Vitamins are manufactured within plants and depend to some degree on the health and vigor of the plant. The controlling factors are the varieties and the conditions under which the plants are grown. Cultivated plants depend almost entirely on chemical fertilizers. Seaweeds are supplied with almost unlimited elements to feed on. Botanicals growing in the wild generally thrive only in virgin soils, or in soils that can provide the nutrients they need. When a soil becomes depleted, these botanicals move on, (via suckers, creepers, seeds, etc) or are eventually crowded out by neighboring plants.
Plant vitamins are far easier to digest than vitamins and minerals of fish or animal origin.
Listed below are some sources of these vitamins and minerals from botanicals/plants. This is only a sampling of plants, as there are too many to list here but these give you a general idea:
VITAMIN A: Needed for night vision and functioning of cells of skin and mucous membranes. Vitamin A is stored in the body, but under stressful conditions or strain, a surplus is rapidly dissipated.
VITAMIN B1 (Thiamine): Needed for growth and maintaining normal appetite.
Botanical Sources--Bladderwrack; Dulse; Fenugreek; Kelp; Okra; and Wheat Germ.
VITAMIN B2 (Riboflavin): Needed for normal growth of children. Good nutrition of adults.
Botanical Sources--Bladderwrack; Dulse; Fenugreek; Kelp; and Saffron.
VITAMIN B12: Essential for normal development of red blood cells. B12 also acts as a growth factor for children and helps put weight on under-weight children.
Botanical Sources--Alfalfa; Bladderwrack; Dulse; and Kelp.
VITAMIN C: Needed for healthy teeth and gums; prevents scurvy. Vitamin C is destroyed by heat, cooking, low temperatures, and oxidation. This vitamin is not stored in the body; a fresh supply must be provided daily.
Botanical Sources--Buffalo Berry; Burdock seed; Capsicum; Coltsfoot; Elder Berries; Marigold; Oregano; Paprika; Parsley herb; Rose Hips; and Watercress.
VITAMIN D: Needed for building and keeping good bones and teeth. Prevents rickets. A limited amount is stored in the body.
Botanical Sources--Annato seed; Watercress; and Wheat Germ.
VITAMIN E: Abundant in many plants' seeds. The need for Vitamin E has not been fully established, but is essential for full and proper nutrition.