Vitamin D deficiency as the risk of respiratory tract infections in the institutionalized elderly: A prospective 1-year cohort study.

BACKGROUND & AIMS: Respiratory tract infections (RTIs) are one of the major causes of morbidity and mortality in the elderly. Since vitamin D is known to play important roles in immunity, and its deficiency has been reported to be prevalent in the elderly, we have studied the relationship between serum 25-hydroxyvitamin D [25(OH)D] level, which is the most reliable marker for vitamin D status, and the incidence of RTIs in the institutionalized elderly by a prospective observational study. METHODS: From 208 Japanese subjects aged 60 and older fulfilling the inclusion criteria, 148 subjects remained after propensity score matching. Data were obtained from the medical records including their age, gender, histories of co-morbidities and medications, the incidence of acute RTIs including pneumonia. Measurement of serum 25(OH)D level and assessment of nutrients intake including vitamin D were done at baseline. Cox's proportional hazard analysis was performed to assess the significant predictors for RTIs during the follow-up period. RESULTS: The median observation duration was 354.2 days, and the incidence of RTIs was 75.8 person-years. Subjects with RTIs had significantly lower serum 25(OH)D concentration, and a higher prevalence of vitamin D deficiency (25(OH)D < 10 ng/mL). Cox's proportional hazard analysis revealed that vitamin D deficiency was a significant predictor for RTIs. CONCLUSIONS: Our results suggested that vitamin D deficiency was a significant predictor for an increased incidence of RTIs in institutionalized elderly, and the necessity of vitamin D supplementation for the prevention of RTIs was considered.

Nutritional Therapy with Vitamin K1 Is Effective in the Improvement of Vitamin K Status and Bone Turnover Markers in Patients with Severe Motor and Intellectual Disabilities.

We have previously reported that patients with severe motor and intellectual disabilities (SMID) have a high prevalence of vitamin K deficiency both in the liver and bone. Thus, vitamin K therapy for SMID patients should be considered. In the present study, we have studied the efficacy of nutritional therapy with vitamin K1 for improving their vitamin K status and bone metabolism markers in patients with SMID. During the 3-mo period, 19 patients under enteral feeding received vitamin K1 treatment, the dose of which was determined to meet each subject's energy requirement. Biomarkers of vitamin K insufficiency; protein induced by vitamin K absence or antagonist-II (PIVKA-II), undercarboxylated osteocalcin (ucOC), intact osteocalcin (intact OC) and bone turnover markers (tartrate-resistant acid phosphatase-5b: TRACP-5b and bone alkaline phosphatase: BAP) were measured at baseline and post treatment. The ucOC/OC ratio was calculated as a more sensitive index than ucOC for vitamin K status in the bone. After treatment, the median vitamin K intake increased from 66 to 183 µg/d, and serum levels of PIVKA-II and ucOC/OC ratio were significantly decreased. Decrements of serum ucOC level and ucOC/OC ratio were significantly associated with vitamin K intake, indicating that both markers well reflect the dose-dependent vitamin K effects. Serum levels of BAP and TRACP-5b were significantly increased after vitamin K1 therapy. Nutritional therapy with vitamin K1 effectively improved the markers for vitamin K status and bone turnover, and was considered to be a good candidate for treatment in SMID patients.

[Bone and Nutrition. The association of vitamin K intake and bone health].

The association of vitamin K with bone mineral density has been reported in some previous cohort studies and intervention studies. In cohort studies, higher vitamin K1 intake was associated with lower fracture incidence. Some intervention studies have described that vitamin K1 and vitamin K2 (menaquinone-4 : MK-4) supplementation were modestly efficacious in preventing fracture, but not in preserving bone mass. Although dietary reference intake (adequate intake : AI) for vitamin K was increased from previous value, current AI was determined as the dose sufficient to maintain normal blood coagulation with little mentioning to bone. Vitamin K intake greater than the current AI would be required for the bone health.

The association between vitamin E intake and hypertension: results from the re-analysis of the National Health and Nutrition Survey.

