VitaminsVitaminsDeficiencies & Deficiencies & ToxicitiesToxicities

VitaminsVitamins

Organic molecules needed in Organic molecules needed in small quantities for normal small quantities for normal metabolism and other metabolism and other biochemical functions, such as biochemical functions, such as growth or repair of tissuegrowth or repair of tissue

Attach to enzymes or coenzymes Attach to enzymes or coenzymes and help them activate anabolic and help them activate anabolic (tissue-building) processes(tissue-building) processes

VitaminsVitamins

Essential part of enzymatic Essential part of enzymatic reactionsreactions

Natural sources from both plants Natural sources from both plants and animalsand animals

Insufficient amounts result in Insufficient amounts result in various deficienciesvarious deficiencies

Vitamins (cont'd)Vitamins (cont'd)

Vitamin K and vitamin B complex Vitamin K and vitamin B complex vitamins obtained by synthesis in vitamins obtained by synthesis in the small intestinethe small intestine

Vitamin D can be synthesized by Vitamin D can be synthesized by the skin when exposed to sunlightthe skin when exposed to sunlight

Water-Soluble Water-Soluble VitaminsVitamins B-complex group and vitamin CB-complex group and vitamin C Can be dissolved in waterCan be dissolved in water Cannot be stored by the body in Cannot be stored by the body in

large amountslarge amounts Daily intake required to prevent Daily intake required to prevent

deficienciesdeficiencies

Fat-Soluble VitaminsFat-Soluble Vitamins

Vitamins A, D, E, KVitamins A, D, E, K Present in both plant and animal Present in both plant and animal

foodsfoods Stored in the liver and fatty Stored in the liver and fatty

tissuestissues Daily intake not requiredDaily intake not required

Fat-Soluble Vitamins Fat-Soluble Vitamins (cont'd)(cont'd) Deficiency occurs only after Deficiency occurs only after

prolonged deprivationprolonged deprivation Can become toxic if excessive Can become toxic if excessive

amounts are consumedamounts are consumed

Vitamins: Other IssuesVitamins: Other Issues

Nutrient mega dosingNutrient mega dosing Toxic hypervitaminosisToxic hypervitaminosis

Vitamin AVitamin A

Fat solubleFat soluble Vitamin A (retinol) derived from Vitamin A (retinol) derived from

animal fats (butter and milk), animal fats (butter and milk), eggs, meat, liver, fish liver oilseggs, meat, liver, fish liver oils

The vitamin A in animal tissues is The vitamin A in animal tissues is derived from carotenes, which are derived from carotenes, which are found in plants (green and yellow found in plants (green and yellow vegetables and yellow fruits)vegetables and yellow fruits)

Vitamin AVitamin A

Required for growth and Required for growth and development of bones and teethdevelopment of bones and teeth

Necessary for other processesNecessary for other processes– ReproductionReproduction– Integrity of mucosal and epithelial Integrity of mucosal and epithelial

surfacessurfaces– Cholesterol and steroid synthesisCholesterol and steroid synthesis– Essential for night visionEssential for night vision

Vitamin A: Deficiency Vitamin A: Deficiency statesstates

Hyperkeratosis of the skinHyperkeratosis of the skin Night blindnessNight blindness Skin conditionsSkin conditions

– Acne, psoriasis, keratosis follicularisAcne, psoriasis, keratosis follicularis

Vitamin A: ToxicityVitamin A: Toxicity

Ingestion of excessive amounts Ingestion of excessive amounts causes toxicity causes toxicity – Irritability, drowsiness, vertigo, Irritability, drowsiness, vertigo,

delirium, other symptomsdelirium, other symptoms– Increased intracranial pressure in Increased intracranial pressure in

infantsinfants– Generalized peeling of the skin and Generalized peeling of the skin and

erythema over several weekserythema over several weeks

DIAGNOSISDIAGNOSIS

Abnormalities of dark adaptation Abnormalities of dark adaptation are strongly suggestive of vitamin are strongly suggestive of vitamin deficiency .Serum level below the deficiency .Serum level below the normal range of 30-65mg/dl are normal range of 30-65mg/dl are commonly seen in advance commonly seen in advance deficiency.deficiency.

TREATMENTTREATMENT

Orally: DOSE 30,000 iu of vit A Orally: DOSE 30,000 iu of vit A daily for 1 week.daily for 1 week.

Advance deficiency with corneal Advance deficiency with corneal damage -20,000 ius/kg orally for damage -20,000 ius/kg orally for 5 days. 5 days.

Vitamin DVitamin D

Fat solubleFat soluble ““Sunshine vitamin”Sunshine vitamin” Responsible for proper utilization Responsible for proper utilization

of calcium and phosphorusof calcium and phosphorus Actually a group of analog steroid Actually a group of analog steroid

chemicalschemicals

Vitamin D (Fat Vitamin D (Fat Soluble)Soluble) Different chemicals, produce Different chemicals, produce

same effectsame effect Vitamin DVitamin D22 (ergocalciferol) (ergocalciferol)

– Plant vitamin DPlant vitamin D– Obtained through dietary sourcesObtained through dietary sources

Vitamin DVitamin D33 (cholecalciferol) (cholecalciferol)– Produced in the skin by ultraviolet Produced in the skin by ultraviolet

irradiation (sunshine)irradiation (sunshine)

Vitamin D (cont'd)Vitamin D (cont'd)

Vitamin DVitamin D22-containing foods-containing foods– Fish oils, salmon, sardines, herringFish oils, salmon, sardines, herring– Fortified milk, breads, cerealsFortified milk, breads, cereals– Animal livers, tuna fish, eggs, butterAnimal livers, tuna fish, eggs, butter

Endogenous synthesis in the skinEndogenous synthesis in the skin

Vitamin D: FunctionVitamin D: Function

Regulates absorption of and use Regulates absorption of and use of calcium and phosphorusof calcium and phosphorus

Necessary for normal calcification Necessary for normal calcification of bone and teethof bone and teeth

Vitamin D: IndicationsVitamin D: Indications

Dietary supplementDietary supplement Treatment of vitamin D deficiencyTreatment of vitamin D deficiency Treatment and correction of Treatment and correction of

conditions related to long-term conditions related to long-term deficiency: rickets, tetany, deficiency: rickets, tetany, osteomalaciaosteomalacia

Prevention of osteoporosisPrevention of osteoporosis

Vitamin D: Deficiency Vitamin D: Deficiency StatesStates

Vitamin DVitamin D deficiency generally results  deficiency generally results from an inadequate dietary intake of from an inadequate dietary intake of vitamin D, or too little exposure to vitamin D, or too little exposure to sunlight. sunlight.

The vitamin D deficiency has also been The vitamin D deficiency has also been found to occur in overcrowded urban found to occur in overcrowded urban areas.areas.

The absence of sunlight or smog The absence of sunlight or smog limitations inhibit the absorption of the D limitations inhibit the absorption of the D vitamin. vitamin.

Vitamin D: ToxicityVitamin D: Toxicity

Long-term ingestion of excessive Long-term ingestion of excessive amounts causes toxicity amounts causes toxicity – Hypertension, weakness, fatigue, Hypertension, weakness, fatigue,

headache, many othersheadache, many others– GI tract effectsGI tract effects– CNS effectsCNS effects

Forms of Vitamin DForms of Vitamin D

calcifediol calcifediol calcitriolcalcitriol dihydrotachysteroldihydrotachysterol ergocalciferolergocalciferol

DIAGNOSISDIAGNOSIS

Serum 25(OH)D and PTH level.Serum 25(OH)D and PTH level. Alkaline phosphatase level Alkaline phosphatase level

elevated.elevated. Serum calcium and phosphate low.Serum calcium and phosphate low. TreatmentTreatment 250-1000microgram daily for 3-4 250-1000microgram daily for 3-4

month, than decrease the dose 10-month, than decrease the dose 10-20 microgram or stop the therapy.20 microgram or stop the therapy.

Vitamin EVitamin E

Fat solubleFat soluble TocopherolsTocopherols Dietary plant sourcesDietary plant sources

– Fruits, grains, cereals, vegetables, Fruits, grains, cereals, vegetables, oils, wheat germoils, wheat germ

Animal sourcesAnimal sources– Eggs, chicken, meats, fishEggs, chicken, meats, fish

Vitamin E: FunctionVitamin E: Function

Exact biologic function of vitamin Exact biologic function of vitamin E is unknownE is unknown

Believed to act as an antioxidantBelieved to act as an antioxidant

Vitamin E: DeficienciesVitamin E: Deficiencies

The Vitamin E deficiency is commonly The Vitamin E deficiency is commonly found in infants and usually results found in infants and usually results from them having consumed formulas from them having consumed formulas high in polyunsaturated fatty acids that high in polyunsaturated fatty acids that are fortified with iron but not vitamin E. are fortified with iron but not vitamin E.

Also, because vitamin E is a fat-soluble Also, because vitamin E is a fat-soluble vitamin, a deficiency also develops in vitamin, a deficiency also develops in conditions associated with fat conditions associated with fat malabsorption, such as cystic fibrosis.  malabsorption, such as cystic fibrosis. 

Vitamin E: IndicationsVitamin E: Indications

Dietary supplementDietary supplement AntioxidantAntioxidant Treatment of deficiencyTreatment of deficiency

– Highest risk of deficiency in Highest risk of deficiency in premature infantspremature infants

DiagnosisDiagnosis

Plasma vitamin E levels can be Plasma vitamin E levels can be measured; normal levels are 0.5–measured; normal levels are 0.5–0.7 mg/dL or higher. Since 0.7 mg/dL or higher. Since vitamin E is normally transported vitamin E is normally transported in lipoproteins, the serum level in lipoproteins, the serum level should be interpreted in relation should be interpreted in relation to circulating lipids.to circulating lipids.

TreatmentTreatment

The potential antioxidant benefits of The potential antioxidant benefits of vitamin E can be achieved with vitamin E can be achieved with supplements of 100–400 IU/d. supplements of 100–400 IU/d.

Vitamin KVitamin K

Fat solubleFat soluble Three types: KThree types: K11, K, K22, K, K33

Dietary sources of KDietary sources of K11

– Green leafy vegetables (cabbage, Green leafy vegetables (cabbage, spinach), meats, milkspinach), meats, milk

Vitamin KVitamin K22 synthesized by synthesized by intestinal flora intestinal flora

Vitamin K: FunctionsVitamin K: Functions

Essential for synthesis of blood Essential for synthesis of blood coagulation factors in the livercoagulation factors in the liver

Vitamin K–dependent clotting Vitamin K–dependent clotting factorsfactors– IIII– VIIVII– IXIX– XX

Vitamin K: IndicationsVitamin K: Indications

Dietary supplementationDietary supplementation Treatment of deficiency states Treatment of deficiency states

(rare)(rare)– Antibiotic therapyAntibiotic therapy– Newborn infantsNewborn infants– Malabsorption Malabsorption

Reverse the effects of certain Reverse the effects of certain anticoagulants (warfarin)anticoagulants (warfarin)

Vitamin K: DeficienciesVitamin K: Deficiencies

The Vitamin K deficiency is commonly found among The Vitamin K deficiency is commonly found among newborns within the first few days postpartum. Poor newborns within the first few days postpartum. Poor placental transfer of vitamin K to the infant and also placental transfer of vitamin K to the infant and also inadequate production of vitamin K-producing inadequate production of vitamin K-producing intestinal flora is the main culprit. intestinal flora is the main culprit.

