维生素A&D-营养补充

Vitamin A Vitamin A can be found in various forms: retinol, the form of vitamin A absorbed when eating animal food sources, is a yellow, fat-soluble, vitamin with importance in vision and bone growth. Since the alcohol form is unstable, the vitamin is usually produced and administered in a form of retinyl acetate or palmitate. other retinoids, a class of chemical compounds that are related chemically to vitamin A, are used in medicine. Key Functions of Vitamin A Vitamin A is essential for: Vision Gene Transcription Immune Function Embryonic Development and Reproduction Bone Metabolism Haematopoiesis Skin Health Reducing Risk of Heart Disease and Cancer Antioxidant Activity It performs a variety of important functions: Beta carotene is a powerful antioxidant that neutralizes free radicals - molecules that damage healthy cells - and increases the risk of accelerating the aging process and/or health conditions. Vitamin A promotes the growth of strong teeth and bones. Fat is used to build new cells and is critical for normal brain development and nerve function. Vitamin A is essential for the formation of visual purple, a pigment that allows you to see in dim light Recommended Dietary Usage Infants (AI) - (0-6 months) - Male 400 (1,333 IU), Female 400 (1,333 IU) Infants (AI) - (7-12 months) - Male 500 (1,667 IU), Female 500 (1,667 IU) Children - (1-3 years) - Male 300 (1,000 IU), Female 300 (1,000 IU) Children - (4-8 years) - Male 400 (1,333 IU), Female 400 (1,333 IU) Children - (9-13 years) - Male 600 (2,000 IU), Female 600 (2,000 IU) Adolescents - (14-18 years) - Male 900 (3,000 IU), Female 700 (2,333 IU) Adults - (19 years and older) - Male 900 (3,000 IU), Female 700 (2,333 IU) Pregnancy - (18 years and younger) - 750 (2,500 IU) Pregnancy - (19 years and older) - 770 (2,567 IU) Breast-feeding - (18 years and younger) - 1,200 (4,000 IU) Breast-feeding - (19 years and older) - 1,300 (4,333 IU) Vitamin D Adequate intake levels of vitamin D have been established by the Food and Nutrition Board at the Institute of Medicine of The National Academies (formerly National Academy of Sciences). These intake levels are based only on age (i.e., they are the same regardless of weight, gender, pregnancy, or lactation).Birth to 50 years, 5µg (200 IU)51–70 years, 10µg (400 IU)71+ years, 15µg (600 IU)Natural sourcesNatural sources of vitamin D include: