A new study published in Annals of Nutrition and Metabolism found that dietary vitamin D intake was significantly and positively related to short term memory, but not declarative memory.
Short term memory is the temporary storage of information and declarative memory refers to the memory of facts and events.
Declarative memory is made up of two types of memory: semantic and episodic. Semantic memory stores general knowledge and facts, while episodic memory retains personal events.
In addition to the discovery of vitamin D receptors in the brain, the enzymes needed to convert vitamin D to its active form and degrade and remove vitamin D have also been found in the brain. Together, these indicate the ability for the brain to locally use and regulate vitamin D metabolism.
French researchers recently conducted a study to establish the relationship between vitamin D and different types of memory. They used the data of 1,990 participants, ages 35 to 60 years old, from the Supplémentation en Vitamines et Minéraux Antioxydants (SU.VI.MAX) I and II studies.
The SU.VI.MAX studies were conducted to assess the effects of daily antioxidant supplements on health outcomes such as cancer and cardiovascular disease. SU.VI.MAX I took place in 1994-1996, and SU.VI.MAX II took place in 2007-2009.
During the SU.VI.MAX I, adult participants completed bimonthly 24 hour recalls for one year for a total of six 24 hour recalls. In the SU.VI.MAX II study, episodic, semantic, and short term memory were assessed in the same participants.
For the current study, the researchers took data from both SU.VI.MAX studies to evaluate the association between the participants’ reported vitamin D intake during middle adulthood and the participants’ memory 13 years later.
The researchers did not find an association between dietary vitamin D intake and declarative memory.
They did find a significant and positive association between dietary vitamin D intake and the functioning of short term memory. This means higher dietary vitamin D intake was related to improved short term memory.
“The findings extend the presently scant knowledge about vitamin D intake and cognition,” the researchers concluded.
“From a public health viewpoint, our findings have implications for cognitive function preservation into old age given the expanding elderly population worldwide and the absence of curative treatment for dementia.