The deficiency can also be caused by a prolonged use The deficiency can also be caused by a prolonged use of drugs, such as antibiotics that destroy normal of drugs, such as antibiotics that destroy normal intestinal bacteria. intestinal bacteria. 

Additionally, other causes are a decreased bile flow to Additionally, other causes are a decreased bile flow to the small intestine from bile duct obstruction, a the small intestine from bile duct obstruction, a malabsorption of vitamin K due to bowel resection, malabsorption of vitamin K due to bowel resection, ulcerative colitis, or chronic hepatic disease. ulcerative colitis, or chronic hepatic disease.

The vitamin K deficiency seldom results from an The vitamin K deficiency seldom results from an insufficient dietary intake of it.insufficient dietary intake of it.

Laboratory FindingsLaboratory Findings

The prothrombin time (PT) is The prothrombin time (PT) is prolonged to a greater extent prolonged to a greater extent than the PTT, and with mild than the PTT, and with mild vitamin K deficiency only the PT is vitamin K deficiency only the PT is defective. Fibrinogen level, defective. Fibrinogen level, thrombin time, and platelet count thrombin time, and platelet count are not affected.are not affected.

TreatmentTreatment

Vitamin K deficiency responds Vitamin K deficiency responds rapidly to subcutaneous vitamin rapidly to subcutaneous vitamin K, and a single dose of 15 mg will K, and a single dose of 15 mg will completely correct laboratory completely correct laboratory abnormalities in 12–24 hours.abnormalities in 12–24 hours.

Water-Soluble Water-Soluble VitaminsVitamins Vitamin B complexVitamin B complex

– thiamine (Bthiamine (B11)) – pyridoxine (B– pyridoxine (B66))

– riboflavin (Briboflavin (B22)) – folic acid (B– folic acid (B99))

– niacin (Bniacin (B33)) – cyanocobalamin (B– cyanocobalamin (B1212))

– pantothenic acid (Bpantothenic acid (B55))

Vitamin CVitamin C– ascorbic acidascorbic acid

Water-Soluble Water-Soluble Vitamins (cont'd)Vitamins (cont'd) Can dissolve in waterCan dissolve in water Excessive amounts excreted in Excessive amounts excreted in

the urine, not stored in the bodythe urine, not stored in the body Toxic reactions are very rareToxic reactions are very rare

Vitamin BVitamin B11 (Thiamine) (Thiamine)

Water solubleWater soluble Food sourcesFood sources

– Whole grains, liver, beansWhole grains, liver, beans DeficienciesDeficiencies

– BeriberiBeriberi– Wernicke’s encephalopathyWernicke’s encephalopathy

Vitamin BVitamin B11 (Thiamine) (Thiamine) DeficienciesDeficiencies BeriberiBeriberi

– Brain lesions, polyneuropathy of Brain lesions, polyneuropathy of peripheral nerves, serous effusions, peripheral nerves, serous effusions, cardiac anatomic changescardiac anatomic changes

Wernicke’s encephalopathyWernicke’s encephalopathy– Cerebral beriberiCerebral beriberi

Vitamin BVitamin B11 (Thiamine): (Thiamine):Causes of DeficienciesCauses of Deficiencies Poor dietPoor diet Extended feverExtended fever HyperthyroidismHyperthyroidism Liver diseaseLiver disease AlcoholismAlcoholism MalabsorptionMalabsorption Pregnancy and breast-feedingPregnancy and breast-feeding

Vitamin BVitamin B11 (Thiamine) (Thiamine)FunctionsFunctions Essential for: Essential for:

– Carbohydrate metabolismCarbohydrate metabolism– Many metabolic pathways, including Many metabolic pathways, including

Krebs’ cycleKrebs’ cycle Maintains integrity of:Maintains integrity of:

– Peripheral nervous systemPeripheral nervous system– Cardiovascular systemCardiovascular system– GI tractGI tract

DiagnosisDiagnosis

Erythrocyte transketolase Erythrocyte transketolase activity. Coefficient greater than activity. Coefficient greater than 15-20% suggest thiamine 15-20% suggest thiamine deficiency. deficiency.

