HTHSCI 3BB3 - F2023 - 5A - Water-soluble Vitamins

What are vitamins?

organic compounds required to maintain health

a low-fat diet may inhibit absorption of....

fat-soluble vitamins

What is required for transport?

carrier proteins

Provitamin

An inactive form of a vitamin that the body can convert to an active form. An example is beta-carotene.

Whole grains contain which vitamins?

Thiamine

Riboflavin

Niacin

Pantothenic Acid

Vitamin B6

Folate

(many are added back as enrichment)?

Vegetable and fruits contain which vitamins?

Riboflavin

Niacin

Vitamin B6

Folate

Vitamins C,A,K,E

Canadians are not getting enough

Vitamin C and Folate

Fortified foods

have nutrients added that are NOT normally found in that food (vitamin D in milk)

Enriched foods

have nutrients added BACK that have been removed during processing (enriched white flour)

Dietary supplements:

Supplements can be a source of vitamins in the diet

Can contain a combination of vitamins, minerals, herbs, amino acids, botanicals, extracts

Cannot replace foods consumed in the diet

Caution should be exercised as regulation is not as stringent as for pharmaceuticals

Supplement Toxicity

Toxicity can occur if consumption goes beyond established UL

What regulates the use of natural health products and non- prescription drugs?

Health Canada's Natural Health and Non-Prescription Products Directorate

Licensed products that have been reviewed and approved for use by Health Canada have an:

eight-digit Natural Product Number (NPN) or Homeopathic Medicine Number (DIN-HM), which must appear on the label

Approximately 40-90% of vitamins are absorbed in the

small intestine

Fat-soluble vitamins require:

dietary lipids for absorption (micelles)

Water-soluble vitamins may require:

transport molecules or specific molecules in GI tract

Water-soluble vitamins are less likely to be present at

toxic levels

Water soluble vitamins solubility in the blood allows them to...

filtered out and excreted by the kidney when ingested in excess

Water soluble vitamins tend to be

less stable and tissue depletion can occur more readily

Most are converted to co-enzymes that function in:

energy generation and hematopoiesis (blood cell formation)

Because most water-soluble vitamins are involved in energy generation and blood cell development, what do you think are likely side effects of deficiency?

Anemia, low energy

What are the B vitamins?

Thiamin (B1)

Riboflavin (B2)

Niacin (B3)

Biotin

Pantothenic acid

Vitamin B6

Folate

Vitamin B12

Thiamine nutrition information:

RDA:1.1-1.2mg/day

Toxicity: None Reported

UL:Notdetermined

thiamine bioavailability

Sensitive to heat,oxygen,low-acid

Anti-thiamin factors can destroy the vitamin in food (e.g. raw shellfish and coffee)

Thiamine use in the body

- Thiamine pyrophosphate (TPP,ThDP, TDP)

- energy producing reactions where CO2 is released

- synthesis of acetylcholine (neurotransmitter)

- Used in the production is ribose, a precursor to RNA

Thiamine deficiency

Beriberi

Characterized by lack of energy, weakness and neurological symptoms

Thiamin deficiency can be a result of alcohol use disorder

Can also result in a neurological condition called Wiernicke-Korsakoff syndrome

Thiamine supplementation

Claims to increase energy, improve mental function, prevent heart disease

• Only if diet is deficient in thiamine

Riboflavin nutrition

RDA:1.1-1.3mg/day

Toxicity: None Reported•

UL:Notdetermined

riboflavin bioavailability

Sensitive to light

Opaque milk cartons are used to preserve riboflavin in milk

Riboflavin use in the body

Used to make FAD/FADH2,FMN

Can transfer electrons to different

molecules

Used in energy producing reactions and transporting electrons to the electron transport chain

Used in the conversion of other vitamins to active forms

Riboflavin deficiency

- deficiency is rare

- Ariboflavinosis

- Increased alcohol consumption is associated with deficiency of many b vitamins

- Symptoms include poor wound healing, inflammation of the eyes, lips, mouth, and tongue and confusion

Riboflavin supplementation

Claims to increase energy, support eye and skin health

• Only if diet is deficient in riboflavin

Niacin Nutrition

RDA:14-16mgNE/day

• Toxicity: Flushing, nausea, rash, tingling extremities

• UL: 35mg/day from fortified food/supplements

associated w corn

Niacin Bioavailability

Can be made in the body from the amino acid tryptophan, but only when there is enough tryptophan for protein synthesis

