Vitamin A is necessary to support healthy eyesight and immune system functions; children who are deficient face an increased risk of blindness and death from infections such as measles and diarrhea.
Vitamin A is known to actively participate in the adipocyte metabolism.
One of its metabolites, all-trans retinoic acid, has been known to stimulate lipolysis by activating the peroxisome proliferation-activated receptor delta and retinoic acid receptor. Retinoic acid has been found in vitro to decrease preadipocyte survival time and to inhibit or promote adipose cell differentiation.
In addition, retinoic acid has been shown to inhibit the expression of leptin, resistin and uncoupling proteins (UCP) in mice and human cell culture tissues
Vitamin A concentrations were associated with high concentrations of leptin, and the same was observed in women that had low BMI, low body fat percent and low waist circumference.
Vitamin A and its metabolites have different effects on leptin expression among individuals that differ in adipose tissue and total body fat content.
Globally, 1 in 3 pre-school aged children and 1 in 6 pregnant women are vitamin A deficient due to inadequate dietary intake.
Vitamin A supplementation of children 6-59 months has been shown to be highly effective in reducing mortality from all causes in countries where vitamin A deficiency is a public health concern.