Vitamin A: Functions and Deficiencies

Vitamin A Deficiency

• Bitot spots are triangular, frequently bilateral, and present on the bulbar conjunctiva, caused by keratinization of the conjunctival epithelium.
• In vitamin A deficiency, there is squamous metaplasia of the conjunctival epithelium, resulting in a dry, scaly patch with a foamy appearance.

Conjunctival Abnormalities

• Deposition of calcium in the conjunctiva is termed conjunctival concretions, usually occurring over the palpebral conjunctiva in chronic inflammatory conditions of the eye.
• Scarring of the conjunctiva is seen in chlamydial infection of the eye.
• Excessive growth of conjunctival tissue is seen in pterygium of the eye.

Breastfeeding

• Inadequate breastfeeding indicators in an infant:
  • Weight loss >7-10% of birth weight
  • Lethargy (sleeping longer than 2-3 hours)
  • Delayed stooling (less than 4 times/day)
  • Decreased urine output (urinating less than 5-7 times/day)
  • Hypernatremic dehydration
  • Inconsolable crying and increased hunger
• Breastfed neonates usually feed 8-12 times a day, with a minimum of 8 times per day, and should be breastfed on demand.
• The Baby-friendly Hospital Initiative recommends rooming-in (allowing mothers and infants to remain together 24 hours/day).

Vitamin A and Fat-Soluble Vitamins

• All-trans retinoic acid is the most bioactive form of vitamin A, required for cell differentiation and transcription regulation.
• 11-cis retinal is required for vision.
• Protein-energy malnutrition can cause vitamin A deficiency due to impaired synthesis of retinol binding protein (RBP).
• Hypervitaminosis A causes headache, vomiting, desquamation of the skin, and hyperostosis of long bones.
• Vitamin E is the most important antioxidant in the body, preventing free radical injury.

Breast Milk and Storage

• Breast milk stored in the refrigerator should be used within 24 hours.
• Refrigerated or frozen milk should be thawed rapidly by holding under running tepid water and used completely within 24 hours after thawing.
• Milk should never be microwaved.
• Expressed breast milk can be stored for:
  • 6 hours at room temperature
  • 24 hours in the refrigerator
  • 3 months when frozen

Human Milk vs Cow's Milk

• Lactose is present in a higher percentage in human milk compared to cow's milk.

World Breastfeeding Week

• The theme for 2020 is "Support Breastfeeding for a healthier planet, Covid-19 is an opportunity to strengthen action on breastfeeding"
• The week aims to highlight the benefits of breastfeeding for both babies and maternal health.

Baby-Friendly Hospital Initiative

• Ten steps to successful breastfeeding (Revised 2018) include:
  • Complying with the International Code of Marketing of Breast-milk Substitutes
  • Having a written infant feeding policy
  • Establishing ongoing monitoring and data-management systems
  • Ensuring staff has sufficient knowledge, competence, and skills to support breastfeeding
  • Discussing the importance and management of breastfeeding with pregnant women and their families
  • Facilitating immediate and uninterrupted skin-to-skin contact and supporting mothers to initiate breastfeeding as soon as possible after birth
  • Supporting mothers to initiate and maintain breastfeeding and manage common difficulties
  • Not providing breastfed newborns any food or fluids other than breast milk, unless medically indicated
  • Enabling mothers and their infants to remain together and to practice rooming-in 24 hours a day