Vitamins-Water Soluble Flashcards
What are the shared characteristics of Water Soluble Vitamins
- Dissolve easily in water
- Easily absorbed and excreted
- Not stored extensively in tissues
- Seldom reach toxic levels
General B Vitamin characteristics
- Typical role is “coenzyme”; activates enzymes
- Primarily used in Energy Metabolism, cell multiplication, and protein metabolism
Five B vitamins participate in…
the release of energy from carbohydrate, fat and protein (energy metabolism): Thiamin, Riboflavin, Niacin
One B vitamin helps…
the body interconvert amino acids: B6
Two B vitamins help…
cells multiply; B12 and Folate (folic acid)
Which cells are impacted by a vitamin B deficiency?
ALL. But the deficiency of a single B-vitamin is RARE.
people don’t eat single nutrients
Thiamin function
energy metabolism
Thiamin sources
many
Thiamin major deficiency/toxicity
(Beri Beri squishy leg) RARE//RARE
Population subgroup it affects [thiamin]
Alcoholics. Alcohol abuse leads to severe thiamin deficiency; displacement.
Thiamin RDA
M: 1.2mg/day
W: 1.1mg/day
Thiamin is…
B1
Riboflavin is…
B2
Riboflavin function
energy metabolism
Riboflavin sources
many
Riboflavin deficiency//Toxicity
RARE//RARE
Riboflavin population subgroups?
UNCLEAR
Riboflavin RDA
M: 1.3mg/day
W: 1.1 mg/day
Niacin is…
B3
Niacin RDA
M: 16 mg/day
W: 14mg/day
Niacin sources
many INCLUDING tryptophan conversion!!!
Niacin deficiency//toxicity
Pellagra-Rare; corn low in tryptophan for conversion (dermatitis)//
RARE; the Upper Limit is double the RDA but over the counter products are 10X the RDA!
How can tryptophan help meet niacin needs
It can be converted in substantial proportions to niacin.
Niacin special subgroup
People using corn as a staple, and those with lipid disorders
B6 primary function
non-essential amino acid conversion
B6 sources
many
B6 major deficiency//toxicity
RARE, general symptoms//RARE
B6 metabolism trick
helps convert tryptophan to niacin and serotonin
B6 population subgroups
Women trying to treat PMS, adults trying to treat carpal tunnel syndrome with ineffective supplement doses
Folate is…
B9
Folic acid/folate deficiency
is the most common vitamin deficiency in US
Folate RDA
Adults 400 mcg/day
over that synthetic for pregnancy.
Folate sources
FRESH/RAW VEGGIES
Folate function…
1-carbon transfer; RNA and DNA
Without B12, folate…
is trapped in one of its 5 forms and can’t be utilized
Public health debate
decision to fortify wheat flour, making the primary source of folic acid a food with a low nutrient density
Why is there a tolerable upper intake level for folic acid
To prevent masking a vitamin b12 deficiency
Relationship between folate and homocysteine (a risk factor for heart disease in observational studies)
Folate (and B12) lowers homocysteine because it converts it to methionine.
But it doesn’t save lives.
What does folate fortification prevent
Neural tube defects
B12 RDA
2.4 mcg/day for adults
lowest of any nutrient with an RDA!
B12 function
methyl group transfer, nerve sheath maintenance
B12 main sources
Animal foods
B12 major deficiency//toxicity
Anemia, nerve damage//NONE.
B12 digestion issues
Intrinsic factor needed, absorbed in the ileum
B12 metabolism tricks
Link to folate metabolism’s methyl trap, injections needed for pernicious anemia or people without an ileum
B12 subgroups
strict vegetarians, pregnant women.
Biotin & Pantothenic Acid
B-Vitamins
Active in energy metabolism
Presence in food is widespread
Deficiency is rare
Vitamin C tolerable upper intake levels
2,000 mg/day
Does vitamin C help colds
no
Vitamin C primary function
antioxidant, collagen synthesis
Vitamin C sources
plants, veggies, citrus
Vitamin C deficiency//toxicity
Scurvy// Several toxicity issues ex: DNA damage
Vitamin C digestion
helps with iron absorption
Vitamin C metabolism tricks
Regenerates other antioxidants
Vitamin C subgroups
smokers with low to no veggies and fruits
How does vitamin C help prevent scurvy
Vitamin C keeps iron in its reduced form (Fe+3 –> Fe+2) and increases non-heme iron absorption. Iron is needed in its reduced state as part of a metallo-enzyme that is used for post-translational hydroxylation proline and lysine in collagen protein.
These are the four vitamins that are fortified in grain.
Niacin (B3), Folate (B9), Thiamin (B1), and riboflavin (B2). (Iron also fortified, but is a mineral)
Primary deficiency in this can lead to Macrocytic Anemia.
Folate (B9).
Animal foods are a main source of this vitamin because of the bacteria they consume on their unscrubbed vegetables
B12
