Despite its name, vitamin D is not a vitamin, but a steroid hormone made in the skin, (from cholesterol). The normal range is pretty wide, from 30 to 100, and it’s better to work up to the higher levels than maintain at the lower levels. It’s usually pretty easy to get to “normal” levels by taking up to 50,000 units of vitamin D3 a week for up to 8 weeks and then maintain at 1000 to 5,000 units daily.
57% of patients in once study were judged to be vitamin D deficient, including 37% who consumed more than the recommended amount of vitamin D (at least 800 IU/ day). Although vitamin D can be obtained through the diet, most foods contain very small amounts, so humans are dependent on skin production to maintain normal levels ( or, with the addition of daily supplements.)
Vitamin D deficiency is important to understand in age-related morbidities.
Meta-analysis of double-blind randomized trials showed that vitamin D reduced the risk of falling by 22%.
Low Vitamin D levels play a role in bladder incontinence, because there is poorer coordination of the muscles used to control urination. Low levels also play a role in age-related macular degeneration as well asl cognitive decline.
The lower the vitamin D, the greater the incidence of sarcopenia, or bone loss. Men and women with baseline levels less than 25 no LVH/L were more than twice as likely to develop sarcopenia.
Increasing the levels of serum vitamin D regardless of age, may reduce the risk of breast cancer. Vitamin D level of 35 ng/ml has associated with a 20% reduction in the risk of breast cancer. In another study, average levels of 52 ng/ml had 50% lower risk of breast cancer than those with serum vitamin D of less than 13 ng/ml. Vitamin D intake of 2,000IU/day has been associated with vitamin D levels of 32 ng/ml. The higher level noted above corresponded to an intake of 4,000 IU of vitamin D per day.
Vitamin D may provide greater health benefits than previously thought, benefits that include not only improved bone health, but other effects as well. Increased vitamin D levels may decrease the risk of cancer, especially that related to colorectal adenomas. Elderly adults may even benefit from higher doses such as 2000 IU to 5000 IU daily. Vitamin D levels of 82 nmol/L and higher were also associated with a 50% lower risk of developing colorectal cancer. Some researchers are advocating even higher doses, up to 10,000 IU per day.
Lower levels of Vitamin D are associated with a higher risk of heart attack in a graded manner. High levels of vitamin D among middle-age, and elderly populations are associated with a substantial decrease in cardiovascular disease, type 2 diabetes and metabolic syndrome.
Vitamin D has been traditionally related to bone metabolism, although several studies in the last decade have suggested its role in muscle strength and falls, cardiovascular and neurological disease, malignancies, autoimmune diseases and infections. Vitamin D appears to be a hormone with several actions and is fundamental for many biological systems including bone, skeletal muscle, brain and heart. It helps to maintain physical strength in the elderly and is protective against falls.
Additionally, a study demonstrated that women with moderate to severe depression had substantial improvement in their symptoms of depression after they received treatment for Vitamin D deficiency. Both the presence and severity of depression were associated with decreased serum levels of vitamin D and increased levels of parathyroid hormone in older patients.
In a paper called Vitamin D for cancer prevention: Global Perspective, higher levels of vitamin D were associated with substantially lower incidence rates of colon, breast, ovarian, renal, pancreatic, aggressive prostate and other cancers. It was projected that raising the minimum year- around levels to 40 to 60 ng/ml would prevent approximately 58,000 new cases of breast cancer and 49,000 new cases of colorectal cancer each year, and three fourths of deaths from these diseases in the United States and Canada.
I hope that this little essay helps you understand and appreciate further the role of vitamin D.