Plasma 25-Hydroxyvitamin D Responses of Younger and Older Men to Three Weeks of Supplementation with 1800 IU/day of Vitamin D

Objective: The objective of this study was to compare changes in plasma 25-hydroxyvitamin D (25(OH)D) levels of younger and older men after three weeks of oral vitamin D supplementation.

Methods: Nine younger men (22 to 28 years) and nine older men (65 to 73 years) with self-reported vitamin D intakes below 200 IU/d were enrolled in February and randomized to 1800 IU/d of ergocalciferol (vitamin D₂, n=11) or to a control group (n=7) and followed for three weeks. Blood was collected at baseline, and after one, two and three weeks for measurement of plasma concentrations of total 25(OH)D, 25(OH)D₂ and 25(OH)D₃.

Results: In both the younger and older supplemented men, 25(OH)D₂ and total 25(OH)D concentrations increased significantly during the study, whereas values of these metabolites did not change in younger or older control subjects. No group showed significant changes in 25-hydroxyvitamin D₃. There was a significant interaction between age group and supplement group, suggesting that the effect of vitamin D₂ supplementation on changes in 25(OH)D₂ changes with age. The mean increase in 25(OH)D₂ was greater in the younger supplemented men than in the older supplemented men (37±9 nmol/L vs. 19.5 nmol/L, p=0.027), and this accounted for their significantly greater increase in total 25(OH)D.

Conclusion: These data are consistent with an age-related decline in the absorption, transport or liver hydroxylation of orally-consumed vitamin D.     

Factors Affecting 25-Hydroxyvitamin D Concentration in Response to Vitamin D Supplementation

Sun exposure is the main source of vitamin D. Due to many lifestyle risk factors vitamin D deficiency/insufficiency is becoming a worldwide health problem. Low 25(OH)D concentration is associated with adverse musculoskeletal and non-musculoskeletal health outcomes. Vitamin D supplementation is currently the best approach to treat deficiency and to maintain adequacy. In response to a given dose of vitamin D, the effect on 25(OH)D concentration differs between individuals, and it is imperative that factors affecting this response be identified. For this review, a comprehensive literature search was conducted to identify those factors and to explore their significance in relation to circulating 25(OH)D response to vitamin D supplementation. The effect of several demographic/biological factors such as baseline 25(OH)D, aging, body mass index(BMI)/body fat percentage, ethnicity, calcium intake, genetics, oestrogen use, dietary fat content and composition, and some diseases and medications has been addressed. Furthermore, strategies employed by researchers or health care providers (type, dose and duration of vitamin D supplementation) and environment (season) are other contributing factors. With the exception of baseline 25(OH)D, BMI/body fat percentage, dose and type of vitamin D, the relative importance of other factors and the mechanisms by which these factors may affect the response remains to be determined.     

Effects of Vitamin D Supplementation on 24-Hour Blood Pressure in Patients with Low 25-Hydroxyvitamin D Levels: A Randomized Controlled Trial

Accumulating evidence suggests that potential cardiovascular benefits of vitamin D supplementation may be restricted to individuals with very low 25-hydroxyvitamin D (25(OH)D) concentrations; the effect of vitamin D on blood pressure (BP) remains unclear. We addressed this issue in a post hoc analysis of the double-blind, randomized, placebo-controlled Styrian Vitamin D Hypertension Trial (2011–2014) with 200 hypertensive patients with 25(OH)D levels <30 ng/mL. We evaluated whether 2800 IU of vitamin D3/day or placebo (1:1) for 8 weeks affects 24-hour systolic ambulatory BP in patients with 25(OH)D concentrations <20 ng/mL, <16 ng/mL, and <12 ng/mL and whether achieved 25(OH)D concentrations were associated with BP measures. Taking into account correction for multiple testing, p values < 0.0026 were considered significant. No significant treatment effects on 24-hour BP were observed when different baseline 25(OH)D thresholds were used (all p-values > 0.30). However, there was a marginally significant trend towards an inverse association between the achieved 25(OH)D level with 24-hour systolic BP (−0.196 per ng/mL 25(OH)D, 95% CI (−0.325 to −0.067); p = 0.003). In conclusion, we could not document the antihypertensive effects of vitamin D in vitamin D-deficient individuals, but the association between achieved 25(OH)D concentrations and BP warrants further investigations on cardiovascular benefits of vitamin D in severe vitamin D deficiency.     

