Until recently, it was commonly believed that a daily dose of sunshine guarantees adequate vitamin D levels. Well, not anymore.

The latest studies are showing that most people, and especially the elderly, are vitamin D deficient. Although our bodies manufacture vitamin D when exposed to sunshine, how much depends on where you live and how much exposure you get. In fact, people who live in areas where the sun rarely shines make no vitamin D at all, and must depend entirely on dietary supplements and vitamin D-fortified foods. During the winter, almost everyone who lives in the northern hemisphere can benefit from vitamin D supplements to boost immunity, and to stave off the blues and other health complaints, including osteoporosis.

Vitamin D deficiency is especially common in the elderly. Researchers have found a correlation between vitamin D deficiency and low mood, depression and worse cognitive performance in older adults. In a recent study, 1618 patients who averaged 73.8 years old were tested for vitamin D deficiency. Those with severe vitamin D deficiency were twice as likely to suffer from depression.1

Another study of a cross-section of 80 older adults, 40 with mild Alzheimer’s disease and 40 healthy adults, found that vitamin D deficiency was associated with low mood and impairment on two of four measures of cognitive performance. 58% of the participants had abnormally low vitamin D levels. After adjusting for age, race, gender, and the season in which vitamin D levels were studied, researchers correlated vitamin D deficiency with an active mood disorder. The deficiency was also related to a worse performance on the cognitive performance test called Short Blessed Test (SBY). There was no difference in performance on the Mini-Mental State Exam (MMSE). 2

Why is Vitamin D important?
Vitamin D refers to two biologically inactive precursors – D3, also known as cholecalciferol, and D2, also known as ergocalciferol. Vitamin D3 is produced in the skin on exposure to UVB radiation (290 to 320 nm), and is more bioactive.Vitamin D deficiency may exacerbate osteopenia, osteoporosis, muscle weakness, fractures, some cancers, autoimmune diseases, infectious diseases and cardiovascular disease. There is also some evidence that vitamin D may reduce the incidence of several types of cancer and type-1 diabetes, and the onset of dementia.

Whether you are a caregiver, healthy adult, or someone with mild dementia, it’s important that you make sure your intake of vitamin D is adequate.

How much do you need?
The current recommended intakes for vitamin D are 600 IU for adults 19 to 70, and 800 IUs for 71 years and older. But Michael F. Holick, PhD, M.D., the world’s leading expert on vitamin D, recommends taking a minimum of 1,000 IUs of supplemental vitamin D daily for children and adults. 3 Other researchers recommend taking up to 8,000 IUs per day. If you want to know for sure what your blood serum levels of vitamin D are, ask your physician to test you.

References

1. Lapid MI, Cha SS, Takahashi PY.Clin Interv Aging. 2013;8:509-14. doi: 10.2147/CIA.S42838. Epub 2013 May 3.
   2. Wilkins CH, Sheline YI, Roe CM, Birge SJ, Morris JC. Vitamin D deficiency is associated with low mood and worse cognitive performance in older adults.Am J Geriatr Psychiatry. 2006 Dec;14(12):1032-40.
   3. Wiiliam B. Great, Ph.D, and Michael F. Holick, Ph.D, M.D. Benefits and Requirements of Vitamin D for Optimal Health: A Review, Alternative Medicine Review, Volume 10, Number 2, 2005.