vitamins speed run

FSV = fat soluble vitamin, WSV= water soluble

Transport of FSV

Transported through lymph and delivered by bloodstream. Packaged in chylomicrons and lipoproteins.

Storage of vitamins

FSV are not readily excreted— stored in liver & adipose

WSV are excreted rapidly

Toxic effects of vitamins is most likely in

Vitamin A & D

Vitamin A is needed where?

The retina, if vit A is depleted, dark adaptation is impaired—results in night-blindness. (Vit A affects Rods)

Deficiency or excess of vitamin A in growth & development leads to what?

Lack of & excess vitamin _ during fetal & embryonic development causes birth defects & mortality.

Vitamin A deficiency disease

Eyes:

night-blindness

Mucus loss

Bitot’s spots

Skin:

follicular hyperkeratosis

How much sunlight a week provides 80-100% of Vitamin D?

2-3x week for 10-15 min

Functions of vitamin D

Maintains calcium & phosphorus homeostasis

Maintains bone health

Vitamin E

Tocopherol—most active form is alpha-tocopherol

Made of 4 tocopherols & tocotrienols

Vitamin K function

Synthesis of blood clotting factors & bone metabolism

All B vitamins are what?

Coenzymes, function in energy metabolism

In foods, present as B-vitamins or coenzymes

Thiamin defincieny

Beriberi: peripheral neuropathy & weakness

Dry beriberi: symptoms are nervous & muscular sys

Wet: nervous & cardiovascular

Infantile: breast milk contains insufficient thiamin

Cerebral (WKS): occurs with alcohol abuse

Riboflavin

“the yellow enzyme” found in milk, enriched grains, eggs, & meat

Riboflavin coenzyme

Participates in oxidation-reduction reactions

Niacin

Synthesized from tryptophan

Also participates in oxidation-reduction reactions

Niacin in the body

Bioavailability is low in some grains. It’s bound to a protein that can be released by soaking in calcium hydroxide (lime water)

Folate (B9)

Folic acid refers to synthetic form = only 1 glutamate present

Niacin UL RDA & DV

UL: 1mg

RDA: 400ug

DV: 400ug

Folate deficiency

Megaloblastic anemia

Deficiency first affects cells synthesizing DNA

RBC remain large & immature

Folate deficiency: growth & development

Neural tube defects—spina bifida & anencephaly

Vitamin B-12

known as cobalamin (contains cobalt). Plants do not synthesize, only found in animal products

Absorption, transport, storage & excretion of B12

Binds to r-protein in somach. Vit B12 combines with intrinsic factor to aid aborption.

Bound to transcobalamin II

Functions of B12

Required for 2 enzymatic fxns:

Formation of methionine from homocysteine & metabolism of some fatty acids by methylmalonyl mutase. Vi

Vitamin C

Known as ascorbic acid. Primary functions are electron donor. least stable vitamin

Functions of Vitamin C

Primary: electron donor

Antioxidant

Synthesis of collagenf

Vitamin C deficiency

20-40 days no Vit C = scurvy