The pH scale indicates acidity or alkalinity. A soil with a pH number below 7 is acid, while one with a pH above 7 is alkaline. Garden plants typically grow best in neutral or slightly acid soil (pH 7 or slightly below; see illustration at left).f your soil is extremely acidic or alkaline and you need to change the level by more than one point on the pH scale, it's best to bring in a professional: he or she can both analyze test results and perform an on-site evaluation to determine whether the soil can be amended successfully and how best to go about it.
There are two different types of vitamin A. The first type, preformed vitamin A, is found in meat, poultry, fish, and dairy products. The second type, provitamin A, is found in fruits, vegetables, and other plant-based products. The most common type of provitamin A in foods and dietary supplements is beta-carotene.
Multivitamins should contain vitamin A in the form of beta-carotene, which the body converts to vitamin A. Though large doses of vitamin A are stored in the body and are toxic, beta-carotene is not toxic, though high doses (33,000â50,000 IU) may raise the risk of lung cancer in smokers. B vitamins.