as "deficient". 22% of individuals of European ancestry had 25(OH)D levels less than the 40 nmol/L cutoff, comparable to the values observed in previous studies (40nmol/L is 15 ng/mL). 78% of individuals of East Asian ancestry and 77% of individuals of South Asian ancestry had 25(OH)D concentrations lower than 40 nmol/L. The East Asians in the Toronto sample had low 25(OH)D levels when compared to whites. In a Chinese population at particular risk for esophageal cancer and with the high serum 25(OH)D concentrations have a significantly increased risk of the precursor lesion. Studies on the South Asian population uniformly point to low 25(OH)D levels, despite abundant sunshine. Rural men around Delhi average 44 nmol/L. Healthy Indians seem have low 25(OH)D levels which are not very different from healthy South Asians living in Canada. Measuring melanin content to assess skin pigmentation showed an inverse relationship with serum 25(OH)D. The uniform occurrence of very low serum 25(OH)D in Indians living in India and Chinese in China does not support the hypothesis that the low levels seen in the more pigmented are due to lack of synthesis from the sun at higher latitudes. Premature aging Complex regulatory mechanisms control metabolism. Recent epidemiologic evidence suggests that there is a narrow range of vitamin D levels in which vascular function is optimized. Animal research suggests that both excess and deficiency of vitamin D appears to cause abnormal functioning and premature aging. Case reports In 2022, a man suffered from severe Vitamin D toxicity for three months. Use as rodenticide Vitamin D is also used as a rodenticide. Rats and mice that consume the bait develop vitamin D overdose and die from hypercalcemia. Strengths used in acute baits are 0.075% (3,000,000 IU/g) for D3 and 0.01% (4,000,000 IU/g) for D2. Death happens several days after a single intake. See also Hypervitaminosis Vitamin D and neurology Vitamin D deficiency References External links Vitamin D Effects of external causes Hypervitaminosis