Vitamin D therapy: problems and prospects

1975 ◽  
Vol 13 (8) ◽  
pp. 29-31

Natural vitamin D (D3, cholecalciferol) reaches the body from animal sources in the diet and from endogenous skin synthesis by the action of solar ultraviolet irradiation. Vitamin D2 (ergocalciferol) is used for fortifying proprietary foods such as margarine (and milk in the USA and Canada). These compounds have equal potency in man. A regular intake of 2.5 micrograms (100 i.u.) daily for adults and about 10 micrograms (400 i.u.) daily for children under 5 years old is usually recommended to prevent nutritional osteomalacia and rickets.

2021 ◽  
Vol 17 (5) ◽  
pp. 435-442
Author(s):  
O.V. Kaminsky

Despite its historical name, vitamin D is not a vitamin at all but a hormone that, when activated, is a metabolically active steroid fat-soluble hormone that acts on cellular receptors. Vitamin D hormone is synthesized endogenously and then metabolized in the body, provi-ding that there are the necessary precursors and some factors — the effects of ultraviolet light on the skin. At the same time, vitamins themselves are nutrients, co-factors of biochemical reactions that are not synthesized in the body and cannot interact with receptors, consumed with food, so the hormone D is not a vitamin. Disputes about its use and dosage continue throughout the study period of vitamin D hormone. Most reputable experts in Europe and the USA support the need to replenish and maintain a normal level of vitamin D, believing it to be completely safe and useful. In 2011, the US Endocrine Society issued clinical practice guidelines for vitamin D, indicating that the desired serum concentration of 25(OH)D is > 75 nmol/l (> 30 ng/ml) to achieve the maximum effect of this vitamin on calcium metabolism, bone, and muscle metabolism. According to them, for a consistent increase in serum 25(OH)D above 75 nmol/l (30 ng/ml), adults may require at least 1,500-2,000 IU/day of additional vitamin D, at least 1,000 IU/day in children and adolescents. The most common form of thyroid dysfunction is secondary hyperparathyroidism, which develops due to vitamin D defect/deficiency (80–90 %). Non-optimal serum concentrations of 25(OH)D lead to secondary hyperparathyroidism, potentially leading to decreased bone mineralization and, ultimately, to an increased risk of osteopenia, osteoporosis and fractures, cardiac arrhythmia, and increased blood pressure. Vitamin D is most commonly used at a star-ting dose of 5,000 IU daily for 2–3 months, then transferring patients to maintenance doses of 2,000–4,000 IU/day daily that are consi-dered safe. However, it should be noted that some patients will need constant administration of 5,000 IU of vitamin D per day for a long time (years) to maintain the target optimal level of 25(OH)D in the blood, especially in patients with normocalcemic forms of secondary hyperparathyroidism.


2019 ◽  
Vol 9 (o3) ◽  
Author(s):  
Suaad Muhssen Ghazi ◽  
Fatin Shallal Farhan

Vitamin D deficiency is common in women with polycystic ovarian syndrome. Vitamin D plays an important physiologic role in reproductive functions of ovarian follicular development and luteinization through altering anti-müllerian hormone signaling, follicular stimulating hormone activity and progesterone production in human granulose cells. Vitamin D is precipitated in adipose fat tissues, making it notable to be used for the body as a result; obese people with high body mass index are already highly expected to have low levels of serum vitamin D.


Author(s):  
Stefan Bittmann

Since the outbreak near a fish market in Wuhan, China, in December 2019, researchers have been searching for an effective therapy to control the spreading of the new coronavirus SARS-CoV-2 and inhibit COVID-19 infection. Many countries like Italy, Spain, and the USA were ambushed by this viral agent. To date, more than 2.5 million people were infected with SARS-CoV-2. There is no clear answer, why SARS-CoV-2 infects so many people so fast. To date of April 2020, no effective drug has been found to treat this new severe viral infection. There are many therapy options under review and clinical trials were initiated to get clearer information, what kind of drug can help in this devastating and serious situation. The world has no time.


Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1408
Author(s):  
Hermann Brenner ◽  
Sabine Kuznia ◽  
Clarissa Laetsch ◽  
Tobias Niedermaier ◽  
Ben Schöttker

Meta-analyses of randomized controlled trials (RCTs) have demonstrated a protective effect of vitamin D3 (cholecalciferol) supplementation against cancer mortality. In the VITAL study, a RCT including 25,871 men ≥ 50 years and women ≥ 55 years, protective effects of vitamin D3 supplementation (2000 IU/day over a median of 5.3 years) with respect to incidence of any cancer and of advanced cancer (metastatic cancer or cancer death) were seen for normal-weight participants but not for overweight or obese participants. We aimed to explore potential reasons for this apparent variation of vitamin D effects by body mass index. We conducted complementary analyses of published data from the VITAL study on the association of body weight with cancer outcomes, stratified by vitamin D3 supplementation. Significantly increased risks of any cancer and of advanced cancer were seen among normal-weight participants compared to obese participants in the control group (relative risk (RR), 1.27; 95% confidence interval (CI), 1.07–1.52, and RR, 1.44; 95% CI, 1.04–1.97, respectively). No such patterns were seen in the intervention group. Among those with incident cancer, vitamin D3 supplementation was associated with a significantly reduced risk of advanced cancer (RR, 0.86; 95% CI, 0.74–0.99). The observed patterns point to pre-diagnostic weight loss of cancer patients and preventive effects of vitamin D3 supplementation from cancer progression as plausible explanations for the body mass index (BMI)—intervention interactions. Further research, including RCTs more comprehensively exploring the potential of adjuvant vitamin D therapy for cancer patients, should be pursued with priority.


Author(s):  
Maryam Mosavat ◽  
Aisling Smyth ◽  
Diana Arabiat ◽  
Lisa Whitehead

AbstractVitamin D contributes to numerous physiological processes within the body but primarily calcium and bone homeostasis. Emerging evidence highlights a novel role for vitamin D in maintaining and regulating optimal sleep. Sleep is a known regulator of bone health, highlighting the interconnectedness between vitamin D concentrations, sleep duration and bone metabolism. It is possible that the relationship between sleep length and vitamin D is bidirectional, with vitamin D playing a role in sleep health and conversely, sleep affecting vitamin D levels. Nevertheless, limited information on the direction of the interaction is available, and much remains to be learned concerning the complex relationship between insufficient sleep duration and vitamin D deficiency. Given the potential to implement interventions to improve sleep and vitamin D supplementation, understanding this relationship further could represent a novel way to support and improve health.


2021 ◽  
Vol 22 (10) ◽  
pp. 5251
Author(s):  
Ming-Yieh Peng ◽  
Wen-Chih Liu ◽  
Jing-Quan Zheng ◽  
Chien-Lin Lu ◽  
Yi-Chou Hou ◽  
...  

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is still an ongoing global health crisis. Immediately after the inhalation of SARS-CoV-2 viral particles, alveolar type II epithelial cells harbor and initiate local innate immunity. These particles can infect circulating macrophages, which then present the coronavirus antigens to T cells. Subsequently, the activation and differentiation of various types of T cells, as well as uncontrollable cytokine release (also known as cytokine storms), result in tissue destruction and amplification of the immune response. Vitamin D enhances the innate immunity required for combating COVID-19 by activating toll-like receptor 2. It also enhances antimicrobial peptide synthesis, such as through the promotion of the expression and secretion of cathelicidin and β-defensin; promotes autophagy through autophagosome formation; and increases the synthesis of lysosomal degradation enzymes within macrophages. Regarding adaptive immunity, vitamin D enhances CD4+ T cells, suppresses T helper 17 cells, and promotes the production of virus-specific antibodies by activating T cell-dependent B cells. Moreover, vitamin D attenuates the release of pro-inflammatory cytokines by CD4+ T cells through nuclear factor κB signaling, thereby inhibiting the development of a cytokine storm. SARS-CoV-2 enters cells after its spike proteins are bound to angiotensin-converting enzyme 2 (ACE2) receptors. Vitamin D increases the bioavailability and expression of ACE2, which may be responsible for trapping and inactivating the virus. Activation of the renin–angiotensin–aldosterone system (RAS) is responsible for tissue destruction, inflammation, and organ failure related to SARS-CoV-2. Vitamin D inhibits renin expression and serves as a negative RAS regulator. In conclusion, vitamin D defends the body against SARS-CoV-2 through a novel complex mechanism that operates through interactions between the activation of both innate and adaptive immunity, ACE2 expression, and inhibition of the RAS system. Multiple observation studies have shown that serum concentrations of 25 hydroxyvitamin D are inversely correlated with the incidence or severity of COVID-19. The evidence gathered thus far, generally meets Hill’s causality criteria in a biological system, although experimental verification is not sufficient. We speculated that adequate vitamin D supplementation may be essential for mitigating the progression and severity of COVID-19. Future studies are warranted to determine the dosage and effectiveness of vitamin D supplementation among different populations of individuals with COVID-19.