Moderate Amounts of Vitamin D3 in Supplements are Effective in Raising Serum 25-Hydroxyvitamin D from Low Baseline Levels in Adults: A Systematic Review

There is controversy surrounding the designation of vitamin D adequacy as defined by circulating levels of the metabolite 25-hydroxyvitamin D (25(OH)D). Depending on the cutoff level chosen, dietary intakes of vitamin D may or may not provide sufficient impact upon vitamin D status measured as improvement in serum levels of 25(OH)D. We sought to examine whether modest daily doses (5–20 μg) as found in fortified foods or multivitamin supplements had a measureable impact on vitamin D status, defined as moving from below to above 50 nmol/L, or from less than 30 nmol/L to above 30 nmol/L. Published literature was searched for relevant articles describing randomized controlled trials. Exclusion criteria were: studies not involving humans; review articles; studies lacking blood level data pre- and post-treatment; no control group; bolus treatments (weekly, monthly, yearly); vitamin D <5 μg or >20 μg; baseline 25(OH)D ≥75 nmol/L; subjects not defined as healthy; studies <8 weeks; and age <19 years. Of the 127 studies retrieved, 18 publications with 25 separate comparisons met criteria. The mean rate constant, defined as change in 25(OH)D in nmol/L per μg vitamin D administered, was calculated as 2.19 ± 0.97 nmol/L per μg. There was a significant negative correlation (r = −0.65, p = 0.0004) between rate constant and administered dose. To determine impact of the dose reflecting the Estimated Average Requirement (EAR) of 10 μg administered in nine studies (10 comparisons), in every case mean 25(OH)D status rose either from “insufficient” (30–50 nmol/L) to “sufficient” (>50 nmol/L) or from “deficient” (<30 nmol/L) to “insufficient” (>30 but <50 nmol/L). Our study shows that when baseline levels of groups were <75 nmol/L, for every microgram of vitamin D provided, 25(OH)D levels can be raised by 2 nmol/L; and further, when groups were deficient or insufficient in vitamin D, there was significant value in providing additional 10 μg per day of vitamin D.     

Etiology of Anemia in Older Mexican Adults: The Role of Hepcidin,Vitamin A and Vitamin D

Anemia in older adults is a growing public health issue in Mexico; however, its etiology remains largely unknown. Vitamin A deficiency (VAD) and vitamin D deficiency (VDD) have been implicated in the development of anemia, though by different mechanisms. The aim of this study is to analyze the etiology of anemia and anemia-related factors in older Mexican adults. This is a cross-sectional study of 803 older adults from the southern region of Mexico in 2015. The anemia etiologies analyzed were chronic kidney disease (CKD), nutritional deficiencies (ND), anemia of inflammation (AI), anemia of multiple causes (AMC) and unexplained anemia (UEA). VAD was considered to be s-retinol ≤ 20 μg/dL, and VDD if 25(OH)D < 50 nmol/L. IL-6 and hepcidin were also measured. Multinomial regression models were generated and adjusted for confounders. Anemia was present in 35.7% of OA, independent of sex. UEA, CKD, AI and ND were confirmed in 45%, 29.3%, 14.6% and 7% of older adults with anemia, respectively. Hepcidin and log IL-6 were associated with AI (p < 0.05) and CKD (p < 0.001). VAD was associated with AI (p < 0.001), and VDD with ND and AMC (p < 0.05). Log-IL6 was associated with UEA (p < 0.001). In conclusion, anemia in older adults has an inflammatory component. VAD was associated to AI and VDD with ND and AMC.     

The Importance of Dose,Frequency and Duration of Vitamin D Supplementation for Plasma 25-Hydroxyvitamin D

