MedChem Vitamins and Minerals

What vitamins are easily excreted

All Water soluble + K except B12

Which vitamin is absorbed by Saturable Solute Carrier

B9

What vitamins are absorbed into the lymph

Fat soluble vitamins

What vitamins are absorbed into the blood

Water Soluble

What is enriched

Originally had, and added back after processing

What is fortified

Additionally added

Thiamine Active form

Thiamine pyrophosphate made by thiamine pyrophosphokinase

Thiamine absorption and excretion

poorly absorbed by passive transporter

excreted renally

Thiamine RDA / UL

RDA is about 1.2 mg

No UL as absorption is limiting

Thiamine physiologic functions

Creates a Carbanion and performs oxidative decarboxylation

Thiamine deficiency causes

Alcoholism of poor diet

What is Beri Beri, types, treatment

Disease from thiamine deficiency

Wet - CV, edema

Dry - CNS issues

Treated with high doe Thiamine

What is Wernicke-Korsakoff syndrome

Thiamine deficiency from chronic alcoholism, causes memory loss and encephalopathy

What is the active from of Riboflavin and how is it made

Riboflavin + phosphate → FMN + Adenine → FAD

What kind of B2 is dietary

FMN or FAD, which cannot be absorbed

Vitamin B2 absorption

Dietary FMN and FAD is degraded to riboflavin,

Riboflavin is up taken via active transport,

Converted into active forms in cells

UL on B2?

No because no observable toxicity

B2 physiological function

Hydrogen acceptor of one or two Hydrogen in redox (FAD → FADH2)

• Activates some vitamins (B3,B6,B9)

• Reduces glutathione

• production of AAs

  • breakdown of carbohydrates

What B vitamin does microflora produce

B2

What causes B2 deficiency and what is it

Ariboflavinosis is commonly caused from chronic alcoholism, absorptive disorders, or thyroid insufficiency

Vitamin B2 therapeutic use

Eye drops for post eye surgery, thin cornea, bulging cornea

Niacin active form

Converted to nicotinamide then to NAD or NADP

Niacin absorption

Consumed as NADP which is hydrolyzed to Niacin or nicotinamide for absorption

Niacin excretion

Excreted as N-methyl or glycine conjugate metabolites

Side effects of Niacin supplementation

flushing and tingling of face and neck. Nicotinamide doesn’t do this, nor inositol hexanicotinate

What B vitamin is not technically a vitamin

B3 - niacin is not technically a vitamin as it can be synthesized from large amounts of tryptophan

Vitamin B3 physiologic function

H acceptor or donor in redox reaction

What is B3 deficiency called and what causes it

Pellagra - alcoholism, isoniazid, barbiturates, anorexia, weight loss surgery

How is niacin therapeutically used

Used for hyperlipidemia

What is the active form of Vitamin B5 and how is it made

Coenzyme A (ACP), which is created by phosphorylation, L-cysteine, and adenine nucleotide

Absorption of B5

Consumed as ACP, hydrolyzed to free vitamin, taken up by SMVT,

Is there an upper limit of B5

No, but large doses may cause diarrhea

B5 physiological functions

Acyl or Acetyl group donor in biosynthesis

What causes pantothenic Acid deficiency

Severe malnutrition

Pyridoxine Active form

Activated form is phosphorylated

• interconverts between PMP, PLP, PNP

  • Major form is PLP

Pyridoxine Absoprtion

Absorbed as non-phosphorylated from, in blood as PLP, dephosphorylated for intracellular transport, rephosphorylated in cell

Pyridoxine UL

100 mg a day, because high doses can cause sensory neuropathy

B6 physiological function

Forms a Schiff base with Amino Acids, for transamination, decarboxylation and racemase reactions

• used in synthesis of niacin from tryptophan

B6 deficiency cause and effect

Alcoholism, Isoniazid, Hydralazine, contraceptives

Causes peripheral neuropathy, sideroblastic anemia

Pellagra as no niacin creation from tryptophan

Pyridoxine use

With doxylamine for N/V in pregnancy

What vitamins are redox

B2, B3, C

What vitamins are absorbed by SMVT

B5 and B7

What vitamins are produced by colonic bacteria

B2, B5, B7

Biotin (B7) Active form

covalently attached to lysine of biotin carboxyl carrier protein

Biotin absoprtion

Absorbed via SMVT

Biotin RDA and UL

RDA 0.03 mg

no UL as no observed adverse effects

Biotin physiologic functions

Carboxylation and decarboxylation

Biotin deficiency cause

Large amounts of raw egg whites that contain avidin

What test does biotin interfere with

Interferes with troponin test for diagnosing heart attacks, showing lower levels as it complexes troponin antibodies

