collection was divided by the average daily calorie intake to obtain the Ca intake per 1000 kcal, which was designated as the average Ca intake for the 3 days and 30 days before urine collection [mg / 1000 kcal / day] and the average Ca intake for the 30 days before urine collection [mg / 1000 kcal / day], respectively.

[0025] (Urine collection) On the final day of the study, subjects were asked to collect two 10 mL urine samples (the first urine sample taken immediately after waking up) in the early morning. One of the two urine collection containers was used for measuring Mg, and a stabilizer (citric acid) was added to it in advance to a final concentration of 0.1M. The other of the two urine collection containers was used to measure Ca and Cre, and no stabilizer was added.

[0026] (Quantitative analysis of urinary components) Urinary Ca concentration was measured using Cikafit Ca reagent (CPZ-III chelate colorimetric method, Kyokuto Pharmaceutical Industries Co., Ltd.), urinary Mg concentration was measured using Aqua Auto Kainos Mg-II reagent (ICDH method, Kainos Corporation), and urinary Cre concentration was measured using Cika Liquid-N CRE reagent (enzymatic method, Kanto Chemical Co., Ltd.), and they were automatically analyzed using a specimen testing device (ACCUTE RX, Canon Medical Systems Corporation). From the analysis results, the urinary Ca concentration [mg / mL], Mg concentration [mg / mL], Cre concentration [g / mL], Ca / Cre ratio [mg / g], and Mg / Cre ratio [mg / g] were calculated.

[0027] (Correlation coefficient and approximate formula) The correlation coefficients and approximate equations between calcium intake (calcium intake at dinner the day before urine collection, average daily calcium intake for the three days before urine collection, and average daily calcium intake for the 30 days before urine collection) and urinary components (Ca concentration, Ca / Cre ratio, Mg concentration, and Mg / Cre ratio) were calculated. The results are shown in Table 1. [Table 1]

[0028] 〔result〕 Example 1 There was a correlation between the urinary Mg / Cre ratio and the Ca intake at the dinner on the day before urine collection, with the correlation coefficient R = 0.253, statistical value P = 0.006, and the approximate equation "Ca intake = 1.525 × urinary Mg / Cre ratio + 183.8" being obtained. Example 2 There was a high correlation between the urinary Mg / Cre ratio and the average daily Ca intake for the three days prior to urine collection, with a correlation coefficient of R = 0.389, statistical value P = 0.00001, and an approximate equation of "Ca intake = 1.507 × urinary Mg / Cre ratio + 214.4" obtained. Example 3 There was a high correlation between the urinary Mg / Cre ratio and the average daily Ca intake for the 30 days prior to urine collection, with a correlation coefficient of R = 0.343, statistical value P = 0.0002, and an approximate equation of "Ca intake = 1.166 × urinary Mg / Cre ratio + 238.3" obtained. (Comparative Examples 1 to 9) As shown in Comparative Examples 1 to 9, none of the urinary Mg concentration, urinary Ca concentration, and urinary Ca / Cre ratio showed a correlation with the Ca intake.

[0029] As shown in Examples 1 to 3, there is a high correlation between the urinary Mg / Cre ratio and Ca intake, and by using an approximation equation, the Ca intake of a subject could be estimated more accurately and simply from the subject's urinary Mg / Cre ratio than in the past.

Claims

1. A method for estimating calcium intake, which estimates the average daily calcium intake taken by a subject within a period selected from 3 to 30 days prior to urine collection, starting from the day of urine collection, using the magnesium / creatinine ratio in the subject's random urine as an index, based on the following approximate formula: (approximate formula) Average daily calcium intake [mg / 1000 kcal] = (a) × (magnesium / creatinine ratio in random urine [mg / g]) + (b) (Wherein, (a) is 1 to 2, and (b) is 100 to 300)

2. The method for estimating calcium intake according to claim 1, wherein the random urine sample is a first urine sample.

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