Vitamin A Ashwini Kalantri MICRONUTRIENTS

Vitamins Essential Nutrients Types –Fat soluble – A, D, E, K –Water soluble – B group, C 2

Vitamin A Per-formed vitamin – Retinol Pro-vitamin – β-carotene 1IU = 0.3µg retinol (0.55µg of retinol palmitate) Retinol Equivalent (RE) –1µg retinol = 1 RE –1µg β–carotene = RE –1RE = IU of Vitamin A 3

Functions Normal Vision –Retinal pigmentation  vision in low light Integrity and function of glandular and epithelial tissue of Respiratory System, Urinary Tract, Skin and Eyes Skeletal Growth Anti-infective Protective against some epithelial cancers 4

Sources Animal Foods: liver, eggs, butter, cheese, milk, fish, meat Plant Foods: green leafy vegetables – spinach. Yellow and green fruits – papaya, mango, pumpkin. Roots – carrots. Fortified Foods: vanaspati, margarine, milk. Liver stores Vitamin A as retinol palmitate. Reserves for 6-9 months 5

Deficiency Xerophthalmia XNNight blindness X1AConjunctival xerosis X1BBitot spot X2Corneal xerosis X3ACorneal ulceration, less than 1/3 X3BCorneal ulceration, more than 1/3 XSCorneal scar XFXerophthalmic fundus Singh, K. "Modified classification of xerophthalmia." Indian Journal of Ophthalmology 39.3 (1991):

Deficiency Extra-ocular Folicular Hyperkeratosis Anorexia Growth retardation Mortality and morbidity due to respiratory and intestinal infections. 7

Prevention Improvement of diet Reducing the severity of the contributory factors –PEM, respiratory tract infection, diarrhea, measles. 6 monthly massive dose administration –1,00,000 IU (6 months – 1 year) –2,00,000 IU (1 year – 6 years) 8

Treatment Urgent treatment Early stages of Xerophthalmia  Massive dose of Vitamin A (2,00,000 IU) orally. Repeat after 4 weeks. All children with corneal ulcers 9

Assessment Population surveys - clinical and biochemical Per-school children (6 months – 6 years) CriteriaPrevalence in population at risk (6 Months – 6 Years) Night blindness > 1% Bitot’s spots > 0.5% Corneal xerosis/corneal ulceration/keratomalacia > 0.01% Corneal Ulcer > 0.05% Serum retinol (less than 10 µg/dl) > 5% 10 WHO TRS 672

Recommended Dietary Allowance GroupRetinol (µg)β – carotene (µg) Adults Man Women Pregnancy Lactation Infants 0 – 6 months – 12 months Children 1 – 6 years – 9 years Adolescents 10 – 17 years ICMR. “Nutrient requirement and recommended dietary allowances for Indians, A report of the expert group of the ICMR” 2010

Toxicity Retinol –Nausea, vomiting, anorexia and sleep disorders –Skin desquamation, enlarged liver, papillar odema Carotene –Colour skin and plasma, not dangerous Teratogenic effects of massive dose of vitamin A 12