To evaluate the effectiveness and safety of vitamin supplementation in women prior to conception, periconceptionally and in early pregnancy on the risk of spontaneous miscarriage. 2. How studies were identified.

Vitamin A deficiency results from a dietary intake of vitamin A that is inadequate to satisfy physiological needs. It may be exacerbated by high rates of infection, especially diarrhoea and measles. It is common in developing countries, but rarely seen in developed countries.

2014年9月24日 · This document provides users of the Vitamin and Mineral Nutrition Information System (VMNIS) guidance about the use of serum (or plasma) folate and red blood cell folate to assess the folate status in different populations.