The liver is the primary storage organ for vitamin A (retinol), storing over 80-90% of the body's reserves, and it actively converts circulating provitamin A carotenoids (such as $\beta$-carotene) to retinol.

Human nutritional vitamin deficiency disorders:

• Vitamin A deficiency leads to night blindness (nyctalopia) and xerophthalmia.
• Vitamin B1 (thiamine) deficiency causes beriberi.
• Vitamin C (ascorbic acid) deficiency impairs prolyl hydroxylase and collagen synthesis, leading to scurvy (spongy bleeding gums, petechial hemorrhages, delayed wound healing).
• Vitamin D deficiency leads to rickets in children and osteomalacia in adults.

Nutritional chemistry of grain pulses:

• Biotin is vitamin B7, an essential micronutrient.
• Niacin is vitamin B3, an essential micronutrient.
• Pantothenic acid is vitamin B5, an essential micronutrient.
• Phytic acid (myo-inositol 1,2,3,4,5,6-hexakisphosphate) is a major anti-nutritional factor stored in grain pulses and cereals that strongly chelates essential polyvalent mineral cations (iron, zinc, calcium, magnesium), preventing their intestinal absorption.

Calculation of energy value (Atwater general factors):

• In $200\text{ g}$ food:
  Fat content: $5\% \times 200\text{ g} = 10\text{ g}$.
  Protein content: $25\% \times 200\text{ g} = 50\text{ g}$.
  Carbohydrate content: $68\% \times 200\text{ g} = 136\text{ g}$.
• Energy contribution by macronutrients:
  Energy from Fat: $10\text{ g} \times 9\text{ kcal/g} = 90\text{ kcal}$.
  Energy from Protein: $50\text{ g} \times 4\text{ kcal/g} = 200\text{ kcal}$.
  Energy from Carbohydrate: $136\text{ g} \times 4\text{ kcal/g} = 544\text{ kcal}$.
• Total energy intake:
  $\text{Total Calories} = 90 + 200 + 544 = 834\text{ kcal}$ ($834\text{ Cal}$).