Another study finding risks from too low vitamin D levels. From Science Daily:
Lower vitamin D level in blood linked to higher premature death rate
Researchers at the University of California, San Diego School of Medicine have found that persons with lower blood levels of vitamin D were twice as likely to die prematurely as people with higher blood levels of vitamin D.
The finding, published in the June 12 issue of American Journal of Public Health, was based on a systematic review of 32 previous studies that included analyses of vitamin D, blood levels and human mortality rates. The specific variant of vitamin D assessed was 25-hydroxyvitamin D, the primary form found in blood.
This new finding is based on the association of low vitamin D with risk of premature death from all causes, not just bone diseases."
Garland said the blood level amount of vitamin D associated with about half of the death rate was 30 ng/ml. He noted that two-thirds of the U.S. population has an estimated blood vitamin D level below 30 ng/ml."This study should give the medical community and public substantial reassurance that vitamin D is safe when used in appropriate doses up to 4,000 International Units (IU) per day," said Heather Hofflich, DO, professor in the UC San Diego School of Medicine's Department of Medicine.
The average age when the blood was drawn in this study was 55 years; the average length of follow-up was nine years. The study included residents of 14 countries, including the United States, and data from 566,583 participants.