B9 Active form

Tetrahydrofolate which is the reduced form (by B2)

B9 absorption

Absorbed as folate via active transport

What if one DFE

1 dietary folate equivalent =

1mg folate from food

0.6mg folate form fortified foods or supp with food

05 mg folate supp on empty stomach

RDA and UL of B9

Higher RDA when pregnant, UL 1 mg on supplements due to masking of B12 deficiency

B9 physiologic functions

Used in one carbon transfer reactions

1. THF + Carbon from serine:PLP

2. N5,N10-methylene THF

Needed for DNA synthesis, donating carbon to make purines

B9 deficiency cause and effect

alcoholism, weight loss

• Causes Megaloblastic anemia

  • Neural tube defects in kid

B9 Use

Leucovorin is used in preventing side effects of methotrexate, lowering levels of DHF by inhibiting BHFR

What vitamins are activated via phosphorylation

B1, B2, B3, B5, B6

Vitamin B12 active form

Many forms But:
planar corrin ring with cobalt + lower ligand is dimethyl benzimidazole + varying upper ligand

B12 sources

Animal products

B12 absorption

Exists as protein bound, must bind to IF from parietal cells and be endocytosed. Saturable

B12 UL

No UL as saturable absorption via endocytosis

B12 physiological functions

Isomerase if top is adenosyl

Methyltransferase if top is Methyl

• methionine synthesis

b12 deficiency causes

Medications that impair absorption: PPIs, H2RAs, increase in NO (inactivates B12)

b12 deficiency effects

Pernicious anemia, autoimmune destruction of parietal cells, nerve damage, often confused with megaloblastic anemia (b9)

Vitamin C Active form

L-isomer

Where is the acidic hydrogen in ascorbic acid

The hydroxyl at the base of the enol

What are some sources of vitamin C

Fruits and Veggies

How is Vitamin C excreted

Excreted as oxalate which can form kidney stones

Vitamin C UL

2g a day, but does not have many bad effects, diarrhea, acidification of urine, kidney stones

How Does vitamin C affect iron

Chelates iron, could be useful in iron poisoning, promotes absorption of non-heme iron

Vitamin C physiologic function

Electron donor in redox reactions, maintains enzyme bound metals in reduced form, scavenges ROS

• Collagen synthesis

Vitamin C deficiency name and symptoms

Scurvy - manifests as lack of collagen for connective tissues: poor wound healing, gingivitis, hemorrhaging, bone defects

Vitamin C therapeutic Uses

enhancing absorption of non-heme iron

Vitamin A definition

All retinol analogues

What kind of bonds does retinol have

All trans bonds

What is a precursor to Retinal

B-Carotene → 2 Retinal (in intestine)

What is the upper limit on Vitamin A

UL is 3 mg, only applies to retinol and ananlogues, not B-carotene

How is retinol used in Vision

Retinol →» 11-cis-retinal + opsin → rhodopsin

Rhodopsin + light → opsin + 11-trans-retinal + sight

How does opsin couple to 11-cis-retinal

Schiff Base

Vitamin A deficiency symptoms

Night blindness, overgrowth of teeth and bones in infants

Vitamin A toxicity

Increase in CSF pressure, bulging of fontanelle, blurred vision

What Vitamin A analogues are for Acne

Isotretinoin, Retinoic Acid, Adapalene, Trifarotene

What vitamin A analogues are for psoriasis

Acitretin

What vitamin A analogues are for Kaporski’s syndrome

9-cis-retinoic acid

Types of Vitamin D

D2 - ergocalciferol

D3 - cholecalciferol - from sun

What vitamins are not true vitamins

D3 and B3

Vitamin D toxicity symptoms

anorexia, weight loss, calcification of tissues

Physiologic role of Vitamin D

upregulates genes for Calcium and Phosphate absorption in the small intestine. Needed for proper bone formation

What causes rickets

Vitamin D deficiency

Vitamin E UL

1000mg

• not for food, only a-tocopherol

Vitamin E functions

antioxidant for lipid radicals

Alter enzymes for immunity anda inflammation

Vitamin E deficiency

rare but presents as neurological condition and retina damage

Vitamin E uses

• hemolytic anemia in premature infants

• macrocytic megaloblastic anemia in children

• Lower effectiveness of anticancer agents

Vitamin K deficiency

extremely rare but manifests as bleeding

Vitamin K1 name

phylloquinone

Vitamin K2 name

menaquinone

Vitamin K functions

blood clotting

K2 in bone metabolism

Vitamin K DDIs

Warfarin, cephalosporins, orlistat

Hypocalcemia symtpoms

osteoporosis, convulsion, arrythmia

Hypercalcemia symptoms

calcification of tissue, kidney stones