***How much vitami D is enough?

A growing body of evidence indicates that adequate vitami
D status is needed to prevent osteoporosis, muscle weakness and pain, certain types of cancer, and other disorders. The RDA for vitami
D was originally set at 400 IU per day for children. This was based on nothing more than the fact that that amount is present in a teaspoon of cod liver oil, which had long been considered safe and effective for preventing rickets. The basis for adult recommendations was even less well defined.
In a recently reviewed study researchers analyzed the relationship between blood concentrations of vitami
D and bone mineral density, lower-extremity function, dental health, and risk of falls, fractures, and colorectal cancer. In most people, optimal concentrations could not be reached with the currently recommended dosages of 200 IU of vitami
D per day for younger adults and 600 IU vitami
D per day for older adults. The study confirmed that, for bone health in younger adults and for older adults, an increase in the currently recommended intake of vitami
D is warranted. The study suggests an intake for all adults of at least 1,000 IU/day is needed to bring vitami
D concentrations up to optimal levels in at least 50% of the population.
Studies over the past 10 years have shown that vitami
D deficiency is very common, approaching 40% in some populations. The results of this new study suggest that significantly more vitami
D than the amount currently being recommended is needed to promote optimal health.
The Food and Nutrition Board has established a safe upper limit of 2,000 IU/day for vitami
D intake. People who stay below that level are unlikely to experience any adverse effects over the long term. However, 2,000 IU/day of vitami
D could conceivably cause adverse effects in people who have substantial amounts of sunlight exposure.

From research presented by Alan Gaby M.D., literature review and commentary. Dr. Gaby’s references noted were: Bischoff-Ferrari HA, et al. Estimation of optimal serum concentrations of 25-hydroxyvitami
D for multiple health outcomes. Am J Clin Nutr. 2006;84:18-28. (Am J Clin Nutr. 2004; 79:717-726)

Patrick Heffe
anr
Contributor, IVL Healthwatch