The importance of dose, frequency and duration of vitamin D supplementation for plasma 25(OH)D levels is not well described and rarely reported for supplementation that exceeds 2000 IU per day. The objective is to examine dose, frequency and duration of supplementation in relation to plasma 25(OH)D in a large population-based sample. We accessed data on 2714 volunteers that contributed to 4224 visits and applied multilevel regression. Compared to not using supplements, a minimum regimen of 1000–2000 IU once or twice per week for one month was not effective in raising 25(OH)D. Compared to this minimum regimen, higher doses of 2000–3000, 3000–4000, and 5000 IU or more were associated with a 7.49, 13.19 and 30.22 nmol/L 25(OH)D increase, respectively; frequencies of three to four, five to six and seven times/week were associated with a 5.44, 16.52 and 30.69 nmol/L increase, respectively; and supplementation of five months or longer was associated with an increase of 6.68 nmol/L (p < 0.01 for all). Age, body weight, physical activity, smoking, and self-rated health were significantly associated with 25(OH)D. Whereas dose, frequency and duration of supplementation are important to healthy subjects committed to optimizing their nutritional status, to the design of clinical trials, individual characteristics and lifestyle contribute substantially to 25(OH)D.     

Effect of Calcitriol Supplementation on Blood Pressure in Older Adults

Recent studies suggest that vitamin D plays an important role in the control of blood pressure. Unfortunately, because older adults are more likely to have low 25-hydroxyvitamin-D [25(OH)D] levels, this study investigated whether calcitriol supplementation reduces blood pressure in older adults with hypertension. The design was a double-blind placebo-controlled randomized clinical trial with 36 randomly assigned subjects (71.7?±?10 years). Blood pressure and serum levels of 25(OH)D before and after calcitriol intervention (1,000 IU daily for 6 weeks; n?=?22) or placebo (n?=?23) for 6 weeks were analyzed. At the end of the study, the calcitriol group presented a significant decrease of systolic blood pressure [20.25 mmHg (p?=?0.001)] and diastolic blood pressure [7 mmHg (p?=?0.01)], compared with the placebo group. In conclusion, 1,000 IU/day of calcitriol for 6 weeks efficiently reduced systolic and diastolic blood pressure levels in this population of older adults presenting with high blood pressure (Clinical Trial Approbation NCT02047799).     

The Effects of Vitamin D-Enriched Mushrooms and Vitamin D3 on Cognitive Performance and Mood in Healthy Elderly Adults: A Randomised,Double-Blinded,Placebo-Controlled Trial

Despite abundant cross-sectional evidence that low vitamin D status is associated with risk of cognitive decline in ageing, interventional evidence for benefits of vitamin D supplementation is lacking. This study was a 6 month randomised, double-blinded placebo-controlled clinical trial of the effects of vitamin D3 (D3), enhanced vitamin D2 in a mushroom matrix (D2M), standard mushroom (SM) and placebo (PL) on cognition and mood in n = 436 healthy older male (49%) and female volunteers aged ≥ 60 years. Primary end points were change in serum vitamin D metabolites (25-OH-D, 25-OH-D2 and 25-OH-D3), cognitive performance, and mood over 24 weeks. Levels of total 25-OH-D and 25-OH-D3 were maintained in the D3 arm but decreased significantly (p < 0.05) in the remaining arms (D2M, SM and PL). Analysis also revealed differential changes in these metabolites depending on total vitamin D status at baseline. There were no significant effects of treatment on any of the measures of cognitive function or mood. Overall, the results show that daily supplementation of ~600 IU of vitamin D3 was sufficient to maintain 25-OH-D throughout winter months, but in contrast to existing cross-sectional studies there was no support for benefit of vitamin D supplementation for mood or cognition in healthy elderly people.     

Positive Effects of Vitamin D Supplementation in Patients Hospitalized for COVID-19: A Randomized,Double-Blind,Placebo-Controlled Trial

Retrospective studies showed a relationship between vitamin D status and COVID-19 severity and mortality, with an inverse relation between SARS-CoV-2 positivity and circulating calcifediol levels. The objective of this pilot study was to investigate the effect of vitamin D supplementation on the length of hospital stay and clinical improvement in patients with vitamin D deficiency hospitalized with COVID-19. The study was randomized, double blind and placebo controlled. A total of 50 subjects were enrolled and received, in addition to the best available COVID therapy, either vitamin D (25,000 IU per day over 4 consecutive days, followed by 25,000 IU per week up to 6 weeks) or placebo. The length of hospital stay decreased significantly in the vitamin D group compared to the placebo group (4 days vs. 8 days; p = 0.003). At Day 7, a significantly lower percentage of patients were still hospitalized in the vitamin D group compared to the placebo group (19% vs. 54%; p = 0.0161), and none of the patients treated with vitamin D were hospitalized after 21 days compared to 14% of the patients treated with placebo. Vitamin D significantly reduced the duration of supplemental oxygen among the patients who needed it (4 days vs. 7 days in the placebo group; p = 0.012) and significantly improved the clinical recovery of the patients, as assessed by the WHO scale (p = 0.0048). In conclusion, this study demonstrated that the clinical outcome of COVID-19 patients requiring hospitalization was improved by administration of vitamin D.     

