Different from former RDAs, phosphorus values in the report are not derived in relation to calcium. The values recommended are considered sufficient to support normal bone growth and metabolism at various ages. Magnesium works with many enzymes to regulate body temperature, allow nerves and muscles to contract, and synthesize proteins. Although some researchers have argued that magnesium recommendations should be based on relationships with the risk of cardiovascular disease, the report does not find enough data available at this time to do so. The levels recommended, although somewhat higher, do not differ substantially from the 1989 RDAs but are higher than current Canadian recommendations.
Vitamin D used by the body comes mostly through exposure to the sun.
Vitamin D deficiency can exacerbate osteoporosis and other bone problems in adults. Dietary intake of vitamin D is unnecessary for people who spend adequate amounts of time in the sun. The levels recommended in the report are estimated to provide enough vitamin D even for individuals with limited sun exposure. The AIs of 10 micrograms from age 51 to 70 and 1 micrograms over age 70 are higher than their 1989 counterparts. Fluoride is found naturally in some community water systems, and is added to water in other areas to reduce dental decay.