Vitamin D toxicity

Toxicity. Vitamin D toxicity was known as eady as the year 1429 (217). Accidental toxicity has been reported in monkeys, dogs, horses, pigs, chinchillas, and humans, and particulady in catde when extremely high doses of vitamin D have been used to treat milk fever. 

Vitamin D toxicity has been suggested as a cause of metabolic bone disease. However, vitamin D deficiency results in bone loss, and data on vitamin D excess and metabolic bone disease remain controversial. 

Excess vitamin D can result in hypervitaminosis D with serious vitamin D toxicity characterized by hypercalcemia and nephrocalcinosis. 

Hypercalcemia is a common clinical condition that can accompany a variety of other medical conditions, such as sarcoidosis, vitamin D toxicity, hyperparathyroidism, and malignancy. When calcium levels are exceptionally high, adjunctive measures for the control of plasma calcium levels are necessary, as this is a medical emergency. Various modalities in combination are used to treat this condition intravenous hydration with normal saline and the use of loop diuretics (e.g., furosemide) to induce calcium diuresis are the most important supportive measures. 

Contraindications Hypercalcemia or evidence of vitamin D toxicity, use on face, hypersensitivity to calcipotriene or any component of the formulation... 

Contraindications Hypercalcemia, malabsorption syndrome, vitamin D toxicity, hypersensitivity to other vitamin D products or analogs... 

Vitamin D is a fat-soluble vitamin, and excessive doses can accumulate in the body, leading to toxicity. Some early signs of vitamin D toxicity include headache, increased thirst, decreased appetite, metallic taste, fatigue, and gastrointestinal disturbances (nausea, vomiting, constipation, or diarrhea). Increased vitamin D toxicity is associated with hypercalcemia, high blood pressure, cardiac arrhythmias, renal failure, mood changes, and seizures. Vitamin D toxicity is a serious problem that can cause death because of cardiac and renal failure. 

Excessive intake of vitamin D Toxic effect of vitamin D, as opposed to vitamin D3... 

Blum M, Kirsten M, Worth MH Jr. Reversible hypertension. Caused by the hypercalcemia of hyperparathyroidism, vitamin D toxicity, and calcium infusion. JAMA 1977 237(3) 262-3. 

Evliyaoglu O, Berberoglu M, Ocal G, Adiyaman P, Aycan Z. Severe hypercalcemia of an infant due to vitamin D toxicity associated with hypercholesterolemia. J Pediatr Endocrinol Metab 2001 14(7) 915-19. 

Misselwitz J, Hesse V, Markestad T. Nephrocalcinosis, hypercalciuria and elevated serum levels of 1,25-dihydroxy-vitamin D in children. Possible link to vitamin D toxicity. Acta Paediatr Scand 1990 79(6-7) 637-43. 

Schwartzman MS, Franck WA. Vitamin D toxicity complicating the treatment of senile, postmenopausal, and glucocorticoid-induced osteoporosis. Four case reports and a critical commentary on the use of vitamin D in these disorders. Am J Med 1987 82(2) 224-30. 

Pettifor JM, Bikle DD, Cavaleros M, Zachen D, Kamdar MC, Ross FP. Serum levels of free 1,25-dihydroxy-vitamin D in vitamin D toxicity. Ann Intern Med 1995 122(7) 511-13. 

Contraindications Hypercalcemia or evidence or vitamin D toxicity or use on the face Caution History of nephrolithiasis... 

Vieth R. The mechanisms of vitamin D toxicity. Bone Miner 1990 11 267-72. 

Vitamin D Vitamin D is produced when ultraviolet light (UV) shines on the skin and triggers the conversion of a steroid known as ergosterol to vitamin D. Its major role is to help the body use calcium, and a deficiency causes rickets in children, the same condition caused by calcium deficiency. Vitamin D supplements are rarely needed, except by those who are almost never exposed to the sun. Both vitamin A and vitamin D are essential to normal growth and development. Overdosage of vitamin D can have serious consequences, however. Calcium deposits can form in the kidney, lungs, or tympanic membrane of the ear (leading to deafness). Infants and small children are especially susceptible to vitamin D toxicity. 

Carlton S, Clopton D, Cappuzzo KA. Vitamin D deficiency appropriate replenishment therapies and the effects of vitamin D toxicity. Consult Pharm 2010 25(3) 171-7. 

Lowe H, Cusano NE, Binkley N, Blaner WS, Bilezikian JP. Vitamin D toxicity due to a commonly available over the counter remedy from the Dominican... 

Dr. Pruitt from the Institute of Surgical Research at Brooke Army Medical Center has observed one adult patient who inadvertently received 30 ml of MVI (US Vitamins, multivitamin preparation for injection) intravenously for 2 weeks, which corresponded to approximately 3,000 International units per day of vitamin D. This patient developed a markedly elevated serum calcium concentration with multiple areas of tissue calcification secondary to vitamin D toxicity (Pruitt, Personal Communication). 

Vitamin D is a pro-hormone that comes in two forms, cholecalciferol (vitamin D3) and ergocalciferol (vitamin Dj) (Haddad and Hahn 1973). Most of vitamin D is obtained as vitamin D3, through synthesis in the skin after exposure to UVB radiation (typically from sunlight) of wavelengths 290-315 nm (Holick 1995). The synthesis converts 7-dehydrocholesterol (DHC-7) to pre-vitamin D3, which is then quickly converted by heat induction to vitamin D3. Overexposure to UVB radiation does not cause vitamin D toxicity as excess pre-vitamin D3 and vitamin D3 is inactivated by radiation (Holick et al. 1981, Webb et al. 1989). Vitamin D3 can also be obtained from animal-based food products, with oily fish (e.g., salmon, sardines, and mackerel) being the best natural source, and egg yolk and meat containing smaller quantities. Vitamin D2 is the plant form of vitamin D and can occur naturally in some types of mushrooms (Lamberg-Allardt 2006). 

Jones, G. 2008b. Pharmacokinetics of vitamin D toxicity. Am J Clin Nutr, 88 582S-586S. 

The effect of vitamin D supplementation on the frequency of vitamin D deficiency, respiratory outcomes and vitamin D toxicity in patients with cystic fibrosis has been assessed. No adverse events were reported [72 ]. 

The recommended treatment administration of vitamin D (1,000 lU daily) and calcium (1-2 g per day). Care should be taken that vitamin D toxicity does not develop during treatment. 

Recommended Daily Allowance of Vitamin D Toxicity (Hypervitaminosis D)... 

Within the control limits, increased intakes of vitamin D lead to increased blood levels of 25-OHD but not of l,25-(OH)2D and homeostasis is maintained. However, at higher dietary levels of vitamin D, toxic manifestations of hypercalcaemia become increasingly evident with deformation of bone and even calcification of soft tissues. Thus vitamin D is toxic at dietary levels which overload the control processes. 

Observations on 15 infants with vitamin D intoxication after high doses of vitamin D (1-25.2 Mio. units given over a period as short as one month and as long as 4 months (49 -) have been reported. The authors of this paper, from the Lebanon, stress once more the fact that, particularly in developing countries, cases of vitamin D toxicity in children continue to occur because of the public demand for parenteral vitamin treatment, despite the fact that paediatricians are well aware of the risks. 

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