Optimal Vitamin D Supplementation Doses that Minimize the Risk for Both Low and High Serum 25-Hydroxyvitamin D Concentrations in the General Population

The Recommended Dietary Allowance (RDA) is the nutrient intake considered to be sufficient to meet the requirements of 97.5% of the population. Recent reports revealed a statistical error in the calculation of the RDA for vitamin D opening the question of what the recommendation should be. We took a dual approach to answer this question: (1) we aggregated 108 published estimates on vitamin D supplementation and vitamin D status; and (2) we analyzed 13,987 observations of program participants. The aggregation of published data revealed that 2909 IU of vitamin D per day is needed to achieve serum 25-hydroxyvitamin D (25(OH)D) concentrations of 50 nmol/L or more in 97.5% of healthy individuals. For normal weight, overweight and obese program participants this was 3094, 4450 and 7248 IU respectively. These supplementation doses would also result in 2.5% of normal weight, overweight and obese participants having 25(OH)D concentrations above 210, 200 and 214 nmol/L respectively. As these concentrations are high, an approach that minimizes the risk for both low and high concentrations seems desirable. With this approach we estimated, for example, that doses of 1885, 2802 and 6235 IU per day are required for normal weight, overweight and obese individuals respectively to achieve natural 25(OH)D concentrations (defined as 58 to 171 nmol/L). In conclusion, the large extent of variability in 25(OH)D concentrations makes a RDA for vitamin D neither desirable nor feasible. We therefore propose recommendations be articulated in the form of an optimal intake that minimizes the risk for both low and high serum 25(OH)D concentrations. This contribution includes body weight specific recommendations for optimal intakes for various combinations of lower and upper 25(OH)D concentration targets.     

Vitamin D Deficiency and Insufficiency in the Georgia Older Americans Nutrition Program

ABSTRACT

Serum 25-hydroxyvitamin D (25(OH)D) status in older adults enrolled in community-based meal programs is not well characterized. The objective was to identify predictors of poor serum 25(OH)D status and the response to vitamin D supplementation in a convenience sample from the Older Americans Act Nutrition Program (OAANP) in northeast Georgia (N = 158, mean age = 77 years, 81% women, 69% Caucasian, 31% African American). Mean serum 25(OH)D was 55 nmol/l, and intakes of vitamin D and calcium from foods were very low. Vitamin D insufficiency (25(OH)D 25- < 50 nmol/l) occurred in 36.7%. Vitamin D deficiency occurred in 8.2% (25(OH)D < 25 nmol/l) and was associated with low milk intake, low sunlight exposure, receiving meals at home, tobacco use, depression, dementia, antianxiety medication, poor instrumental activities of daily living, and low calf circumference (p ≤ 0.05). When non-supplement users (n = 28) were given a multivitamin with vitamin D (10 µg/d) and calcium (450 mg/d) for 4 months, 25(OH)D increased from 50 to 78 nmol/l, the prevalence of poor vitamin D status (25(OH)D < 50 nmol/l) decreased from 61% to 14%, and serum alkaline phosphatase decreased by 10% (p < 0.01). High body weight appeared to attenuate the increase in 25(OH)D in response to the multivitamin supplement (p ≤ 0.05). In conclusion, OAANP services did not prevent poor vitamin D and calcium status, but a supplement with vitamin D and calcium was beneficial.     