Urinary thiamine excretion.Urinary thiamine excretion.

Vitamin BVitamin B11 (Thiamine): (Thiamine):IndicationsIndications Treatment of thiamine deficiencyTreatment of thiamine deficiency

– BeriberiBeriberi– Wernicke’s encephalopathyWernicke’s encephalopathy– Peripheral neuritis associated with Peripheral neuritis associated with

pellagra pellagra Metabolic disordersMetabolic disorders

Vitamin BVitamin B11 (Thiamine): (Thiamine):Indications (cont'd)Indications (cont'd) Dietary supplementDietary supplement

– Malabsorption induced by Malabsorption induced by alcoholism, cirrhosis, GI diseasealcoholism, cirrhosis, GI disease

Thiamine deficiency is treated Thiamine deficiency is treated with large parental doses of with large parental doses of thiamine .50-100mg/d .All thiamine .50-100mg/d .All patients should simultaneously patients should simultaneously receive therapeutic doses of other receive therapeutic doses of other water soluble vitamins water soluble vitamins Other usesOther uses

Vitamin BVitamin B22 (Riboflavin) (Riboflavin)

Water solubleWater soluble Food sourcesFood sources

– Leafy green vegetablesLeafy green vegetables– EggsEggs– NutsNuts– MeatsMeats– YeastYeast

Vitamin BVitamin B22 (Riboflavin) (Riboflavin)Causes of DeficiencyCauses of Deficiency Alcoholism is a major causeAlcoholism is a major cause Deficiency also caused by: Deficiency also caused by:

– Intestinal malabsorptionIntestinal malabsorption– Long-term infectionsLong-term infections– Liver diseaseLiver disease– MalignancyMalignancy– Probenecid therapyProbenecid therapy

Vitamin BVitamin B22 (Riboflavin) (Riboflavin)FunctionsFunctions Converted into enzymes essential Converted into enzymes essential

for tissue respirationfor tissue respiration Required to activate vitamin BRequired to activate vitamin B66

(pyridoxine)(pyridoxine) Converts tryptophan into niacinConverts tryptophan into niacin Maintains erythrocyte integrity Maintains erythrocyte integrity

Vitamin BVitamin B22 (Riboflavin) (Riboflavin)DeficiencyDeficiency Deficiency results in:Deficiency results in:

– Cutaneous, oral, and corneal Cutaneous, oral, and corneal changeschanges

– CheilosisCheilosis– Seborrheic dermatitisSeborrheic dermatitis– KeratitisKeratitis

Vitamin BVitamin B22 (Riboflavin):(Riboflavin):IndicationsIndications Dietary supplementDietary supplement Treatment of deficiency Treatment of deficiency Microcytic anemiaMicrocytic anemia AcneAcne Migraine headachesMigraine headaches Many other usesMany other uses

Vitamin BVitamin B22 (Riboflavin):(Riboflavin):Side EffectsSide Effects No side effects or toxic effectsNo side effects or toxic effects Large doses will discolor urine to Large doses will discolor urine to

a yellow-orangea yellow-orange

Vitamin BVitamin B33 (Niacin) (Niacin)

Water solubleWater soluble Food sourcesFood sources

– Meats, beans, liver, yeast, wheatMeats, beans, liver, yeast, wheat Also synthesized from tryptophan Also synthesized from tryptophan

(an essential amino acid obtained (an essential amino acid obtained from protein digestion) from protein digestion)

Vitamin BVitamin B33 (Niacin): (Niacin):FunctionsFunctions Once ingested, converted to Once ingested, converted to

nicotinamidenicotinamide Nicotinamide is converted to two Nicotinamide is converted to two

coenzymescoenzymes These enzymes are required for:These enzymes are required for:

– Glycogenolysis, tissue respirationGlycogenolysis, tissue respiration– Lipid, protein, and purine Lipid, protein, and purine

metabolismmetabolism

Vitamin BVitamin B33 (Niacin): (Niacin):IndicationsIndications Antihyperlipidemic agentAntihyperlipidemic agent

– Lowers serum cholesterol and Lowers serum cholesterol and triglyceride levels by reducing VLDL triglyceride levels by reducing VLDL synthesissynthesis

– Doses required for this effect are Doses required for this effect are higher than those required for its higher than those required for its nutritional and metabolic effectsnutritional and metabolic effects

Vitamin BVitamin B33 (Niacin): (Niacin):DeficiencyDeficiency Pellagra: niacin deficiencyPellagra: niacin deficiency

– Mental: various psychotic symptomsMental: various psychotic symptoms– Neurologic: neurasthenic syndromeNeurologic: neurasthenic syndrome– Cutaneous: crusting, erythemaCutaneous: crusting, erythema– Mucous membrane: oral, vaginal, Mucous membrane: oral, vaginal,

and urethral lesionsand urethral lesions– GI: diarrhea or bloody diarrhea GI: diarrhea or bloody diarrhea

Vitamin BVitamin B33 (Niacin): (Niacin):Side EffectsSide Effects Side effects seen when higher Side effects seen when higher

doses are used in the treatment doses are used in the treatment of hyperlipidemiaof hyperlipidemia– FlushingFlushing– PruritusPruritus– GI distress GI distress

Vitamin BVitamin B66 (Pyridoxine) (Pyridoxine)

Water solubleWater soluble SourcesSources

– Whole grains, wheat germ, nuts, Whole grains, wheat germ, nuts, yeastyeast

– Fish and organ meatsFish and organ meats

Vitamin BVitamin B66 (Pyridoxine) (Pyridoxine) (cont'd)(cont'd) Composed of three compoundsComposed of three compounds

– PyridoxinePyridoxine– PyridoxalPyridoxal– PyridoxaminePyridoxamine

Vitamin BVitamin B66 (Pyridoxine):(Pyridoxine):FunctionFunction Necessary for many metabolic Necessary for many metabolic

functionsfunctions– Protein, lipid, and carbohydrate Protein, lipid, and carbohydrate

utilizationutilization– Conversion of tryptophan to niacinConversion of tryptophan to niacin

Necessary for integrity of Necessary for integrity of peripheral nerves, skin, mucous peripheral nerves, skin, mucous membranes, hematopoietic systemmembranes, hematopoietic system

Vitamin BVitamin B66 (Pyridoxine) (Pyridoxine) (cont'd)(cont'd) Signs and symptoms of deficiencySigns and symptoms of deficiency

– Sideroblastic anemiaSideroblastic anemia– Neurologic disturbancesNeurologic disturbances– Seborrheic dermatitisSeborrheic dermatitis– Cheilosis (chapped, fissured lips)Cheilosis (chapped, fissured lips)– Xanthurenic aciduria (“stones” in Xanthurenic aciduria (“stones” in

the urine)the urine)– Glossitis and stomatitisGlossitis and stomatitis– Epileptiform convulsionsEpileptiform convulsions

Vitamin BVitamin B66 (Pyridoxine):(Pyridoxine):Causes of DeficiencyCauses of Deficiency Inadequate intakeInadequate intake Poor absorptionPoor absorption Uremia, alcoholism, cirrhosis, Uremia, alcoholism, cirrhosis,

hyperthyroidism, malabsorption, hyperthyroidism, malabsorption, heart failureheart failure

Drug induced (isoniazid, Drug induced (isoniazid, hydralazine, others)hydralazine, others)

DIAGNOSISDIAGNOSIS

Blood pyridoxal Blood pyridoxal phosphate .Normal level phosphate .Normal level >50ng/ml.>50ng/ml.

