All About Vitamins - Important Information and Diseases

Vitamin

Important information and RDA

Diseases caused

Thiamine - Vitamin B1

The Recommended Dietary Allowance for thiamine is 0.5 mg/1000 calories, depending on calorie or carbohydrate intake.

Neurons get affected- dry Beri-Beri. 

CNS is involved: wet Beri-Beri. 

Wernicke’s encephalopathy- Acute thiamine deficiency (Global Confusion, Ophthalmoplegia, and Ataxia, respectively.) 

Chronic thiamine deficiency- Korsakoff syndrome(amnesia, Confabulation (Fabrication of stories to fill the memory gaps), and Sensory agnosia.)

Riboflavin - Vitamin B2

For Vitamin B2 deficiency - RBC or erythrocyte glutathione reductase activity should be checked.

Angular Stomatitis

The 1st sign of riboflavin deficiency is Circumcorneal congestion.

Niacin or B3

The precursor of niacin is tryptophan. 60 mg of tryptophan = 1 mg of niacin.

Niacin deficiency causes Pellagra (Characterized by 3 D's: Diarrhea, Dementia, and Dermatitis (Photosensitivity-Castles necklace))

Vitamin B6- Pyridoxine

Its coenzyme form is pyridoxal phosphate.

Seizures, mental disorders, anemia, rashes, glossitis

Vitamin B12

Causes of Vitamin B12 Malabsorption

• Pancreatic insufficiency.
• IF deficiency/ Atrophic gastritis / Autoimmune gastritis / Type A gastritis.
• Blind loop syndrome - Excess colonic microorganisms.
• Terminal ileum - Crohn's disease.
• Regional ileitis.

Schilling's test doesn't diagnose the vitamin B12 deficiency.

Adenosyl B12 causes paraesthesia and SACD (Subacute combined degeneration)

Methyl B12 causes Macrocytic anemia and Homocystinuria.

Vitamin 

Important information and RDA

Diseases caused

Vitamin A 

(Retinol,Retinal, Retinoic acid)

• Adult men: 1000 ug/day
• Adult women: 850 ug/day
• Pregnancy: 900 ug/day
• Lactation: 950 ug/day
• Children: 400-650 ug/day

Vitamin A TOXICITY causes Pseudotumor cerebri (no tumor, but there will be an increase in the intracranial tension with hypertension, bradycardia, vomiting, and headache), Bony exostosis, and Hepatomegaly.

Ocular manifestations

XN: Night blindness or nyctalopia (XN)

X1A: Conjunctival xerosis

X1B: Bitot's spots

X2: Corneal xerosis.

X3A: Corneal ulcer involving 1/3rd of the cornea.

X3B: Corneal ulcer involving more than 1/3rd of the cornea.

XS: Corneal Scar

XF: Xerophthalmic fundus

Skin manifestations

Phrynoderma(follicular hyperkeratosis) 

Xerophthalmia

Bitot's spots 

Keratomalacia

Corneal opacity

Vitamin E- Tocopherol 

• RDA of Vitamin E
• Male: 10 mg /day
• Female: 8 mg/day
• Pregnancy: 10 mg/ day
• Lactation: 12mg/ day
• If a person takes selenium, the Vitamin E requirements will be reduced
• Vitamin E toxicity will present with a hemorrhagic tendency 

hemolytic anemia (rare)

VITAMIN K

• Vitamin E toxicity will present with hemolytic anemia
• Vitamin K-dependent coagulation factors will not be activated without the active form of vitamin K. 

bleeding

VITAMIN D

• Normal Level of Vitamin D:30 to 80 ng/ml.
• PDA: 

For adults 19 years and older, it is 600 IU (15 mcg) daily for men and women, and for adults >70 years, it is 800 IU (20 mcg) daily.

• Hypocalcemia. 
• Secondary hyperparathyroidism