Vitamin D and COVID-19 Severity in Hospitalized Older Patients: Potential Benefit of Prehospital Vitamin D Supplementation

Studies involving the associations between vitamin D supplementation taken before the onset of COVID-19 infection and the clinical outcomes are still scarce and this issue remains controversial. This study aimed to assess the relationships between vitamin D (VitD) status and supplementation and coronavirus disease 2019 (COVID-19) severity in older adults (average age of 78 years) hospitalized for COVID-19. We conducted an observational retrospective cohort study with 228 older hospitalized patients during the first wave of the COVID-19 pandemic. The outcomes were in-hospital mortality secondary to COVID-19 or critically severe COVID-19. A logistic regression analysis was conducted to test whether pre-hospital VitD supplementation was independently associated with severity. In this study, 46% of patients developed a severe form and the overall in-hospital mortality was 15%. Sixty-six (29%) patients received a VitD supplement during the 3 months preceding the infection onset. Additionally, a VitD supplement was associated with fewer severe COVID-19 forms (OR = 0.426, p = 0.0135) and intensive care unit (ICU) admissions (OR = 0.341, p = 0.0076). As expected, age > 70 years, male gender and BMI ≥ 35 kg/m² were independent risk factors for severe forms of COVID-19. No relationship between serum 25(OH)D levels and the severity of the COVID-19 was identified. VitD supplementation taken during the 3 months preceding the infection onset may have a protective effect on the development of severe COVID-19 forms in older adults. Randomized controlled trials and large-scale cohort studies are necessary to strengthen this observation.     

Adequate Dietary Intake and Vitamin D Supplementation: A Study of Their Relative Importance in Determining Serum Vitamin D and Ferritin Concentrations during Pregnancy

Vitamin D is essential for human health. However, it is not clear if vitamin D supplementation is necessary for all pregnant women. This study examines the relative importance of dietary patterns and vitamin D supplementation frequency in determining serum 25-hydroxyvitamin D (25(OH)D) and ferritin concentrations among pregnant women in Hong Kong, China. A total of 572 healthy women were recruited from antenatal clinics at 25–35 weeks pregnant. Participants completed an electronic version of the food frequency questionnaire and a web questionnaire on supplement use. Their blood samples were tested for serum 25(OH)D and ferritin. The associations of dietary patterns and vitamin D supplementation frequency with serum 25(OH)D and ferritin concentrations were analyzed using moderated hierarchical regression. Two dietary patterns were identified. The adequate dietary intake was characterized by the high probability of meeting recommended daily food group servings, whereas the inadequate dietary intake was characterized by inadequate consumption of vegetables, fruits, meat, fish, and eggs, or alternatives. The association between adequate dietary intake and serum ferritin concentrations was independent of vitamin D supplementation frequency (β = 0.05, p = 0.035), but dietary patterns interacted with vitamin D supplementation frequency to determine serum 25(OH)D concentrations (β = −13.22, p = 0.014). The current study presents evidence on the relative importance of dietary patterns and vitamin D supplementation in maintaining sufficient vitamin D and iron in pregnancy. Antenatal nutrition counselling services should be provided to pregnant women who show signs of inadequate dietary intake.     

A Systematic Review of Vitamin D Status and Dietary Intake in Various Slovenian Populations

AimVitamin D (VitD) is involved in calcium and phosphate homeostasis, bone health, and normal functioning of the immune system. VitD status is monitored using serum 25-hydroxy-vitamin D (25(OH)D) as a biomarker. Serum 25(OH)D concentrations below 30 nmol/L indicate VitD deficiency and below 50 nmol/L indicate insufficiency. VitD can be synthesised endogenously in human skin when exposed to ultraviolet B (UVB) radiation. In the absence of sufficient UVB-light exposure, VitD intake becomes the main source of VitD, with a recommended daily intake of 20 μg. The aim of this study was to conduct a review and meta-analysis on the abovementioned topics, focusing on scientific studies in various Slovenian populations.MethodsWe conducted a systematic review and meta-analysis of published scientific papers, academic theses, or conference contributions reporting serum 25(OH)D status and VitD intake across various Slovenian populations. A search was carried out using Web of Science, Scopus, Medline, and the Slovenian library database.ResultsWe identified 43 pertinent studies that addressed 25(OH)D status and 16 that addressed VitD intake. Serum 25(OH)D status was generally low across all populations, and notable seasonal variability was observed. VitD intakes were below 5 μg in all studies.ConclusionsA general observation is that various population groups across Slovenia are at high risk of vitamin D insufficiency and deficiency, particularly during wintertime. Regarding vitamin D intake, all included studies reported daily intakes below the recommended level. We also identified key research gaps that need to be addressed to support further public health decision-making.     

