Orthopaedic Pharmacology
Manoj Ramachandran, Tom Nunn in Basic Orthopaedic Sciences, 2018
Ergocalciferol (vitamin D2) – used in vitamin D deficiency (rickets, osteomalacia).Cholecalciferol (vitamin D3) – used in vitamin D deficiency and osteoporosis.Calcitriol (1,25-OH-vitamin D3) – used in renal osteodystrophy.Alphacalcidiol (1α-hydroxycholecalciferol) – used in renal osteodystrophy.
Antenatal care
Louise C Kenny, Jenny E Myers in Obstetrics, 2017
The RCOG advises that there are no data to support routine screening for vitamin D deficiency in pregnancy in terms of health benefits or cost effectiveness. Women thought to be at increased risk of vitamin D deficiency on the basis of skin colour or coverage, obesity, risk of pre-eclampsia or gastroenterological conditions limiting fat absorption may be screened, but this testing is expensive. Daily vitamin D supplementation with oral cholecalciferol or ergocalciferol is safe in pregnancy. NICE guidance states that all pregnant and breastfeeding women should be advised to take 10 μg of vitamin D supplements daily. Severe vitamin D deficiency in pregnancy results in increased risk of neonatal rickets.
Annexes
Claude Leray in Dietary Lipids for Healthy Brain Function, 2017
UV irradiation of ergosterol, contained in vegetable oils and fungi, produces ergocalciferol (vitamin D2). Its biological activities with respect to vitamin D3 have not yet been precisely determined; for some they are three times lower, whereas for the others the two forms are equivalent. Ergocalciferol is poorly represented in the diet, but it is often provided by pharmaceutical preparations used as vitamin D supplement.
When and How to Diagnose and Treat Vitamin D Deficiency in Adults: A Practical and Clinical Update
Published in Journal of Dietary Supplements, 2020
Antoine Aoun, Jessica Maalouf, Myriam Fahed, Flora El Jabbour
Vitamin D, identified in 1921, consists of two bioequivalent forms. Vitamin D2 (D2), also known as ergocalciferol, is obtained mainly from fungi, yeast, and oral supplements. Vitamin D3 (D3), also known as cholecalciferol, is obtained primarily from skin exposure to ultraviolet B (UVB) radiation in sunlight, ingestion of food sources such as oily fish and variably fortified foods (milk, juices, margarines, yogurts, cereals, and soy), and oral supplements. Aside from rich sources such as oily fish, the vitamin D content of most foods is between 50 and 200 IU per serving. The intake of vitamin D from food sources varies greatly worldwide with the variability of food fortification. Once absorbed from the intestine, D2 and D3 are metabolized in the liver to 25-hydroxyvitamin D [25(OH)D], composed of 25(OH)D2 and 25(OH)D3; 25(OH)D (also called calcidiol) is subsequently converted to 1,25-dihydroxyvitamin D [1,25(OH)2D], called calcitriol, in the kidney and some other organs by the action of the 1-hydroxylase enzyme. The predominant effects of vitamin D are exerted through the endocrine and autocrine actions of calcitriol via activation of the vitamin D receptor in cells (Kennel et al. 2010; DeLuca 2016; Sempos et al. 2018; Hossain et al. 2018).
Vitamin D intakes and health outcomes in infants and preschool children: Summary of an evidence report
Published in Annals of Medicine, 2022
Andrew R. Beauchesne, Kelly Copeland Cara, Danielle M. Krobath, Laura Paige Penkert, Shruti P. Shertukde, Danielle S. Cahoon, Belen Prado, Ruogu Li, Qisi Yao, Jing Huang, Tee Reh, Mei Chung
Vitamin D is a conditionally essential micronutrient because the amount synthesised in the skin under sunlight (ultraviolet [UV]-B light) exposure is often not sufficient to meet our needs, and thus humans need to consume dietary forms of vitamin D under certain circumstances. Vitamin D content in human milk is highly variable and might be affected by season, maternal dietary intake of vitamin D, and ethnicity [105], and there is little vitamin D that occurs naturally in the food supply. The efficacy of conversion of 7-dehydrocholesterol in the skin after exposure to UV-B light to cholecalciferol (vitamin D3) is dependent on the time of day, the season of the year, latitude, skin colour, and age. Vitamin D2 (ergocalciferol) is produced in mushrooms and yeast. The native form of vitamin D is not biologically active. The active form of vitamin D is 1,25(OH)2D (calcitriol), which is first hydroxylated from vitamin D to 25(OH)D in the liver and then hydroxylated by the kidney. One of the major biological functions of vitamin D is to maintain calcium homeostasis. Calcitriol also acts as a hormone working through the activation of signal transduction pathways linked to vitamin D receptors on cell membranes. Major sites of action include the intestine, bone, parathyroid, liver, and pancreatic beta cells. Thus, vitamin D could be considered a prohormone that can affect the risks of disease development.
Health implication of vitamin D on the cardiovascular and the renal system
Published in Archives of Physiology and Biochemistry, 2021
Raghad Khalid Al-Ishaq, Peter Kubatka, Martina Brozmanova, Katarina Gazdikova, Martin Caprnda, Dietrich Büsselberg
A normal blood vitamin-D-level is between 30 ng/ml and 150 ng/ml (Dawson-Hughes 2004). To determine the vitamin-D status of an individual, the inactive circulating form of vitamin D(25(OH)D) (synthesised in the liver) is measured. Vitamin D, a fat-soluble vitamin, acts as a steroid hormone-regulating body functions. It exists in two forms: D3 (cholecalciferol) and D2 (ergocalciferol) (Lutsey and Michos 2013). While vitamin D3 is synthesised through sun exposure of the skin or by digesting oily fish (such as salmon and sardines), vitamin D2 is obtained by consuming plants that produces vitamin D as a product of an ergosterol irradiation process (Bikle 2014). It regulates intracellular calcium and phosphorus and, therefore, influences metabolic activities such as oxidative stress, cell adhesion (important for immunological responses), cellular proliferation and apoptosis (DeLuca 2004). Vitamin D deficiency leads to multiple metabolic disorders, while its excess leads to complications such as renal impairment, malignancy, and manifestation of cardiovascular diseases (Souberbielle et al.2003, Lee et al.2008).
Related Knowledge Centers
- Dietary Supplement
- Hypocalcemia
- Intramuscular Injection
- Liver Disease
- Malabsorption
- Vitamin D Deficiency
- Hypertension
- Vitamin D
- Hypoparathyroidism
- Kidney Stone Disease