TREATMENTTREATMENT VITAMIN B6 Dose-10 -20mg/day.VITAMIN B6 Dose-10 -20mg/day. TOXICITYTOXICITY Sensory neuropathy.Sensory neuropathy.

Vitamin BVitamin B66 (Pyridoxine) (Pyridoxine)ToxicityToxicity

Toxic effects occur with large Toxic effects occur with large doses, especially neurotoxicitydoses, especially neurotoxicity

Vitamin BVitamin B1212 (Cyanocobalamin)(Cyanocobalamin) Water solubleWater soluble Synthesized by microorganisms Synthesized by microorganisms

present in the bodypresent in the body Food sourcesFood sources

– Liver, kidney, fish, shellfish, meat, Liver, kidney, fish, shellfish, meat, dairy foodsdairy foods

Contained in minimal amounts in Contained in minimal amounts in plantsplants

General ConsiderationsGeneral Considerations

Vitamin B12 belongs to the family of Vitamin B12 belongs to the family of cobalamins and serves as a cofactor for cobalamins and serves as a cofactor for two important reactions in humans . As two important reactions in humans . As methylcobalamin, it is a cofactor for methylcobalamin, it is a cofactor for methionine synthetase in the conversion methionine synthetase in the conversion of homocysteine to methionine, and as of homocysteine to methionine, and as adenosylcobalamin for the conversion of adenosylcobalamin for the conversion of methylmalonyl-coenzyme A (CoA) to methylmalonyl-coenzyme A (CoA) to succinyl-CoA. All vitamin B12 comes from succinyl-CoA. All vitamin B12 comes from the diet and is present in all foods of the diet and is present in all foods of animal origin. The daily absorption of animal origin. The daily absorption of vitamin B12 is 5 mcg.vitamin B12 is 5 mcg.

Vitamin BVitamin B1212 (Cyanocobalamin): (Cyanocobalamin): FunctionFunction Required for many metabolic Required for many metabolic

pathwayspathways– Fat and carbohydrate metabolismFat and carbohydrate metabolism– Protein synthesisProtein synthesis– Growth, cell replicationGrowth, cell replication– HematopoiesisHematopoiesis– Nucleoprotein and myelin synthesisNucleoprotein and myelin synthesis

Vitamin BVitamin B1212 (Cyanocobalamin): (Cyanocobalamin): DeficiencyDeficiency Deficiency leads to:Deficiency leads to:

– Neurologic damageNeurologic damage– Pernicious anemiaPernicious anemia

Deficiency states caused by:Deficiency states caused by:– MalabsorptionMalabsorption– Poor dietary intake (vegetarians)Poor dietary intake (vegetarians)

Vitamin BVitamin B1212 (Cyanocobalamin): Oral (Cyanocobalamin): Oral AbsorptionAbsorption Oral absorption of vitamin BOral absorption of vitamin B1212

(extrinsic factor) required (extrinsic factor) required presence of the intrinsic factorpresence of the intrinsic factor

The intrinsic factor is a The intrinsic factor is a glycoprotein secreted from the glycoprotein secreted from the gastric parietal cellsgastric parietal cells

Vitamin BVitamin B1212 (Cyanocobalamin): Oral (Cyanocobalamin): Oral Absorption (cont'd)Absorption (cont'd)The extrinsic and intrinsic factors The extrinsic and intrinsic factors form a complex that is then form a complex that is then absorbed by the intestines absorbed by the intestines

TreatmentTreatment

Intramuscular injections of 100 mcg of vitamin B12 Intramuscular injections of 100 mcg of vitamin B12 are adequate for each dose. Replacement is usually are adequate for each dose. Replacement is usually given daily for the first week, weekly for the first given daily for the first week, weekly for the first month, and then monthly for life. It is a lifelong month, and then monthly for life. It is a lifelong disorder, and if patients discontinue their monthly disorder, and if patients discontinue their monthly therapy the vitamin deficiency will recur. Oral therapy the vitamin deficiency will recur. Oral cobalamin The dose is 1000 mcg/d and must be cobalamin The dose is 1000 mcg/d and must be continued indefinitely.continued indefinitely.

