Serum 25-Hydroxyvitamin D and 1, 25-Dihydroxyvitamin D Status in Relation to Nutrient Intake in Healthy Japanese Population

• Published in: Eiyōgaku zasshi Vol. 55; no. 6; pp. 305 - 313
• Main Authors: Nakamura, Mieko, Aoki, Nobuo, Fukino, Yoko, Iitoi, Yoji, Akabane, Masayuki
• Format: Journal Article
• Language: English
• Published: The Japanese Society of Nutrition and Dietetics 1997
• Subjects: 1, 25-dihydroxyvitamin D; 25-hydroxyvitamin D; ultrasonic measurement; vitamin D intake
• ISSN: 0021-5147; 1883-7921
• DOI: 10.5264/eiyogakuzashi.55.305

We conducted a collaborative study as a part of Shizuoka Prefecture Health Project (Kenmin Kenko Kiso Chousa) in November, 1995. Subjects were 99 men and 162 women aged 20 to 59 randomly selected from participants of the nutritional survey of the Project. The purpose of this study is to clarify the distribution and level of serum 25-hydroxyvitamin D and 1, 25-dihydroxyvitamin D, and the relation between dietary nutrient intake and serum vitamin D status. The results are summarized as follows. 1) The serum level of 25 (OH) D in men was higher than that in women. The average 25 (OH) D in men in their 20s was 50% higher than in women of the same age group, and 20 to 30% higher in those who were in their 30s, 40s and 50s. 2) In multiple linear regression analysis, the serum concentration of 25 (OH) D as a dependent variable was regressed by sex, age, body mass index, nutrient intake and exercise outdoors as independent variables. The concentration of 25 (OH) D was higher in men and positively related to aging and dietary vitamin D intake. 3) Two-thirds of dietary vitamin D intake was from fish and shellfish, the major source of dietary vitamin D in Japan. 4) None had serum 25 (OH) D deficiency (<10ng/ml) and 2.0% of men and 6.2% of women showed relatively low concentrations of 25 (OH) D (<15ng/ml). Average dietary vitamin D intake in the low 25 (OH) D group was significantly lower than that in the normal group at 118 and 334 IU per day respectively. The ultrasonic measurement of os calcis revealed that the mean of SOS (speed of sound) of the low 25 (OH) D (n=8) was lower than that of the normal 25 (OH) D group (n=52) at 1, 548.4 and 1, 557.1 m/sec respectively but not with statistical significance.