Author(s):  
Matthew F Warren ◽  
Kimberly A Livingston

Abstract The risk of vitamin D insufficiency in humans is a global problem that requires improving ways to increase vitamin D intake. Supplements are a primary means for increasing vitamin D intake, but without a clear consensus on what constitutes vitamin D sufficiency, there is toxicity risk with taking supplements. Chickens have been used in many vitamin D-related research studies, especially studies involving vitamin D supplementation. Our state-of-the-art review evaluates vitamin D metabolism and how the different hydroxylated forms are synthesized. We provide an overview with how vitamin D is absorbed, transported, excreted, and what tissues in the body store vitamin D metabolites. We also discuss a number of studies involving vitamin D supplementation with broilers and laying hens. Vitamin D deficiency and toxicity are also described and how they can be caused. The vitamin D receptor (VDR) is important for vitamin D metabolism. However, there is much more that can be understood with VDR in chickens. Potential research aims involving vitamin D and chickens should explore VDR mechanisms which could lead to newer insights with VDR. Utilizing chickens in future research to help with elucidating vitamin D mechanisms has great potential to advance human nutrition. Finding ways to increase vitamin D intake will be necessary because the coronavirus 2019 disease (COVID-19) pandemic is leading to increased risk of vitamin D deficiency in many populations. Chickens can provide a dual purpose with addressing pandemic-caused vitamin D deficiency: 1) vitamin D supplementation gives chickens added value with possibly leading to vitamin D-enriched meat and egg products; and 2) chickens’ use in research provides data for translational research. Expanding vitamin D-related research in chickens to include more nutritional aims in vitamin D status has great implications with developing better strategies to improve human health.


Author(s):  
Marius Baranauskas ◽  
Valerija Jablonskienė ◽  
Jonas Algis Abaravičius ◽  
Rimantas Stukas

There are about 466 million people with hearing impairments in the world. The scientific literature does not provide sufficient data on the actual nutrition and other variables of professional deaf athletes. The objectives of this study were to investigate and evaluate the body composition, the physical working capacity, the nutrition intake, and the blood parameters of iron and vitamin D in the Lithuanian high-performance deaf women’s basketball team players. The female athletes (n = 14) of the Lithuanian deaf basketball team aged 26.4 ± 4.5 years were recruited for an observational cross-sectional study. A 7-day food recall survey method was used to investigate their actual diet. The measurements of the body composition were performed using the BIA (bioelectrical impedance analysis) tetra-polar electrodes. In order to assess the cardiorespiratory and aerobic fitness levels of athletes, ergo-spirometry (on a cycle ergometer) was used to measure the peak oxygen uptake (VO2peak) and the physical working capacity at a heart rate of 170 beats per minute (PWC170). The athletes’ blood tests were taken to investigate the red blood cells, hemoglobin, 25-hydroxyvitamin D, ferritin, transferrin, iron concentrations, and total iron-binding capacity (TIBC). The consideration of the VO2peak (55.9 ± 6.1 mL/min/kg of body weight, 95% CI: 51.8, 58.9) and the low VO2peak (56–60 mL/min/kg of body weight) (p = 0.966) in the deaf women’s basketball team players revealed no differences. For the deaf female athletes, the PWC170 was equal to 20.3 ± 2.0 kgm/min/kg of body weight and represented only the average aerobic fitness level. The carbohydrate and protein intakes (5.0 ± 1.3 and 1.3 ± 0.3 g/kg of body weight, respectively) met only the minimum levels recommended for athletes. The fat content of the diet (38.1 ± 4.1% of energy intake) exceeded the maximum recommended content (35% of energy intake) (p = 0.012). The mean blood serum concentrations of 25(OH)D and ferritin (24.1 ± 6.6 nmol/L and 11.0 ± 4.1 µg/L, respectively) predicted vitamin D and iron deficits in athletes. Female athletes had an increased risk of vitamin D and iron deficiencies. Regardless of iron deficiency in the body, the better cardiorespiratory fitness of the deaf female athletes was essentially correlated with the higher skeletal muscle mass (in terms of size) (r = 0.61, p = 0.023), the lower percentage of body fat mass (r = −0.53, p = 0.049), and the reduced intake of fat (r = −0.57, p = 0.040).


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