Randomized Controlled Trial of Exercise and Nutrition Supplementation on Physical and Cognitive Function in Older Chinese Adults Aged 50 Years and Older

ObjectivesTo assess whether a 24-week multidomain lifestyle intervention including a nutritional milk supplement and an exercise program had any effect on physical and cognitive function, self-rated health, and health-related quality of life in older Chinese adults.DesignRandomized controlled trial.Setting and participantsCommunity-living people aged 50 years and older.Methods180 participants (mean age 61 ± 6 years) were randomized to 24 weeks of exercise plus nutrition supplementation or no intervention. The primary outcome was gait speed, with additional physical and cognitive function measures, self-rated health, and health-related quality of life as secondary outcomes. Information collected also included dietary intake by 3-day dietary records, and blood sampling for renal function, glycated hemoglobin, serum vitamin B₁₂, 25-hydroxyvitamin D, and biochemical indices of bone turnover.ResultsThere was no significant group difference in the change of gait speed, muscle strength, muscle power, cardiovascular fitness, or cognitive function over time, either by intention-to-treat or per-protocol analysis. A significant time × group effect (P = .039) on self-rated health was detected, but there was no significant time or time × group difference in the change of physical and mental health-related quality of life measures over time. In addition, moderate physical activity level was greatly increased from baseline to 24 weeks in the intervention group compared with the control group.Conclusions and implicationsA 24-week exercise and nutrition supplementation program among community-living people in late midlife to early old age improved self-rated health and the overall level of physical activity, without objective improvements in physical and cognitive function.     

The Health Effects of Vitamin D and Probiotic Co-Supplementation: A Systematic Review of Randomized Controlled Trials

Evidence of synergic health effects of co-supplementation with vitamin D and probiotics is emerging. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses PRISMA statement, scientific databases and the grey literature were searched, and a narrative review and risk of bias assessment were conducted. Seven randomized controlled trials were included, which had low risk of bias. Six studies were double-blind, and once single-blind, extended over 6–12 weeks, and included 50–105 participants. Conditions explored included schizophrenia, gestational diabetes, type 2 diabetes and coronary heart disease, polycystic ovarian syndrome, osteopenia, irritable bowel syndrome (IBS), and infantile colic. Supplementation frequency was daily or bi-monthly, with mainly vitamin D3, and Lactobacillus, Bifidobacterium, and Streptococcus. Comparators were placebo, vitamin D, lower vitamin D dose, and probiotics and lower vitamin D dose. The co-supplementation yielded greater health benefits than its comparators did in all studies except in one assessing IBS. Beneficial effects included decreased disease severity, improved mental health, metabolic parameters, mainly insulin sensitivity, dyslipidemia, inflammation, and antioxidative capacity, and lower use of healthcare. Co-supplementation of vitamin D and probiotics generated greater health benefits than its comparators did. More studies in other diseases and various populations are needed to confirm these findings and to elucidate the optimal form, composition, and frequency of this co-supplementation.     

The Role of Vitamin D in Stroke Prevention and the Effects of Its Supplementation for Post-Stroke Rehabilitation: A Narrative Review

Hypovitaminosis D is a serious public health problem, representing an independent factor in mortality among the general population. Vitamin D deficiency may affect up to one billion people worldwide. Recently, the potential association between vitamin D levels and stroke has gained increasing attention. Many studies suggest that maintaining normal serum vitamin D levels is associated with improvement of the cardiovascular system and a reduction in stroke risk. As a neurosteroid, vitamin D influences brain development and function and immunomodulation and affects brain neuroplasticity. It supports many processes that maintain homeostasis in the body. As stroke is the second most common cause of death worldwide, more studies are needed to confirm the positive effects of vitamin D supplementation, its dosage at different stages of the disease, method of determination, and effect on stroke onset and recovery. Many studies on stroke survivors indicate that serum vitamin D levels only offer insignificant benefits and are not beneficial to recovery. This review article aims to highlight recent publications that have examined the potential of vitamin D supplementation to improve rehabilitation outcomes in stroke survivors. Particular attention has been paid to stroke prevention.     

