Fat Soluble Vitamins

Question 1

What is the toxicity, storage, bioavailability, and excretion of water soluble vitamins?

Answer 1

Toxicity: Low
Storage: Generally not stored, except B-12
Bioavailability: highly absorbed from diet
Excretion: really excreted

Question 2

What is the toxicity, storage, and bioavailability of fat soluble vitamins?

Answer 2

Toxicity: Potentially toxic with excessive intake
Storage: Accumulate in body
Bioavailability: require absorption of dietary fat and a carrier system for transport in blood

Question 3

What are six situations that put patients at risk for micronutrient/vitamin deficiency?

Answer 3

1 - Primary inadequate food intake or inadequate variety in diet.
2 - Increased nutrient requirements not met by food selections
3 - Increased metabolic demands
4 - Malabsorption/Maldigestion
5 - Interactions of nutrient with drugs or medical treatment
6 - Requirements for pharmacological doses

Question 4

What is the function and signs of deficiency or toxicity of Vitamin A?

Answer 4

Function: Essential in the Photochemical process of vision, maintenance of conjunctival membrane and cornea, critical for epithelial cellular differentiation and proliferation.

Signs of deficiency:
Night blindness, xerophthalmia (dry corneas) spots on sclera
Immune deficiency, dysregulation of immune response, Vit A supplementation decreases pediatric mortality 23-34%
Abnormal epithelia, linings become dry, flattened, keratinized
Used in treatment of measles, reduces morbidity and mortality.

Toxicity: Only occurs with preformed Vit A, not beta-carotene, Vomiting, Inc ICP, headache, bone pain, bone mineral loss, liver damage, death, birth defects

Question 5

What are the food sources and risk of deficiency of Vitamin A?

Answer 5

Food sources: Liver, dairy products, egg yolks, fish oil, deep yellow, orange, green veggies (spinach, carrots, broccoli, pumpkin)

Risk of deficiency: Low intake or low fat intake (less than 5% of diet), fat malabsorption (liver/pancreas disease), protein energy malnutrition.

Question 6

What is the function and signs of deficiency or toxicity of Vitamin D?

Answer 6

Function: Acts as a hormone to maintain intra and extracellular Ca within physiologic range. Stimulates Ca and P absorption from intestines, kidneys, and bones. Innate immune function, cellular growth and differentiation.

Deficiency: Rickets (failure of maturation of cartilage and calcification: bowed legs, painful bones, fractures), linked to wide range of autoimmune and other diseases,

Toxicity: Hypercalcemia, vomiting, seizures, nephrocalcinosis, soft tissue calcification
(Vit D = Ca++)

Question 7

What are the food sources and risk of deficiency of Vitamin D?

Answer 7

Food sources: Precursor (dehydrocholesterol) in skin is converted by UV rays to cholecalciferol (Vit D3). D3 from fish liver oils, fatty fish, egg yolks. D3 from animal sources, D2 from plant/algae sources (D3 2-3x more active than D2)

Deficiency: Lack of adequate sun exposure, low dietary intake, malabsorption (cystic fibrosis, liver disease, proximal small intestine disease, lipase inhibitors), breast fed infant if mother deficient, dark skin, obesity (inc storage in fat), liver or renal disease (no activation of D with CALCITRIOL),

Question 8

What is the function and signs of deficiency or toxicity of Vitamin E?

Answer 8

Function: Antioxidant, free radical scavenger, cell membrane stabilizer

Deficiency: neurologic degeneration, loss of deep tendon reflexes, spinocerebellar ataxia, neuropathy, ophthalmoplegia, incoordination, loss of vibration and position sense, hemolytic anemia (antioxidant actions)

Toxicity: coagulopathy (very large doses inhibit Vit K dependent factors) megadoses for protection against heart disease and cancer are not supported by current research.

Question 9

What are the food sources and risk of deficiency of Vitamin E?

Answer 9

Food sources: polyunsaturated vegetable oils, wheat germ

Risk of Deficiency: Prematurity, fat malabsorption syndromes, short gut syndrome, Cystic Fibrosis

Question 10

What is the function and signs of deficiency or toxicity of Vitamin K?

Answer 10

Function: Essential for the carboxylation of coagulation proteins (II, VII, IX, X)

Deficiency: Prolonged coagulation time, hemorrhagic disease of the newborn, bleeding into skin (purpura), GI tract, CNS.

Toxicity: none noted

Question 11

What are the food sources and risk of deficiency of Vitamin K?

Answer 11

Food sources: Leafy vegetables, fruits, seeds, synthesis by gut bacteria (susceptible to antibiotics)

Risk of deficiency: Newborns (poor placental transport, sterile gut, low clotting factors), breastfed newborns (great milk is low in K), fat malabsorption syndromes, chronic antibiotic use.

Question 12

In what vitamin deficiencies are rash/skin findings noted?

Answer 12

Vitamin K (purpura)
Vitamin A
Niacin (Vitamin B3)
Vitamin C

Question 13

In what vitamin deficiencies are neurologic symptoms noted?

Answer 13

Vitamin E
Thiamin (B1)
Niacin (B3)
Cobalamin (B12)
Pyridoxine (B6)
Vitamin C

Question 14

In what vitamin deficiencies is anemia noted?

Answer 14

Vitamin E (Hemolytic anemia)
Vitamin K (coagulopathies)
Folate
Cobalamin (B12)
Pyridoxine (B6)
Vitamin C

Question 15

In what vitamin deficiencies are eye/vision problems or immune dysfunction noted?

Answer 15

Vitamin A

Question 16

In what vitamin deficiencies are Rickets, osteopenia or malaria noted?

Answer 16

Vitamin D

Question 17

In what vitamin deficiencies are mouth lesions noted?

Answer 17

Riboflavin (B2)
Folate
Cobalamin (B12)
Pyridoxine (B6)
Vitamin C