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• If withdrawn from the diet, deficiency results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?

vit. b12= cobalamin

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

info on FOLATE, common names? what is primary coenzyme form?, what vitamin is it closely involved w? what does liver do with folate? is it in all flours in CAN

• common name= folacin, folic acid

• primary form = THF-tetrahydrofolate

• roles:

◦ Transfers 1-carbon compounds during

metabolism

 Synthesizes DNA

 Regenerates methionine from homocysteine

• works with vit. B12: Converts vitamin B12 to coenzyme form, 

• ALSO vit B12 is used to make folate

• Liver converts excess folate to bile, it can be reabsorbed repeatedly (into bloodstream etc)

• bioavailability differs based on source (supplement vs food)

  WHITE flour must be fortified with synthetic folate mono glutamate (since 1998, has reduced neural tube deficiency)

what are two forms of folate? how do they differ?

Monoglutamate -supplement, 1.7x more bioavailable bc already in MONO form

polyglutamate- Food, less bioavailables

Folate and B12 absorption metabolism, what happens in intestine, in cells, what is inactive from, how does it become inactivated, once activated what does it do?

what are folate recommendations? how is total folate calculated? what are RDA rec. for 14+ and during pregnancy?

RDA age 14+—> 400ug

Pregnancy —> 600ug

what are dangers of folate deficiency during pregnancy, what is affected? what are supplementation recommendations?

• dangers= neural tube defects, can lead to death

• Supplementation:

folic acid 400ug/day

start one month bf first conception through first trimester

what does folate deficiency look like? what are 2 types of causes? what is toxicity lvls?

deficiencies will impair cell division and protein synthesis:

◦ Megaloblastic anemia

◦ GI tract deterioration, smooth red tongue

◦ Mental confusion, irritability, fatigue

◦ Elevated Homocysteine/CVD Risk

◦ Drug interactions

◦ Neural tube defects – inadequacy pregnancy

2 cause types:

• Primary cause: inadequate intake

• Secondary cause: unusual metabolism or impaired absorption (eg GI tract injuries that hinder absorption and disrupt enterohepatic circulation)

Toxicity: UL=1000 ug; Set because of supplements, fortification can mask B12 deficiency symptoms

overall summary of B vitamins, deficiencies, toxicities food sources

overview of antioxidant nutrients, how do vit VS minerals act as antioxidants? 

ANTIOXIDANTS WILL:

• Protect cells from oxidative damage

 Vitamins quench free radicals

VS

 Minerals act as cofactors for enzymes

Phytochemicals

 Oxidation is part of normal metabolism

 Unpaired electron = free radical that Damages lipids, DNA, RNA, proteins

 Antioxidants neutralize free radicals

overview of antioxidants in food,

what is oxidative stress effects, defence?

• free radicals are the ‘bad guys’.

• they damage lipids-Damage cell membranes, DNA, proteins

Free radicals target structures with double bonds or rich in electrons, which are easier to oxidize.

• effects= cancer, CVD, cataracts, compromised immune function

• antioxidants are defence

how does free radical damage affect DNA and RNA, PUF, vs proteins? what does it all lead to? 

ALL leads to cell damage, aging, diseases

what is vit. C functions, what is it a cofactor for? how does it act as antioxidant? how can it be ‘reactivated, what is this process called?

Cofactor For

1)Collagen

 bone, teeth development

 “cement”, scar tissue, wound healing

2) Many  rxn

 hormone synthesis

 Synthesis of neurotransmitters

Role as antioxidant: 

 Immune system antioxidant

 Defends against oxidative stress, ree radicals to help prevent disease

Recycling process= recycling active forms of Vit. C 

what are specific roles of vit C? what prevents scurvy and when does it apprea, what is max absorption? what is relationship to smoking?

Roles:

• Enhances iron absorption

•  Stressed state  increases vitamin C needs—> When stressed: Adrenal glands secrete vit C

• Common cold

◦ Slight but consistent shortening of cold duration —> Deactivates histamine

Scurvy:

-10mg prevents scurvy symptoms, but

-scurvy appears visible @ 1/5 optimal lvls

-symptoms=Bleeding gums, breaking of capillaries (smell red spots) Inadequate collagen, wound healing ceases, teeth become loose, skin

becomes dry, rough, and scaly, Sudden death from massive internal bleeding

Absorption:

-200ug max absorption, rest is excreted 

-Smoking cigs increases needs: bc it increases oxidants so antioxidants are needed

what happens with vitamin C overdose/ what are thoughts? 

Pharmacological vs Nutritional Supplement

 Could Decrease length and severity of colds?

◦ placebo effect  OR actual histamine affect as Vit C deactivates histamine??

◦ May relieve some symptoms…

Disadvantages:

◦ False positive urinalysis

◦ Drug interactions

◦ Oxidative stress: interaction with iron

◦ Kidney stones

◦ Rebound deficiency when pills stopped???

◦ Vit C UL- 2000mg

what are common forms of vit and mineral supplements? what are some dangers?  how big of an industry? 

• Form (chewable, liquid, pill)

• Content of dose(below UL)

• Misleading claims (organic, natural, high potency)

• 50 billion in N.A, expensive 

how are vit and mineral regulated in canada? what is NNHP? NPN?? DIN?

regulated by health canada

who actually needs supplements?

Specific nutrient deficiencies

 Low energy intakes

 Vegans and older adults with atrophic gastritis

 Lactose intolerance/milk allergies

 Certain medications

 Certain stages of life cycle

 Inadequate milk intake, sun exposure, dark

skin

 People w diseases, infections, injuries

who should NOT take supplements -4

1. men—> iron

2. smokers—> beta carotene

3. post-menopausal women—> iron, vit A

4. Surgery patients, vit E