Class 14- Intro to h20, vitamins, water, soluble antioxidants

summary of importance of micronutrients

• needed in small amount, non-caloric

• Not endogenously synthesized at rates sufficient to meet requirements

• Perform specific biological functions

• If withdrawn from the diet, deficiency results

• Consider: Absorption, Transport, Storage, Excretion, Toxicity Interactions and Requirements

what intermediary micronutrient roles

B complex

what are structural micronutrient roles

Ca and P in bones, minerals in metalloenzymes, hemoglobin

what hormonal micronutrient roles

1. Vit A as retenoic acid—> cel differentiation

2. Vit. D as calcitriol—> calcium availability

in order to be a vitamin..

NOT being able to be indigenously synthsised in body

-perform key functions

what are antioxidant micronutrient function

vit. A,C, E

mineral→ Se

what are electrolyte micronutrient function

Na, k, Cl

what are main differences in Vit an Minerals for structure, function, food content, solubility

what is bioavailability ? what is it influenced by? 

Includes the rate and the extent to which a

nutrient is absorbed and then actually used

◦ Influenced by:

 Efficiency of digestion

 Transit time

 Other foods present - e.g. binders, fibre

 Food preparation/ cooking method

 Source of the nutrient—> aka Synthetic and fortified foods influence bioavailability

overview of vitamins

Non-caloric nutrients

 Body cannot synthesize or not enough made to meet needs

• Organic: in fresh foods but they can be readily destroyed during processing/ heating

• they are Individual units

Found in different forms: active form or precursors (vitamers or provitamins)

Can be broken down and reformed

 Food: Needed in small amounts from the diet (mg or μg),

 Bioavailability: varies

 Required for metabolism, growth & maintenance of health

 Deficiencies may lead to diseases

what are fat soluble vitamins

vit A, D, E,K

what are h20 soluble vitamins (9)

B VITAMINS:

• thiamin, B1

• riboflavin, B2

• Niacin, B3

• Folate

• Vit. B12

• Vit. B6

• Biotin

• Panthothenic acid

Vitamin C

how are h20 soluble absorbed, transported, stored, excreted, toxicity? requirements approx

how are fat soluble absorbed, transported, stored, excreted, toxicity? requirements approx

only need periodically because stored WITH fat

how are MAJOR minerals  absorbed, transported, stored, excreted, toxicity? requirements approx

how are MINOR minerals absorbed, transported, stored, excreted, toxicity? requirements approx

what are 4 characteristics water-soluble vitamins share?

1. dissolve in h20

2. are easily absorbed and excreted

3. rarely meet toxic levels

4. NOT extensively stored in tissues

what happens with Vit. B deficiencies?

how do enzymes act as coenzymes

required for most enzymes to function!

what are common roles of B vitamins in brain, muscles, bone, liver, digestive tract

overview of vit. as coenzymes in pathways: leading to acetyl coA, TCA cycle, ETC —> catabolic, and amino acid, glycogen, fat —> anabolic 

What are Thiamin roles, what are 2 forms of deficiencies 

• Part of coenzyme thiamin

pyrophosphate (TPP)

•  Assists in energy and EtOH

metabolism

• Conversion of pyruvate to acetylCoA: TCA cycle, Nerve activity and muscle activity

• its easy to get, Average intake meets or

exceeds rec’s with adequate kcal

Deficiency: Beriberi: wet(edema) vs dry(musculature)

-High risk with EtOH abuse, malnourished, food insecure

What are B6 roles, deficiency, toxicity? what can destroy it?

• B6 aka riboflavin

• a conenzymes in many energy rxns: 

Flavin mononucleotide (FMN)

Flavin adenine dinucleotide (FAD)

• it Accepts and donates 2 H (TCA cycle → Electron transport chain)

Deficiency:

◦ Inflammation of membranes- mouth, skin, eyes

 Toxicity: No UL

• UV light destroys Riboflavin!

what are B3 , structures, what is is apart of? how can it be made in body and what it the equivalency?

B3 aka Niacin

• Two chemical structures:

 Nicotinic acid and nicotinamide

• Part of two coenzymes:

 Nicotinamide adenine dinucleotide (NAD)

 NADP (phosphate form)

• can be Made from tryptophan (Trp): Occurs only AFTER  protein synthesis needs have been  met

• Niacin equivalents (NE):

1 mg niacin + 60 mg of Trp = 2 NE

so 60mg=1mg niacin

what is B3 deficiency ? is toxicity a concern? 

Niacin B3 deficiency:

PELLEGRA

4D symptoms: Dermatitis, diarrhea , dementia, death

Toxicity—> rare, must be consuming 3-4x RDA OR medications (niacin flushing)

what are vit. B6 forms (what are they converted to?), what is it involved in?

• three forms: pyridoxal, pyridoxine, pyridoxamine—> All converted to coenzyme pyridoxal phosphate (PLP)

Functions:

• Stored in muscle

• Amino acid metabolism as coenzyme: Transfers amino group to keto acid, Tryptophan to niacin, serotonin

• Synthesis of heme, nucleic acids, lecithin

What are B12 key thing about structure, what is it CLOSELY related to? individual roles? why is it so important for digestion and absorption ? stored in?

• large molecule, has centre Co (cobalt mineral)

WORKS WITH B12 for activation:

◦ Regeneration of methionine

◦ Synthesis of DNA and RNA

Roles of vitamin B12: 

• Maintains sheath on nerve cells

• Bone cell activity and metabolism

VERY Impot. for Digestion and absorption

◦ Stomach → require hydrochloric acid(HCl) and intrinsicfactor (IF) : HCL and pepsin release B12 from proteins bound to it, then B12 binds to stomach IF then absorbed in terminal ileum

◦ Enteropathic circulation for both folate and B12 - Secreted in the bile and reabsorbed

• stored in liver

what are common b12 foods, common deficiencies?

food: ONLY animal sources Food: only in animal sources (or fort. plant based)

• Best bioavail: Fish, milk, eggs

• Vegan: fortified plant beverages, B12 fortified nutritional yeast

• Inactivated by microwave heating

deficiencies:

• common in Vegan diet

• Or Poor absorption if lack of IF and/or HCI, Rx interactions: antacids

• Deficiency sex: fatigue, dementia, peripheral nerve degeneration - paralysis, anemia