Hypovitaminosis D and K are highly prevalent and independent of overall malnutrition in the institutionalized elderly.

Asia Pac J Clin Nutr. 2010;19(1):49-56.

Kuwabara A, Himeno M, Tsugawa N, Kamao M, Fujii M, Kawai N, Fukuda M, Ogawa Y, Kido S, Okano T, Tanaka K.
Department of Food and Nutrition, Kyoto Women's University, 35, Imakumano-kitahiyoshicho, Higashiyama 605-8501 Japan. tanakak at kyoto-wu.ac.jp.

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 mug/day) {280 IU} exceeded the Japanese Adequate Intake (AI) of 5.0 mug/day, average serum 25OH-D concentration was in the hypovitaminosis D range (11.1 ng/mL).

Median vitamin K intake was 168 mug/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. PMID: 20199987