Ch 10: Water Soluble Vitamins

Vitamin B5 - Pantothenic acid

needed to synthesize coenzyme A, heme, cholesterol, bile salts, phospholipids, fatty acids, and steroid hormones

deficiency is very rare but symptoms include fatigue, insomnia, depression, irritability, and burning feet syndrome

AI: 5mg/day, no UL

Water soluble vitamins

any extra is excreted so no UL; toxicity is more common for fat soluble vitamins

Vitamin B6 - Pyridoxine

synthesizes non-essential amino acids

without this, you need to consume all 20 amino acids

needed to convert

Deficiency:

microcytic hypochromic anemia

seizures and convulsions in infants due to heating infant formula

UL 100 mg/day - can cause severe neurological issues

Vitamin B7 - Biotin

raw egg whites bind with biotin - overconsumption of raw egg whites (avidin) can lead to biotin deficiency

deficiencies: depression, hallucinations, skin irritations, infections, hair loss

no UL

Vitamin B9 - Folate/Folic acid

body tends to absorb folate from supplements better than from food which is an exception

bioavailability from food is low (50%) and also not that common in food - fortified cereal and orange juice, okra, legume, leafy greens

important for growth, maintenance, repair of tissues esp. during fetal growth

deficiency in early pregnancy can lead to neural tube birth defects

AI is more for pregnant women, UL 1000 mcg/day

Anencephaly

more severe neural tube defect in the head area, usually fatal for babies

Spinal bifida

neural tube defect; improper closing of bottom of spine

One-carbon metabolism

transfer of 1 carbon unit (methyl groups -CH3) for processes in the body; important for amino acid metabolism and making purines and

ex. having enough b9 folate and b12 cobalamin can help lower homocysteine (protein associated with increased risk of heart disease)

Megaloblastic macrocytic anemia

vitamin b9 folate/b12 cobalamin deficiency

immature red blood cells (megaloblasts)

B12 - Cobalamin

last B vitamin to be discovered

contains Cobalt and Nitrogen

mostly found in animal sources, bacteria, fungi

absorption depends on intrinsic factor (protein made in stomach)

deficiency: common in vegans, older adults (decreased synthesis of intrinsic factor)

can lead to pernicious anemia which looks similar to megaloblastic anemia

folate deficiency can mask cobalamin deficiency

no UL

Vitamin C - Ascorbic acid

important antioxidant, plays a role in almost every physiological process

made by glucose by plants and animals but humans can’t synthesize

peppers have more than citrus!

easily destroyed by light and heat

helps with collagen production

enhances iron, copper, and chromium bioavailability

strengthens immune function

UL 2000 mcg/day

Antioxidants

electron donors involved in redox reactions

enzymes can get oxidated during cellular processes which does damage, and antioxidants can help with repair

ex. enhance non-heme iron absorption

Fe2+ is better absorbed than Fe3+ and vitamin C helps the body absorb Fe3+ by donating an electron to convert it to Fe2+

Vitamin C Deficiency

Scurvy

bleeding gums, skin irritation, bruising, poor wound healing

sailors recovered after eating citrus fruits

2 non-essential water soluble vitamins

Choline + Carnitine

Choline

can be made in the body from methionine

found in cell membranes (animal-based food contains choline)

functions: muscle contraction, synthesizing phospholipids (cell membrane), acetylcholine (neurotransmitter), muscle control, also a one-carbon donor

potential deficiencies: fatty liver, liver damage, muscle damage, under-consumed in older infants - add meat and eggs to infants diet when weaning off of formula

overconsumption: too much sweat, fishy BO

2 ways to lower homocysteine

one-carbon donation through:

choline

folate and cobalamin cycle

Carnitine

structurally similar to an amino acid

non-essential for adults but not newborns

required to transport fatty acids across membranes (burning fats for ATP)

deficiency is uncommon so eating more may not help

2 exceptions: easier to absorb from supplements rather than food

folate + cobalamin