1 Clean your brush and use clean water or a second color to paint inside the outline, being sure to blend with the outer color. 2  Leave the middle white. 3  For a dark center, paint it in once the flower has dried.  For a light center, paint it while the flower is still wet to blend.
Vitamin A is a group of unsaturated nutritional organic compounds that includes retinol, retinal, retinoic acid, and several provitamin A carotenoids (most notably beta-carotene). Vitamin A has multiple functions: it is important for growth and development, for the maintenance of the immune system and good vision.
Vitamin A is essential for a variety of biologic processes, many of which are related to growth, cellular differentiation and interactions of cells with each other or with the extracelluar matrix.any studies have now demonstrated that vitamin A (retinoic acid) is an important determinant of cell growth and differentiation. The classic studies of Wolbach and Howe (1925) established the necessity for vitamin A to maintain normal differentiation of tissues throughout the body.