Ilmu gizi dasar Afriyana Siregar 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 plays important roles in many process throughout the body. Probably the most well understood function that Vitamin D has is in the absorption of calcium from the small intestine. When vitamin D is inadequate calcium from the diet is poorly absorbed. Another well characterized and important role of vitamin D is to maintain appropriate levels of calcium and phosphate in the blood to ensure proper bone formation, mineralization, growth, and repair. Vitamin D has other roles that have been less well characterized. It is thought to improve muscle strength and immune function and reduce inflammation.

Vitamin D Deficiency At risk populations Breastfed infants Older adults People with limited sun exposure Darker skin pigments Certain religious groups People at risk for vitamin D deficiency include breastfed infants, older adults, people with limited sun exposure, people with dark skin, and people with fat malabsorption. People age 50 and older are at increased risk of developing vitamin D deficiency because as they age the skin looses its ability to synthesize vitamin D as efficiently and the kidneys also convert less to its active form. People living in the northern latitudes, homebound individuals, and women who wear long robes and head coverings for religious reasons may also not obtain adequate levels of vitamin D from sunlight. People with darker skin have more pigment melanin which reduces the skin’s ability to produce vitamin D after sun exposure.

Vitamin D Related Diseases Rickets Osteomalacia Osteoporosis Prolonged inadequate intake of vitamin D will lead to impaired bone metabolism. In children, under mineralization of bone causes soft and deformed bones and can lead to the condition known as rickets. Rickets is rare in the US today, but was fairly common as recently as 100 years ago. When children developed rickets, their legs were too weak to hold their weight, resulting in bowed legs, which often persisted into adulthood. Osteomalacia is the adult form of rickets, and leads to impaired mobility and bone fractures. And osteoporosis, a condition that leads to weak and porous bones.

Vitamin D and Cancer How it prevents Promotes cellular differentiation Decreases cancer cell growth Stimulates cell deaths The exact role of vitamin D in cancer prevention is still unclear, however researchers know that vitamin D plays and integral role in cellular differentiation. Increased levels of vitamin D decrease the growth of cancer cells and stimulates cell death.

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