Patients respond to therapy with an immediate Patients respond to therapy with an immediate improvement in their sense of well-being. A brisk improvement in their sense of well-being. A brisk reticulocytosis occurs in 5–7 days, and the reticulocytosis occurs in 5–7 days, and the hematologic picture normalizes in 2 months. Central hematologic picture normalizes in 2 months. Central nervous system symptoms and signs are reversible nervous system symptoms and signs are reversible if they are of relatively short duration (less than 6 if they are of relatively short duration (less than 6 months) but become permanent if treatment is not months) but become permanent if treatment is not initiated promptly.initiated promptly.

Vitamin C (Ascorbic Vitamin C (Ascorbic Acid)Acid) Water solubleWater soluble Natural sourcesNatural sources

– Citrus fruits and juicesCitrus fruits and juices– TomatoesTomatoes– CabbageCabbage– CherriesCherries– Liver Liver

Can also be synthesizedCan also be synthesized

Vitamin C (Ascorbic Vitamin C (Ascorbic Acid):Acid):FunctionsFunctions Acts in oxidation-reduction reactionsActs in oxidation-reduction reactions Required for several metabolic Required for several metabolic

activitiesactivities– Collagen synthesisCollagen synthesis– Maintenance of connective tissueMaintenance of connective tissue– Tissue repairTissue repair– Maintenance of bone, teeth, and Maintenance of bone, teeth, and

capillariescapillaries– Folic acid metabolism Folic acid metabolism – ErythropoiesisErythropoiesis

Vitamin C (Ascorbic Vitamin C (Ascorbic Acid):Acid):Functions (cont'd)Functions (cont'd) Enhances absorption of ironEnhances absorption of iron Required for the synthesis of:Required for the synthesis of:

– LipidsLipids– ProteinsProteins– SteroidsSteroids

Aids in cellular respirationAids in cellular respiration Aids in resistance to infectionsAids in resistance to infections

Vitamin C (Ascorbic Vitamin C (Ascorbic Acid):Acid):DeficiencyDeficiency Prolonged deficiency results in Prolonged deficiency results in

scurvyscurvy– Gingivitis and bleeding gumsGingivitis and bleeding gums– Loss of teethLoss of teeth– AnemiaAnemia– Subcutaneous hemorrhageSubcutaneous hemorrhage– Bone lesionsBone lesions– Delayed healing of soft tissues and Delayed healing of soft tissues and

bonesbones

DIAGNOSISDIAGNOSIS

Diagnose on clinical ground.Diagnose on clinical ground. Ascorbic acid level below Ascorbic acid level below

0.1mg/dl.0.1mg/dl.

TREATMENTTREATMENT

300-1000mg/d of ascorbic acid. Response 300-1000mg/d of ascorbic acid. Response occurs within days.occurs within days.

High intake decrease the risk of cancer, also High intake decrease the risk of cancer, also protect from against coronary heart disease.protect from against coronary heart disease.

TOXICITYTOXICITY High doses cause gastric High doses cause gastric

irritation,flatulence,or diarrhea.it may also irritation,flatulence,or diarrhea.it may also causes false negative test for faecal occult causes false negative test for faecal occult blood and false positive and false negative blood and false positive and false negative test for urine glucose. test for urine glucose.

Vitamin C (Ascorbic Vitamin C (Ascorbic Acid):Acid):MegadosesMegadoses Megadoses may cause:Megadoses may cause:

– Nausea, vomiting, headache, Nausea, vomiting, headache, abdominal crampsabdominal cramps

– Acidified urine, with possible stone Acidified urine, with possible stone formationformation

Discontinuing megadoses may Discontinuing megadoses may result in scurvy-like symptomsresult in scurvy-like symptoms