学龄前儿童维生素A营养状况与干预效果观察

目的通过调查北京近郊农村学龄前儿童维生素A摄入与血清维生素A水平,为评价和改善我国学龄前儿童维生素A营养状况提供依据.方法对北京近郊农村272名3～7岁儿童采用膳食记录法进行膳食调查,采用高效液相色谱法检测血清维生素A含量,对其中血清维生素A＜0.73μmol·L-1的30名儿童给予口服维生素A胶丸(每丸1.25万IU)每周2次,每次1丸,连续6周,同时对家长进行营养知识教育,干预结束后重复测定血清维生素A含量.结果受检儿童每日维生素A平均摄入量为384.3±227.0μgRE,仅占RNA的58.2%.血清VA含量平均为1.12±0.06μmol·L-1,其中血清维生素A＜1.05μmol·L-1占受检儿童的44.08%,并有6.12%受检儿童血清维生素A＜0.70μmol·L-1,血清维生素A正常者仅占55.92%.对血清维生素A＜0.73μmol·L-1的30名儿童给予VA干预后,血清VA提高至1.47μmol·L-1.结论在经济状况有了一定改善之后,学龄前儿童仍然存在着维生素A摄入不足,部分儿童血清维生素A水平较低,应予以重视和改善.     

Monitored Supplementation of Vitamin D in Preterm Infants: A Randomized Controlled Trial

Appropriate supplementation of vitamin D can affect infections, allergy, and mental and behavioral development. This study aimed to assess the effectiveness of monitored vitamin D supplementation in a population of preterm infants. 109 preterm infants (24 0/7–32 6/7 weeks of gestation) were randomized to receive 500 IU vitamin D standard therapy (n = 55; approximately 800–1000 IU from combined sources) or monitored therapy (n = 54; with an option of dose modification). 25-hydroxyvitamin D [25(OH)D] concentrations were measured at birth, 4 weeks of age, and 35, 40, and 52 ± 2 weeks of post-conceptional age (PCA). Vitamin D supplementation was discontinued in 23% of infants subjected to standard treatment due to increased potentially toxic 25(OH)D concentrations (>90 ng/mL) at 40 weeks of PCA. A significantly higher infants’ percentage in the monitored group had safe vitamin D levels (20–80 ng/mL) at 52 weeks of PCA (p = 0.017). We observed increased vitamin D levels and abnormal ultrasound findings in five infants. Biochemical markers of vitamin D toxicity were observed in two patients at 52 weeks of PCA in the control group. Inadequate and excessive amounts of vitamin D can lead to serious health problems. Supplementation with 800–1000 IU of vitamin D prevents deficiency and should be monitored to avoid overdose.     

High-Intensity Interval and Resistance Training Improve Health Outcomes in Older Adults With Coronary Disease

ObjectiveBoth high-intensity interval training (HIIT) and resistance exercises (R) are used in cardiac rehabilitation in patients with coronary artery disease (CAD). However, the combined effect of an HIIT + R exercise program in older adults with CAD is not well investigated. The study's purpose was to assess the changes in anthropometric parameters, physical activity, functional capacity, physiological parameters, and quality of life (QoL) in this population following a combined HIIT + R program.DesignThe study was a 2-group (n = 45 each) randomized controlled single-blinded trial.Setting and ParticipantsThe study was done at a treatment clinic of a tertiary hospital. The mean age of participants was 69.23 ± 4.9 years. The HIIT + R group performed 8 sessions (1/wk) of HIIT + R training. The 30 minutes of the active exercise phase consisted of ten 3-minute bouts. Each bout comprised of 1 minute of high-intensity treadmill walking at 85% to 90% maximum heart rate (MHR), followed by a low-intensity walking at 60%-70% MHR, followed by low-to moderate-intensity resistance training. The Usual Care group underwent conventional medical treatment.MeasuresAnthropometric measurements [weight, body mass index (BMI), waist circumference, body fat percentage, lean body mass], physical activity (International Physical Activity Questionnaire), functional capacity (Incremental Shuttle Walking Test), physiologic measurements (blood pressure, heart rate), and QoL (36-Item Short Form Health Survey) were measured pre- and postintervention.ResultsSignificant group and time interaction were found for the participants in the HIIT + R Group for BMI (P = .001), body fat percentage (P = .001), waist circumference (P < .001), physical activity (P < .001), functional capacity (P < .001), and QoL (P = .001) compared with the UC Group. Significant improvement in systolic blood pressure (P = .001) was seen in the HIIT + R group.Conclusions and ImplicationsA combined HIIT + R training protocol in older adults with CAD can be useful in producing desired health outcomes. Further evaluation of longer duration exercise programs with more frequent dosing needs to be evaluated for their benefits and sustainability.