Hypovitaminosis D and K are highly prevalent and independent of overall malnutrition in the institutionalized elderly.
There have been methodological problems for studying hypovitaminosis D and K in the elderly. First, studies were done either by evaluating food intake or measuring their circulating levels, but rarely by both in Japan. In this paper, vitamin D and K intakes and their circulating levels were simultaneously determined. Second issue is whether hypovitaminosis D and K are independent of general malnutrition, prevalent in the elderly. We tried to statistically discriminate them by principal component analysis (PCA). Fifty institutionalized elderly were evaluated for their circulating 25 hydroxy-vitamin D (25OH-D), intact parathyroid hormone (PTH), phylloquinone (PK), menaquinone-7 (MK-7) levels, and their food intake. Although average vitamin D intake (7.0 microg/day) exceeded the Japanese Adequate Intake (AI) of 5.0 microg/day, average serum 25OH-D concentration was in the hypovitaminosis D range (11.1 ng/mL). Median vitamin K intake was 168 microg/day, approximately 2.5 times as high as AI for vitamin K. Nevertheless, plasma PK and MK-7 concentrations were far lower than those of healthy Japanese elderly over 70 years old. PCA yielded four components; each representing overall nutritional, vitamin K2, vitamin D, and vitamin K1 status, respectively. Since these components are independent of each other, vitamin D- and K-deficiency in these subjects could not be explained by overall malnutrition alone. In summary, institutionalized elderly had a high prevalence of hypovitaminosis D and K, and the simultaneous determination of their circulating level and dietary intake is mandatory in such studies. PCA would yield fruitful results for eliminating the interference by confounders in a cross-sectional study.
Kuwabara
Akiko
A
Department of Food and Nutrition, Kyoto Women's University, 35, Imakumano-kitahiyoshicho, Higashiyama 605-8501 Japan.
Himeno
Masako
M
Tsugawa
Naoko
N
Kamao
Maya
M
Fujii
Minori
M
Kawai
Nobuko
N
Fukuda
Miyuki
M
Ogawa
Yoko
Y
Kido
Shoko
S
Okano
Toshio
T
Tanaka
Kiyoshi
K
D015652:25-Hydroxyvitamin D 2 / Q000097:blood; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D002112:Calcifediol / Q000097:blood; D004032:Diet; D005260:Female; D006801:Humans; D007326:Institutionalization / Q000706:statistics & numerical data*; D007564:Japan / Q000453:epidemiology; D008297:Male; D044342:Malnutrition / Q000097:blood / Q000453:epidemiology*; D009752:Nutritional Status; D010281:Parathyroid Hormone / Q000097:blood; D025341:Principal Component Analysis; D012727:Sex Characteristics; D014808:Vitamin D Deficiency / Q000097:blood* / Q000453:epidemiology*; D010837:Vitamin K 1 / Q000097:blood; D024482:Vitamin K 2 / Q000031:analogs & derivatives / Q000097:blood; D014813:Vitamin K Deficiency / Q000097:blood* / Q000453:epidemiology*
D015415:Biomarkers; D010281:Parathyroid Hormone; D024482:Vitamin K 2; D015652:25-Hydroxyvitamin D 2; D010837:Vitamin K 1; C062629:menaquinone 7; D002112:Calcifediol