Lower Serum 25OHD Concentrations Research Articles

Motor imagery of gait in non-demented older community-dwellers: performance depends on serum 25-hydroxyvitamin D concentrations.

Hypovitaminosis D has been associated with poorer physical and cognitive performances in older adults. The objectives of this study were (1) to measure and compare the time to perform (pTUG) and to imagine (iTUG) the Timed "Up & Go" test (TUG) test, and the time difference between these two performances (i.e., TUG delta time) in non-demented community-dwelling older adults with and without lower serum 25-hydroxyvitamin D (25OHD) concentrations and (2) to examine the association between the TUG delta time and serum 25OHD concentrations. Durations of pTUG, iTUG and TUG delta time, and serum 25OHD concentrations (severe insufficiency <10 ng/mL; moderate insufficiency: 10-30 ng/mL; normal status >30 ng/mL) were measured in 359 non-demented participants (mean age 70.4 ± 4.8 years; 40.7 % women). Participants with severe 25OHD insufficiency (15.6 %) had higher TUG delta time compared to those with moderate insufficiency (P = 0.010) and normal status (P = 0.048). TUG delta time was negatively associated with serum 25OHD concentrations (P < 0.010). Accurate motor imagery of gait was explained in part by serum 25OHD concentrations, increased discrepancy between pTUG and iTUG being associated with lower serum 25OHD concentrations.

Vitamin D Status and Bone Mineral Density in African American Children With Crohn Disease

Vitamin D deficiency and low bone mineral density (BMD) are complications of inflammatory bowel disease. Vitamin D deficiency is more prevalent among African Americans compared with whites. There are little data comparing differences in serum 25-hydroxyvitamin D (25OHD) concentrations and BMD between African American and white children with Crohn disease (CD). We compared serum 25OHD concentrations of African American children with CD (n = 52) to white children with CD (n = 64) and healthy African American controls (n = 40). We also analyzed BMD using dual-energy x-ray absorptiometry results from our pediatric CD population. African American children with CD had lower serum 25OHD concentrations (16.1 [95% confidence interval, CI 14.5-17.9] ng/mL) than whites with CD (22.3 [95% CI 20.2-24.6] ng/mL; P < 0.001). African Americans with CD and controls exhibited similar serum 25OHD concentration (16.1 [95% CI 14.5-17.9] vs 16.3 [95% CI 14.4-18.4] ng/mL; NS). African Americans with CD exhibited no difference in serum 25OHD concentration when controlling for seasonality, disease severity, and surgical history, although serum 25OHD concentration was significantly decreased in overweight children (body mass index ≥85%, P = 0.003). Multiple regression analysis demonstrated that obese African American girls with CD had the lowest serum 25OHD concentrations (9.6 [95% CI 6.8-13.5] ng/mL). BMD was comparable between African American and white children with CD (z score -0.4 ± 0.9 vs -0.7 ± 1.2; NS). African American children with CD are more likely to have vitamin D deficiency compared with white children with CD, but have similar BMD. CD disease severity and history of surgery do not affect serum 25OHD concentrations among African American children with CD. African American children have low serum 25OHD concentrations, independent of CD, compared with white children. Future research should focus on how race affects vitamin D status and BMD in children with CD.

Vitamin D Status and Bone Mineral Density in African-American Children with Crohnʼs Disease

Purpose: Vitamin D deficiency and low bone mineral density (BMD) are complications of inflammatory bowel disease. Vitamin D deficiency is more prevalent among individuals of color, compared to Caucasians. There is little data comparing differences in serum 25-hydroxyvitamin D (25OHD) concentrations and BMD between African-American and Caucasian children with Crohn's Disease (CD). Methods: We compared serum 25OHD concentrations of African-American children with CD (n=52) to Caucasian children with CD (n=64) and healthy African-American controls (n=40). We also analyzed BMD using dual energy x-ray absorptiometry (DXA) results from our pediatric CD population. Results: African-American children with CD had lower serum 25OHD concentrations (16.1 [14.5-17.9; 95% CI] ng/mL) than Caucasians with CD (22.3 [20.2-24.6; 95% CI] ng/mL; p<0.001). African-Americans with CD and controls exhibited similar serum 25OHD concentration (16.1 [14.5-17.9, 95%CI] vs. 16.3 [14.4-18.4, 95%CI] ng/mL; NS). African-Americans with CD exhibited no difference in serum 25OHD concentration when controlling for seasonality, disease severity, and surgical history, though serum 25OHD concentration was significantly decreased in overweight children (BMI≥85%, p =0.003). Multiple regression analysis demonstrated that obese African-American females with CD had the lowest serum 25OHD concentrations (9.6 [6.8-13.5, 95%CI] ng/mL). BMD was comparable between African-American and Caucasian children with CD (Z score -0.4 ± 0.9 vs -0.7 ± 1.2; NS). Conclusion: African-American children with CD are more likely to have vitamin D deficiency compared to Caucasian with CD, but have similar BMD. CD disease severity and history of surgery do not affect serum 25OHD concentrations among African-American children with CD. African-American children have low serum 25OHD concentrations, independent of CD, compared to Caucasian children. Future research should focus on how race affects vitamin D status and BMD in children with CD.