Recently, there has been an increasing concern about noncommunicable diseases (NCDs), in which oxidative damage plays a role. In this paper, we have re-analyzed the data from the National Health and Nutrition Survey (NHNS) 2007 to study the relationship between an NCD (e.g. hypertension) and the dietary intake of vitamin E, a potent anti-oxidative vitamin. The inclusion criteria were those aged 40 and over, excluding pregnant or lactating women, and data from 1,405 males and 2,102 females were analyzed. The mean ages were 63.5 and 62.4, respectively. Nutrients intake was evaluated from a semi-weighted, 1-d household dietary record. When the subjects were categorized into tertiles based on their vitamin E intake, higher vitamin E intake was associated with a lower percentage of subjects with hypertension (p for trend=0.01). Subjects with higher vitamin E intake had higher energy intake-adjusted intake of other nutrients which have been considered to be related to hypertension such as potassium, magnesium, and vitamin C. Logistic regression analysis was done with the low tertile of vitamin E intake as the reference. The medium and high tertiles of vitamin E intake were associated with a significantly lower odds ratio for hypertension, 0.73 (95% CI; 0.62-0.87) for the former and 0.81 (95% CI; 0.69-0.96) for the latter. Additional analyses, one adjusted for the indices associated with hypertension and one excluding the subjects with vitamin E supplementation, have yielded the similar results. In summary, re-analysis of data from NHNS has revealed that higher vitamin E intake was significantly associated with lower prevalence of hypertension.

Patients' perception on the nutritional therapy for diabetic nephropathy.

Low protein diet (LPD) plays an important role in preventing the progression of diabetic nephropathy. However, it is a great burden to the patients. In this paper, we have studied the quality of life (QOL) in such patients. The study subjects were 59 patients (male 38, female 21) with type 2 diabetes. The patients were classified into tertiles based on their protein intake (g/kg BW). Scores from the diet-related QOL questionnaire were summarized by principal component analysis into four components; mental health, less burden, satisfaction and merit, and less social restriction. Higher protein intake was associated with less burden and less social restriction. In multiple regression analysis, the significant predictors for the "less burden" component were higher protein intake/BW and estimated glomerular filtration rate (eGFR). In summary, registered dietitians and clinicians must keep in mind that LPD is a serious burden to the patients and efforts must be made to minimize their burden in order to avoid discontinuation.

Effect of vitamin D supplementation in the institutionalized elderly.

An intervention study with vitamin D supplementation was conducted in order to study the amount of vitamin D required in the elderly. Sixty-four institutionalized elderly were randomly assigned to two groups: group (A) to take a beverage containing 200 mg calcium daily, and group (B) to take a beverage containing 200 mg calcium and 5 microg vitamin D daily for 30 days. Prior to the study, the subjects' average vitamin D intake was 7.3 microg/day, which is approximately 150% of the current adequate intake (AI), however their mean plasma 25 OH-D level at baseline was only 12 ng/mL, strongly indicating hypovitaminosis D. During the study, average plasma 25 OH-D concentration significantly increased to 14.7 ng/mL in group (B), but not in group (A). However, group (B) was still in the hypovitaminosis range. Thus, daily intake exceeding the current AI of 5 microg is required for the institutionalized elderly.

Improvement of vitamin D status in Japanese institutionalized elderly by supplementation with 800 IU of vitamin D(3).

To study the adequate intake (AI) for vitamin D in the elderly, we have performed an intervention study with 800 IU/d of vitamin D(3) in the institutionalized elderly. Sixty-two institutionalized elderly were randomly assigned to two groups; receiving either supplements of 200 mg calcium plus 800 IU vitamin D(3)/d (Ca+VD group), or supplements of 200 mg calcium/d (Ca group) for 30 d in October. Serum concentrations of 25-hydroxyvitamin D (25OH-D), parathyroid hormone (PTH), and bone turnover markers were measured before and after intervention. Average dietary vitamin D intake during the intervention period was approximately 300 IU/d in both groups, exceeding the AI in Dietary Reference Intakes for Japanese 2005 of 200 IU/d. In both groups, mean serum 25OH-D level at baseline fell into the hypovitaminosis D range (9.7 ng/mL), despite apparently adequate vitamin D intake. Serum PTH level at baseline was within the reference range. Mean serum 25OH-D concentration significantly increased to 19.3 ng/mL in the Ca+VD group and to 11.1 ng/mL in the Ca group. Post intervention serum 25OH-D level was significantly higher in the Ca+VD group than in the Ca group (p<0.001). In 53 subjects (85.5%) who took more than 80% of their supplements for 30 d, serum PTH level in the Ca+VD group was significantly lower than in the Ca groups (p=0.05). Bone turnover markers were not significantly changed after intervention in either group. Daily supplementation of 800 IU vitamin D(3) was considered effective in the institutionalized elderly with minimal chance of sun exposure, but further studies with longer duration are necessary.