The substance named as vitamin B by the early investigators was discovered to contain a large number of vitamins. Because of the close bond between them were later collectively referred to as the B complex vitamins.
The most serious effect of the lack of vitamin A is NIGHT BLINDNESS. Night blindness is the inability of a person to adjust to the changing intensity of light. Persons suffering from night blindness cannot see in dim light especially at night.
Iodine is an important part of the hormone thyroxine. The thyroid gland, which is located in the neck, secretes this hormone. Thyroxine regulates some important metabolic processes related to growth and oxidation.
Calcium and phosphorus make strong bones and teeth and vitamin D is essential for the absorption of calcium and phosphorus. Therefore, deficiency of calcium, phosphorus and vitamin D in the body leads to poor bone formation. In growing children and nursing mothers, the chances of the deficiency of calcium and phosphorus are more as their requirement of these minerals is more.