Vitamin larut lemak
Ilmu gizi dasar
Afriyana Siregar
Vitamin
adalah zat-zat organik
(mikronutrien)
yang
diperlukan tubuh dalam
jumlah yang sangat
kecil. Zat-zat tersebut
sangat
dibutuhkan
untuk pertumbuhan dan
pemeliharaan
tubuh.
Zat-zat ini tidak dapat
dibuat oleh tubuh, jadi
harus ada di dalam
makanan yang kita
makan.
Vitamin dibagi menjadi 2 yaitu :
• Vitamin larut dalam air : vitamin C dan vitamin
B
• Vitamin larut dalam lemak : vitamin A, D, E, K
Fat Soluble Vitamins
•
•
•
•
Associated with fat absorption
Needed in small amounts
Stored in fatty tissues
Excess intake has toxic consequences
Vitamin A
(Preformed and Provitamin)
• Preformed: Three preformed compounds that
are metabolically active and found in animal
products
– retinol – alcohol form
– retinal or retinaldehyde – aldehyde form
– retinoic acid – acid form
• Provitamin: Carotenoids (b-carotene) and
cryptoxanthin can yield retinoids when
metabolized in the body
• These are from plant sources
SATUAN VIT A & EKIVALENNYA
1 RE = 1,0 UG RETINOL
= 6,0 UG BETA KAROTEN
= 3,3 SI (SATUAN INTERNASIONAL)
RETINOL
= 9,9 SI BETA-KAROTEN
Vitamin A
• Vitamin A atau retinol
Macam vitamin A: A1 atau retinol
A2 (dehidroretinol)
Dalam tumbuh-tumbuhan terdpt senyawa yg
mpunyai struktur & sifat spt vit A dan di sebut
KAROTEN, dlm tubuh dpt diubah mjd vit A
Vitamin A
• Fungsi: - struktur dan fungsi normal mata,
mempertahankan diferensiasi jaringan epithelial,
pertumbuhan sel dan ketahanan terhadap infeksi,
menjaga ikan berada dalam kondisi prima untuk
memijah
• Defisiensi: - pertumbuhan terhambat, gangguan
penglihatan, GG IMUNITAS, Difrensiasi sel,
antioksidan (kanker & jantung), k- nafsu makan
• Kebutuhan: 1000-4000 IU/kg
Kelebihan vit A
• Hal 166, sunita alt
Vitamin
• Vit D/ kalsiferol
• Vit D termsk kelompok senyawa sterol yaitu
ergosterol yg ada dlm tumbuh2an yg diubah
mjd ergokalsiferol atau vit D2 oleh UV, jk
terkena sinar UV akn diubah mjd kolekalsiferol
atau Vit D
• Rachitis atau ricketsia
Vitamin D
Also known as calciferol, 1,25-dihydroxy vitamin D (calcitriol), vitamin D3 or
cholecalciferol, vitamin D2 or ergocalciferol
Vitamin D is a nonessential nutrient that acts like a hormone in the body.
The body can make vitamin D with help from sunlight.
The plant version of vitamin D is called vitamin D2 or ergocalciferol.
The animal version of vitamin D is called vitamin D3 or cholecalciferol.
Once the vitamin enters the body it must become activated.
Activation occurs through the action of the liver and the kidneys.
© 2008 Thomson - Wadsworth
• Fungsi: - calcium homeostasis, Calcium
binding protein, Mobilisasi, transport,
absorpsi dan penggunaan Ca dan P
• Defisiensi: - penurunan berat badan, rendah
Ca dan P
• Kebutuhan: 500-2400 IU/kg
Sumber vit D
Vitamin D Functions
• Many uses in the body
– Promotes absorption of calcium from the small
intestine
– Maintain blood levels of calcium and phosphate
for bone formation, mineralization, growth, and
repair
– Improves muscle strength and immune function
– Reduces inflammation
Vitamin D Deficiency
At risk populations
– Breastfed infants
– Older adults
– People with limited sun exposure
– Darker skin pigments
– Certain religious groups
Vitamin D Related Diseases
– Rickets
– Osteomalacia
– Osteoporosis
Vitamin D and Cancer
How it prevents
– Promotes cellular differentiation
– Decreases cancer cell growth
– Stimulates cell deaths
• Vit E/ tokoferol/
• Kuning muda hingga kcoklatan
• Alfa, beta, gamma, delta tokoferol &
tokotreinol
FUNCTIONS
• The main function of vitamin E is anti
oxidant. It intercepts free radicals &
prevents destruction of cell membrane.
• It protects the fat in LDL from oxidation.
• It inhibits platelets aggregation.
• It enhances vasodilatation.
• It inhibits the activity of protein kinase C.
• Defisiensi:
anemia
dan
pertumbuhan
terhambat
• Kebutuhan: 50 - 100 IU/kg
Vitamin E deficiency
•Severe vitamin E deficiency causes:
Neurological symptoms (impaired
coordination) & muscle weakness.
Increased risk of cardiovascular diseases
Hemolytic anemia in children
RISK FACTORS
Severe PEM
Genetics defects affecting the transfer
protein of a-tocopherol
 Fat malabsorption syndrome
TOXICITY
Excess vitamin E may cause:
 Impaired blood clotting leading to increased
risk of bleeding in some persons.
It is recommended that vitamin E supplements
to be stopped one month before elective surgery.
Sumber vitamin E
Sumber vit E
VITAMIN K
The K is derived from the German word
Koagulation.
There are 2 naturally occurring forms of vitamin K.
Plants synthesize phylloquinone (vitamin K1) &
bacteria synthesize menaquinone-3 (vit K2).
Menaquinone-4 is produced in animals from vit
K1, but its function is yet to be discovered.
Vitamin K
• Fungsi: Transport electron, Phosphorilasi
oxidative, Cofactor dalam proses pembekuan
darah
• Kebutuhan: 10 IU/kg
Sumber vit K
Table 10-4, p. 361
Deficiency: rare in adults; newborns, chronic antibiotic administration, and
malabsorption can result in deficiency
Bleeding episodes
Osteoporosis
Toxicity: none known