A recently conducted study has suggested that nearly 50% of Americans above the age of 60 have low level of vitamin D. the study suggested that older people should increase their intake of Vitamin D as a deficiency of it puts them at greater risk for Alzheimer's disease.

A US Preventive Services Task Force report found that in 2014 there were lesser harms from treating vitamin D deficiency, but there was no proof that could say that there are any benefits for 'psychosocial or physical functioning'.

Joshua Miller, professor and chair of the Department of Nutritional Sciences at Rutgers University, said, "Independent of race or ethnicity, cognitive abilities and host of other risk factors, vitamin D insufficiency was associated with significantly faster declines in both episodic memory and executive function performance".

They noted that on average, people with low vitamin D declined two to three times as fast as those with adequate vitamin D. During the researchers nearly 00 racially and ethnically different men and women in Northern California were studied.

These participants were parts of a longitudinal research at the Alzheimer's disease Center in Sacramento, California. Half of the participants were Caucasian and 50% were African-American or Hispanic.

The study revealed that people who are African-American or Hispanic had lower levels of vitamin D than white people.

Miller said so far there have been no serious researches to find out if taking vitamin D could slow down or prevent memory loss.

Vitamin D is crucial as it maintains bone health, its direct sources includes sun exposure, eating eggs yolks, cheese and fish oil.