Hypervitaminosis Notes

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Osmosis High-Yield Notes

This Osmosis High-Yield Note provides an overview of Hypervitaminosis essentials. All Osmosis Notes are clearly laid-out and contain striking images, tables, and diagrams to help visual learners understand complex topics quickly and efficiently. Find more information about Hypervitaminosis:

Excess Vitamin A

Excess Vitamin D

NOTES NOTES HYPERVITAMINOSIS GENERALLY, WHAT IS IT? PATHOLOGY & CAUSES ▪ Toxic effects due to increased ingestion/ storage of vitamins, most often fat soluble vitamins (vitamins A, D, E, K) ▫ Fat-soluble vitamins stored in fatty tissues, liver; remain in body for longer periods of time than water-soluble vitamins RISK FACTORS DIAGNOSIS ▪ See individual disorders TREATMENT OTHER INTERVENTIONS ▪ Discontinue consumption of vitamin supplements/food containing high levels of vitamins ▪ Increased ingestion of vitamin supplements/food containing high levels of vitamins EXCESS VITAMIN A osms.it/excess-vitamin-a PATHOLOGY & CAUSES ▪ Condition caused by excessive amounts of vitamin A in body ▪ Acute toxicity ▫ Occurs in adults when > 200,000mcg (> 660,000IU) consumed in single dose ▫ Occurs in infants < six months when > 6,000mcg (> 20,000IU) consumed < one month ▪ Chronic toxicity ▫ Long-term ingestion of high doses of vitamin A CAUSES ▪ Most likely by increased ingestion of synthetic “preformed” vitamin A, approximately 10 times the Recommended 274 OSMOSIS.ORG Dietary Allowance (RDA) ▫ Proforms of vitamin A (e.g. carotenoids) generally not toxic ▪ Teratogenic effects ▫ Effects on fetus during first trimester of pregnancy SIGNS & SYMPTOMS ▪ May compromise bone metabolism, health ▪ Acute toxicity ▫ Nausea, vomiting, blurry vision ▫ In extremely high doses: drowsiness, vomiting ▪ Chronic toxicity ▫ Ataxia, hair loss, bone/muscle pains, vision changes, liver damage, dry skin,
Chapter 46 Hypervitaminosis nausea, headache, hepatomegaly, increased risk of osteoporotic fractures ▪ Teratogenic effects ▫ Can cause spontaneous fetal death, facial/cardiac malformations (e.g. microcephaly) DIAGNOSIS DIAGNOSTIC IMAGING Bone X-rays ▪ Weakness/damage ▪ Liver function tests (LFTs): mild elevation of liver enzymes ▫ Liver biopsy: enlarged hepatocytes, increased fibrosis in chronic hypervitaminosis A TREATMENT OTHER INTERVENTIONS ▪ Discontinue consumption of vitamin A supplements/foods containing high levels of vitamin A, esp. containing natural vitamin A (e.g. kidney, liver, egg yolks) LAB RESULTS ▪ Most vitamin A stored in liver, circulating concentrations not always accurate indicator EXCESS VITAMIN D osms.it/excess-vitamin-d PATHOLOGY & CAUSES ▪ Toxicity caused by excessive amounts of vitamin D ▫ Vitamin D increases circulating levels of calcium ▫ Most often caused by excessive intake ▪ Maximum tolerable intake 100mg for children > nine years old, adults, pregnant/ lactating individuals; lower for younger children ▪ Main consequence is hypercalcemia SIGNS & SYMPTOMS ▪ Acute intoxication (often due to hypercalcemia) ▫ Confusion, excessive thirst, nausea, vomiting ▪ Chronic intoxication ▫ Bone demineralization, pain; nephrocalcinosis; kidney damage DIAGNOSIS LAB RESULTS ▪ Serum concentration of 25(OH)D > 150ng/ mL (374nmol/L) TREATMENT OTHER INTERVENTIONS ▪ Discontinue consumption of vitamin D supplements; restrict dietary intake of calcium, dairy products (milk, cheese, yogurt), almonds OSMOSIS.ORG 275

Osmosis High-Yield Notes

This Osmosis High-Yield Note provides an overview of Hypervitaminosis essentials. All Osmosis Notes are clearly laid-out and contain striking images, tables, and diagrams to help visual learners understand complex topics quickly and efficiently. Find more information about Hypervitaminosis by visiting the associated Learn Page.