Niacin use in the body

NAD+/NADH;NADP+/NADPH

Transfers electrons to other molecules

Used as an electron transporter to generate ATP (energy)

so widespread that deficiency causes damage throughout the body

Niacin deficiency

Pellagra is the result of diet deficient in niacin

Symptoms are 3 D's:dermatitis, dementia and diarrhea

If left untreated, results in death

Niacin supplementation

Claims to increase energy• Only if diet is deficient in niacin

Biotin nutrition

NO RDA à AI: 30 μg/day

Toxicity: None Reported

UL: Not determined

animal studies with rats fed protein from raw egg

Biotin bioavailability

produced by bacteria in the GI tract and absorbed into the body

Food containing raw egg should be avoided because the protein avidin in the egg white binds biotin very tightly, making it unavailable for absorption

Biotin use in the body

Co-enzyme for enzymes that add a-COOH group to molecules

• Used to generate molecules needed for citric acid cycle and glucose synthesis

Biotin deficiency

- rare

• Symptoms including nausea, thinning hair, loss of hair colour, a red skin rash, depression, lethargy, hallucinations, and tingling of the extremities gradually appear.

Biotin supplementation

Claims to treat hair loss, brittle nails • Only if diet is deficient in biotin

Pantothenic Acid

NO RDA: AI:5mg/day

Toxicity : None Reported •

UL:Not determined

Pantothenic Acid bioavailability

Susceptible to heat and low-or high-acid conditions

Pantothenic Acid uses in the body

- Part of CoenzymeA(CoA), an important part of Acetyl-CoA

• Used in the synthesis of cholesterol

Pantothenic Acid deficiency

rare

• Can occur as part of multiple B- vitamin deficiency

What do Thiamin (B1), Riboflavin (B2), Niacin (B3), Biotin, and Pantothenic acid have in common?

metabolize energy directly

What do Vitamin B6, Folate, and Vitamin B12 have in common?

related to anemia

Vitamin B6 nutrition

RDA: 1.3-1.7mg/day, increasingwithage•

Toxicity: Numbness, nerve damage•

UL:100mg/day

added for enrichment

Vitamin B6 bioavailability

Easily destroyed by heat and light

• Easily lost during processing

Vitamin B6 Uses in the body

amino acid metabolism

transamination and deamination reactions

synthesize hemoglobin

form white blood cells

conversion of tryptophan to niacin

Metabolism of glycogen

Synthesis of neurotransmitters

Synthesis of myelin coating on nerves

over 100 enzymatic reactions

Vitamin B6 deficiency

- neuro: depression, headaches, confusion, numbness and tingling in the extremities, and seizures

- Anemia

- poor growth, skin lesions, and decreased antibody formation may occur because vitamin B6 is important in protein and energy metabolism

Vitamin B6 supplementation

Potential link to reduced cardiovascular disease (reduced levels of homocysteine)

Potential link to improved immunity in older adults

What amino acid has high levels in blood with CV disease?

Homocysteine

Folate is part of a group of compounds that

were part of Wills Factor and used to treat anemia during pregnancy

Folate nutrition

RDA: 400 μg DFE/day increased to 600 μg DFE/day during

pregnancy

Toxicity: None reported, but high intake may mask vitamin B12 deficiency

UL: 1000 μg DFE/day

folate bioavailability

Folate in the diet is bound to chains of the amino acid glutamate, which must be removed prior to absorption

Estimated that only 50% of dietary folate is absorbed

Synthetic folate (supplements and fortification) does not

folate use in the body

Used in amino acid metabolism

Used in the synthesis of DNA nucleotides - needed for DNA replication

Used in the methylation of DNA - silencing of gene expression

Folate deficiency

Megaloblastic anemia due to inability for cells to divide

Neural tube defects, such as spina bifida, anencephaly

Heart disease (increased homocysteine levels)

Folate supplementation

Supplemental folate masks Vitamin B12 deficiency

Because the risk of neural tube defects usually occurs prior to confirmation of pregnancy (~28 days gestation), it is advised the persons of child-bearing years to take a folate supplement

