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Solar Urticaria/Sun Allergy
Published in Charles Theisler, Adjuvant Medical Care, 2023
Vitamin D: Chronic spontaneous urticaria (CSU) is associated with low D3 concentrations and a higher prevalence of vitamin D deficiency. If the serum level of vitamin D was less than 30 ng/ml, subjects in one study were treated with a vitamin D2 supplement at a dose of 20,000 IU/day.2 After six weeks, these patients showed significant improvements compared with the non-vitamin D supplement group. This study revealed a significant association of lower serum vitamin D concentrations with CSU. Vitamin D supplements might improve symptoms and quality of life in CSU patients.2
The dietary requirements of infants
Published in Claire Tuck, Complementary Feeding, 2022
Vitamin D exists in two forms: (1) vitamin D3 or cholecalciferol, which is produced in the skin from 7-dehydrocholesterol by the action of sunlight, and (2) vitamin D2 (ergocalciferol), which is produced by some plants such as fungi and is less bioavailable than vitamin D3. The main factors affecting an infant’s vitamin D status are maternal vitamin D status during pregnancy and the infant’s exposure to ultraviolet radiation; ultraviolet exposure is often low.4The RNI for vitamin D is 8.5 μg per day for infants between 4 and 6 months and 7 μg per day for infants aged 7–12 months.4
Micronutrients
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
Sources of vitamin D in nature are limited. Fatty fishes such as salmon, tuna, mackerel, snapper, herring, roe, sardine, and cod liver oil are among the best sources. Small amounts of vitamin D are found in beef liver, cheese, milk, yogurt, and egg yolks. Vitamin D in these foods is primarily in the form of vitamin D3 and its metabolite 25-OH-D3. Fish have the highest natural vitamin D content because their main food are microalgae (67). Microalgae belonging to the plant kingdom contain cholesterol and some provitamin D3 sterols like sitosterol, desmosterol, fucosterol, and so on (67). In general, fruits and vegetables contain a small amount of vitamin D2 due to the contamination of plants with fungi (62–67). Some mushrooms and yeasts provide vitamin D2 in variable amounts. The vitamin D2 levels in mushrooms can be increased when they are exposed to sunlight or UV-B light, even after harvesting (3, 9, 33, 62–67).
Effectiveness of vitamin D2 supplementation on high-sensitivity C-reactive protein and other metabolic indices in menopausal Thai women: a randomized-controlled trial
Published in Gynecological Endocrinology, 2022
Suchada Indhavivadhana, Worawat Boonyachan, Manee Rattanachaiyanont, Thanyarat Wongwananuruk, Kitirat Techatraisak, Nutchaya Sa-nga-areekul
Different types of vitamin D (vitamin D2 and D3) seem to generate different outcomes. Vitamin D3 has a greater bioefficacy than vitamin D2 because vitamin D3 and its metabolites had a higher affinity for hepatic 25-hydroxylase, vitamin D binding protein (DBP), and vitamin D receptor (VDR). Moreover, 1,24,25-trihydroxyvitamin D3, the final metabolite of vitamin D3,also has tissue effects [20–22]. Previous publications reporting the effect of vitamin D on hsCRP focus mostly on vitamin D3, but our study provided additional information from vitamin D2. We are interested in vitamin D2 because of its wide margin of safety with low cost; we found that vitamin D2 might be effective at a similar magnitude as vitamin D3. Further studies in larger study populations using noninferiority randomized controlled trials are needed to confirm our findings.
Are the protective benefits of vitamin D in neurodegenerative disease dependent on route of administration? A systematic review
Published in Nutritional Neuroscience, 2020
Krystal Iacopetta, Lyndsey E. Collins-Praino, Femke T. A. Buisman-Pijlman, Jiajun Liu, Amanda D. Hutchinson, Mark R. Hutchinson
Vitamin D has two distinct forms, vitamin D3 or cholecalciferol and vitamin D2 or ergocalciferol, which are derived through distinct pathways.9 The major source of vitamin D for most people is vitamin D3, generated in the skin through conversion of 7-dehydrocholesterol from skin cell membranes mediated by ultraviolet (UV) light.10,11 However, changes in lifestyle and increased life expectancy have contributed to widespread vitamin D insufficiency due to a lack of adequate sun exposure, therefore increasing the use of synthetic vitamin D supplementation.12,13 Vitamin D3 can also be acquired in the diet from animal sources (e.g. meat, oily fish, egg yolk and liver) via absorption through the gastrointestinal tract.11,14 Conversely, Vitamin D2 is derived from fungi or yeast and can only be obtained exogenously through dietary intake.11,15 Few foods naturally have substantial quantities of vitamin D2; therefore, dietary vitamin D2 is primarily obtained through oral supplementation.16 Both vitamin D3 and D2 can be produced synthetically as supplements, with vitamin D2 remaining the major form of synthetic vitamin D produced commercially.17
The effect of vitamin D2 supplementation on muscle strength in early postmenopausal women: a randomized, double-blind, placebo-controlled trial
Published in Climacteric, 2018
C. Suebthawinkul, K. Panyakhamlerd, P. Yotnuengnit, A. Suwan, N. Chaiyasit, N. Taechakraichana
Regarding the vitamin D2 dosages used in this study, we referred to a recent study from the same institute. Woranitat and colleagues found that a vitamin D2 dose of 40 000 IU/week could increase 25(OH)D to sufficient levels in 86.4% of non-obese postmenopausal women40. The percentage of patients who achieved sufficient 25(OH)D levels in other studies was around 60–86.4%40,41. In Thailand, vitamin D2 (20 000 IU/capsule), a commercially available inactive vitamin D, is affordable by most of the population, costing less than 0.06 USD per 20 000 IU capsule. We decided to give 40 000 IU/week of vitamin D2 supplementation in order to assure sufficient 25(OH)D levels in most of the studied population while avoiding the level exceeding the upper limit of 50 ng/ml. In this study, 40 000 IU/week of vitamin D2 for 12 weeks significantly increased 25(OH)D levels to sufficient levels (>30 ng/ml) in 70.4% of the participants. There was only one case in this study where the 25(OH)D level was higher than 50 ng/ml.