Biology of gait control

Adverse neuromuscular events have been described in case of low serum 25-hydroxyvitamin D (25OHD) concentrations, suggesting that vitamin D may be involved in gait stability. The objective of this cross-sectional study was to examine the association between stride-to-stride variability of stride time (STV) and serum 25OHD concentration in adults aged 65 years and older. STV and 25OHD concentration were assessed in 411 community-dwelling older adults (mean age 70.4 ± 1.8 years, 57.9% women). The following established 25OHD thresholds were used: severe 25OHD insufficiency <10 ng/mL, moderate 10-30 ng/mL, and normal >30 ng/mL. Age, number of drugs used per day, use of psychoactive drugs, depressive symptoms, cognitive decline, history of falls, distance visual acuity, lower limb proprioception, center of mass (CoM) motion, and walking speed were considered as potential confounders. A total of 16.6% (n = 68) of subjects had severe 25OHD insufficiency, 70.3% (n = 289) moderate insufficiency, and 13.1% (n = 54) normal concentrations. In the full adjusted and the stepwise backward linear regression models, high STV (worse performance) was associated with severe 25OHD insufficiency (p = 0.028 and p = 0.044, respectively), high CoM motion (p = 0.031 and p = 0.014, respectively), and low lower limb proprioception score (p = 0.017 and p = 0.008, respectively). The stepwise backward regression model also showed that high STV was associated with female gender (p = 0.041). Low serum 25OHD concentrations were associated with high STV reflecting a disturbed gait control. This association could be explained by a possible action of vitamin D on different components involved in gait control.

Vitamin D intakes in North America and Asia-Pacific countries are not sufficient to prevent vitamin D insufficiency

Worldwide, vitamin D status is suboptimal relative to circulating levels of 25-hydroxyvitamin D (25OHD) needed to prevent a variety of chronic conditions, however, it has long been assumed that dietary intake is sufficient to meet needs when sun exposure is limited. In the USA, mean vitamin D intake from foods is close to 5μg, the Dietary Reference Intake (DRI) recommendation for persons up to 50 years; however, the amount of vitamin D needed to maintain a sufficient 25OHD level during winter is >12.5μg, and that needed for darkly pigmented, veiled, or sun protected persons is >50μg. In the USA, most vitamin D intake from foods is provided by fortification. Canada and New Zealand have fewer fortified choices, and intakes are correspondingly lower. Supplement use can increase mean intake to >12.5μg but does not always reach those who need it most. Serum 25OHD levels in New Zealand reveal much more insufficiency than expected, especially for Pacific people and Mäori; low serum 25OHD concentrations are seen throughout the Asia-Pacific region. Fortification and supplementation may be effective to achieve intakes of 12.5μg vitamin D in some of the population, but for many achieving the amount needed in the absence of skin synthesis requires intakes above the current upper level for vitamin D of 50μg.

RETRACTED: Risk factors for hip fracture among elderly patients with Alzheimer's disease

Incidence of hip fracture among patients with Alzheimer's disease (AD), especially in elderly patients, is high. To analyze risk factors of hip fracture, we prospectively studied a cohort of elderly female patients with AD. Subjects studied were 225 female patients with AD, and the average age was 76 years old. At baseline, we recorded body mass index (BMI), a score of Mini-Mental State Examination (MMSE) and bone mineral density (BMD), and measured serum concentrations of ionized calcium, intact parathyroid hormone (PTH), pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP), intact bone Gla protein (BGP), 25-hydroxyvitamin (25-OHD) and 1, 25-dihydroxyvitamin D (1, 25-[OH] 2D). The patients were followed for 2 years. During the 2-year study, hip fractures occurred in 29 patients. We compared baseline variables between the 29 patients with and 176 patients without hip fracture. AD patients with lower BMD, low concentrations of serum ionized calcium and 25-OHD (mean 3.0 ng/ml) with compensatory hyperparathyroidism were found to have an increased risk of hip fracture. Also, concentrations of serum ICTP and BGP were higher in the fracture group than in the nonfracture group. Elderly female AD patients with low BMD and serum 25-OHD concentrations <5 ng/ml with secondary hyperparathyroidism have a high risk of hip fracture, and the risk may be reduced by vitamin D supplementation.

Vitamin D Metabolism in Pre‐Operative Extrahepatic Biliary Atresia

In order to clarify the pathogenesis of rickets in preoperative patients with extrahepatic biliary atresia, we evaluated baseline serum 25-OHD and 1,25(OH)2D levels and correlated serum 25-OHD levels with increase in age and season of birth in 16 preoperative patients. Further, parenteral vitamin D2 tolerance tests were performed in 5 cases. Serum 25-OHD and 1,25(OH)2D levels were significantly lower than those in 15 normal controls. There was a negative correlation between the serum 25-OHD levels and increase in age. The patients born during the winter had lower serum 25-OHD concentrations than those born in summer. The mean value of increased 25-OHD levels after the parenteral vitamin D2 tolerance tests did not differ from that of 6 controls. Since there was no impairment of vitamin D 25-hydroxylation, the reduction in serum 25-OHD may therefore be mainly due to disturbed intestinal vitamin D absorption. It was also concluded that season of birth and increase in age are pathogenic factors in the etiology of rickets in preoperative patients with extrahepatic biliary atresia.