Fortification in foods has dramatically decreased the rates of neural tube defects in infants

Vitamin B12 nutrition

RDA:2.4μg/day•

Toxicity:None reported •

UL:Nodata

pernicious anemia

lack of mature erythrocytes caused by inability to absorb vitamin B12 into the bloodstream

inability to synthesize folate

Bioavailability

Found almost exclusively in animal products• It can be made by bacteria and fungi but not by

plants and animals

• Individuals who follow a vegan dietary pattern must get vitamin B12 from nutritional yeast or a supplement

Vitamin B12 Absorption

- Vitamin B12 is inaccessible within food prior to digestion.

In the stomach, acid and pepsin release it from bound proteins in food

- In the small intestine, it is bound to intrinsic factor, allowing it to bind to receptors in the ileum and be absorbed

- Very little vitamin B12 is lost in the body, therefore deficiency develops slowly

A small amount of vitamin B12 can be synthesized in the body. Where is this made?

Large intestine (intrinsic factor is only released in SI)

Vitamin B12 use in the body

Used in amino acid metabolism and the synthesis of methionine

Regenerates folate

Vitamin b12 deficiency

- Pernicious anemia due to inability to regenerate folate

- Neurological symptoms: numbness and tingling, abnormalities in gait, memory loss, and disorientation

- Vegan dietary patterns, due to lack of animal-based foods, must get it from fortified food or nutritional yeast

- Heart disease (increased homocysteine levels)

- Atrophic Gastritis

What happens if vitamin B12 deficiency is not treated?

eventually causes paralysis and death

atrophic gastritis

reduction in the amount of stomach acids impairs the ability to release vitamin B12 from food

Vitamin B12 supplementation

Advised for persons following a vegan dietary pattern

Claims include "pick-me-up" for tired individuals

• Only if someone is deficient in vitamin B12

What masks Vitamin B12 deficiency?

Supplemental folate

What is an early indicator in B12 deficiency?

megaloblastic anemia

Dietitians estimate that 1/3 of the population may have:

low vitamin B12 levels

Vitamin C deficiency was identified as

causative for Scurvy

Vitamin C nutrition

RDA:75-90mg/day

Toxicity: Extreme doses may cause diarrhea, nausea, and abdominal cramps

UL:2000mg/day

Vitamin C bioavailability

Vitamin C is unstable and is destroyed by oxygen, light, and heat

• Reactive with copper or iron cooking utensils and by low-acid conditions.

Vitamin C use in the body

- Aids in the synthesis and maintenance of connective tissue stemming from the formation of collagen

- Crosslinks collagen proteins to form stronger fibers

- Synthesis of neurotransmitters, hormones, bile acids

- Synthesis of neurotransmitters, hormones, bile acids

- Acts as an anti-oxidant

- Supports immune system

- Aids in absorption of iron

oxygen free radicals

- enter our bodies from foods and environmental toxins

- generated routinely by metabolic processes (e.g. ETC) and inflammation

- damage cell membranes, DNA, proteins and mitochondria

- implicated in aging and diseases such as cancer and cardiovascular disease

What reduces possible damaged from free radicals?

Neutralization of free radicals minimizes the possible damage

Vitamin C deficiency

Scurvy

Collagen can't be maintained, and connective tissue breaks down, wounds heal poorly, weakening blood vessels (bleeds)

Poor iron absorption = anemia

Vitamin C supplementation

- Role as an anti-oxidant and in bile acids production suggests a potential to decrease or protect against cardiovascular disease - so far evidence is lacking

- Potential role in cancer prevention

- Higher intake of fruits and vegetables (high vitamin C) decreases the risk of cancer. Maybe linked to antioxidant?

- More likely due to a better dietary pattern and not vitamin C alone

Prophylactic vitamin C supplementation

Prophylactic Vitamin C supplementation may reduce the duration of a cold

What is vitamin B12 needed for?

regenerated folate

amino acid metabolism

What is vitamin B6 needed for?

regenerated folate

amino acid metabolism

Folate dependency on B vitamins

if you don't have enough folate, vitamin B may not be affected

if you don't have enough vitamin B, folate will be affected

Why does folate mask a vitamin B12 deficiency?

anemia won't develop, however neurological issues can still occur