Randomized study of sunshine exposure and serum 25-OHD in breast-fed infants in Beijing, China

The hypothesis that breastfed infants in Beijing, China, have low vitamin D status and that sunshine exposure increases serum 25-hydroxyvitamin D (25-OHD) concentrations was tested in a randomized prospective study involving 42 healthy infants 1-8 months of age. 24 controls were exposed to the usual amount of sunshine, while the 18 cases were provided with 2 hours of sunshine/day. All infants were being breastfed without vitamin D supplementation. Serum 25-OHD concentrations at entry into the study ranged from 3-61 ng/ml and increased with age. 3 infants in each group were diagnosed as having rickets. Serum 25-OHD concentrations did not change significantly during the 2-month study period among controls, while serum 25-OHD values increased significantly in the experimental group. Final infant serum 25-OHD concentrations correlated with ultraviolet exposure scores (p.001). The estimate of ultraviolet score needed to maintain a serum 25-OHD of 11 ng/ml was 2.4 (24 minutes/day with only the face uncovered). Rickets has been reported in as many as 18% of Chinese infants and seems to especially affect those 2-4 months of age. The fact that not all infants with rickets in this study had low 25-OHD concentrations suggests 2 possibilities: 1) not all rickets is necessarily related to a vitamin D deficiency, or 2) serum 25-OHD concentrations are not the best indicator of vitamin D status. The low serum 25-OHD concentrations in many Chinese infants may be related to low maternal milk vitamin D content resulting from the lack of vitamin D food fortification. Overall, these results suggest that the diet of breastfed Chinese infants should be supplemented with orally administered vitamin D.

Absorption, dosage, and effect on mineral homeostasis of 25-hydroxycholecalciferol in premature infants: Comparison with 400 and 800 IU vitamin D 2 supplementation

Because the efficiency of vitamin D absorption or hepatic uptake and 25-hydroxylation appears decreased in very premature infants, the routine use of 25-hydroxycholecalciferol (25-OHD3) supplementation has been suggested. Absorption studies of a 3 micrograms/kg orally administered dose of 25-OHD3 showed peak serum 25-hydroxyvitamin D2 and -vitamin D3 (25-OHD) concentrations at 4 to 8 hours similar in timing but of lesser magnitude to those seen in adults. Administration of 1 microgram/kg birth weight/day of 25-OHD3 corrected moderately low, but not very low serum (25-OHD) concentrations, and 2 micrograms/kg BW/day resulted in rapid and sustained increase in serum 25-OHD. Administration of 800 IU ergocalciferol (D2) also produced significantly higher serum 25-OHD concentrations than those in infants given 400 IU vitamin D2, but increases in serum 25-OHD were more gradual than in infants given 25-OHD3. In treatment trials with infants weighing less than 1500 gm, those given 800 IU D2, compared with those given 400 IU D2, had higher serum calcium concentrations and less frequent moderate or severe hypomineralization. Infants given 2 micrograms/kg BW 25-OHD3 had a significant increase in serum phosphorus values, but a decrease in serum calcium and magnesium concentrations, and parathyroid hormone also was suppressed to low normal values. The frequency of moderate to severe hypomineralization remained the same as in infants given 400 IU D2. In a subgroup of infants, serum 1,25-dihydroxyvitamin D was elevated over adult values, both in infants given 25-OHD3 (68.5 +/- 8.4 pg/ml) and in infants given vitamin D2 (60 +/- 6.7 pg/ml). Serum vitamin D concentrations were undetectable in four of six infants receiving 25-OHD3, but were elevated (5 to 31 ng/ml) in four infants receiving vitamin D2. Although 800 to 1000 IU D2 can be recommended as routine vitamin D supplementation in very premature infants fed standard formula, the use of 25-OHD3 requires further study.

Serum concentrations of vitamin D metabolites in untreated tuberculosis.

A prospective study of 50 consecutive patients presenting with tuberculosis has shown that patients have on average lower serum concentrations of 25-hydroxycholecalciferol (25-OHD) than healthy matched controls. No difference was shown in serum 1,25-(OH)2D, 24,25-(OH)2D, or parathyroid hormone. Uncorrected serum calcium was lower in the patient group but identical when correction concentrations were made for albumin. Serum liver enzyme concentrations were significantly higher in the patient population. Low serum vitamin D concentrations may be a consequence of disease. The possibility that low serum 25-OHD concentrations may predispose to tuberculosis infection cannot, however, be excluded. Prolonged treatment with isoniazid or rifampicin, both of which have been shown to reduce serum 25-OHD, may increase the risk of vitamin D deficiency and consequent osteomalacia in groups of patients most at risk, such as those of Indian subcontinental ethnic origin.