IndexAbstractMethodsMaterials and proceduresResultsDiscussion AbstractVitamin D plays a role in many important biological functions; deficits lead to poor cardiovascular health, bone mineral density, muscle mass and function, abdominal density, insulin resistance, type 1 and 2 diabetes, kidney disease, liver disease, cognitive impairment, metabolic syndrome, immune disorders, cancer and pregnancy complications. Participants with vitamin D deficiency and no serious disease were given a placebo or 3,000 IU daily of vitamin D for a year with monthly word recall tests. Participants who received the vitamin showed statistically significant improvement in word recall tests. These findings support the hypothesis that vitamin D improves memory. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essayThe International Osteoporosis Foundation defines a concentration of 0-10 ng/ml of 25-hydroxyvitamin D as a severe deficiency, 10-20 ng/ml as deficiency, 20-30 ng/ml as insufficiency, 30-80 ng/ml ml as optimal and >100 ng/ml as at risk of toxicity (Matyjaszek-Matuszek, Lenart-Lipinska, & Wozniakowska, 2015). Humans absorb 80-90% of their vitamin D from ultraviolet beta radiation from the sun. The 7-dehydrocholesterol present in the body is converted into cholecalciferol with the help of ultraviolet beta radiation. The additional 10-20% comes from the diet in the form of ergocalciferol. Supplements are also an option. These products are further synthesized in the liver, then in the kidneys, producing the steroids 20-hydroxyvitamin D and 1,25-dihydroxyvitamin D (Darwish, Zeinoun, Ghusn, Khoury, Tamim, & Khoury, 2015; Matyjaszek-Matuszek et al., 2015) . ).Vitamin D has its own receptors, which make it a hormone. Vitamin D receptors are found in neurons, glial cells, the skeletal system, enterocytes, adipose tissue, renal tubular cells, immune cells, pancreatic cells, myocytes, cardiomyocytes, endothelial cells, and some tumor cells (Darwish et al., 2015; Matyjaszek-Matuszek et al., 2015). Vitamin D is a fat-soluble transcription factor that is thought to regulate approximately 3% of the human genome. Vitamin D has long been known to play a vital role in calcium phosphate homeostasis. Recent studies have demonstrated a correlation between a wide variety of diseases and vitamin D. Vitamin D concentration is positively correlated with cardiovascular health, bone mineral density, muscle mass and function (Arabi, Awada, Ayoub, El -Hajj Fuleihan, 2006). Vitamin D concentration is negatively correlated with mortality, abdominal density, hypertension, insulin resistance, type 1 and 2 diabetes, age, kidney disease, liver disease, sunscreen use, cognitive impairment, smoking, obesity, and pollution atmospheric (Darwish et al., 2015 ; Matyjaszek-Matuszek et al., 2015). Low vitamin D has also been linked to metabolic syndrome, immune disorders and pregnancy complications. Vitamin D is a growth inhibitor for prostate, colon, breast, lung, liver, ovarian, and pancreatic cancers (Matyjaszek-Matuszek et al., 2015). Rats without functional vitamin D receptors exhibit cardiovascular disease, myocardial hypertrophy, and endothelial dysfunction (Ni, Watts, Ng, 2014). Vitamin D insufficiency is known to correlate with cognitive decline in older adults. Older adults with low vitamin D levels report greater memory loss than older adults with healthy vitamin D levels (De Neree Tot Babberich, Gourdeau, Pointel,Lemarchant, Beauchet and Annweiler, 2015). Darwish (2015) found a significant positive correlation between visuospatial memory and vitamin D concentration in people as young as 30 years old. In northern latitudes, blood vitamin D concentrations fluctuate with the seasons, highest in summer and lowest in winter. Working memory and executive functions have been shown to decrease in winter and increase in summer (Pettersen, Fontes, & Duke, 2014). Diabetic rats have poorer episodic memory and have less cholinergic transmission in their prefrontal cortices than healthy rats. Vitamin D supplementation of 500 IU/day for 10 weeks improves episodic memory and cholinergic transmission in diabetic rats (Alrefaie & Alhayani, 2015). We hypothesize that giving 3000 IU of vitamin D per day to vitamin D deficient people for one year will improve their episodic memory as demonstrated in a word recall test. Participants will have an initial level of 10-20 ng/ml of serum 25-hydroxyvitamin D in the blood, which is classified as vitamin D deficiency by the International Osteoporosis Foundation. Blood tests for vitamin D and word recall tests will be administered on a monthly basis for one year. A correlation has been demonstrated between vitamin D and memory. This longitudinal experiment will provide causal evidence showing that increased vitamin D leads to improved memory. Vitamin D is important for the functioning of the human brain and body. This study will expand our knowledge of the value of vitamin D supplements. Methods 500 participants with vitamin D deficiency (10-20 ng/ml serum 25-hydroxyvitamin D in blood) were recruited through physician practices and college campuses in Vermont with flyers asking for healthy volunteers between the ages of 20 and 40. They were paid $20 per visit to the research center. They each had English as their self-reported first language, had completed high school, and had a body mass index (kg/m²) between 18.5 and 24.99 (Quetelet & Knox, 18; “WHO:: Global Database on Body Mass Index”, n.d.). They had not smoked, taken vitamin D supplements, or taken any medications known to affect cognition in the past 3 months. Participants ranged in age from 20 to 40, with an average age of 27. Women at any stage of menopause were excluded. Participants had no history of drug or alcohol abuse, traumatic brain injury, neurological, psychiatric, or cognitive disorders. Participants were screened for depression and anxiety disorders with the Hopkins Symptoms Checklist-25 (Parloff, Kelman, & Frank, 1954), scoring less than 1.75 on the depression and anxiety sections. Participants had intelligence quotients within one standard deviation of the mean (85-115) (Terman, 1916). Participants had healthy levels of calcium and vitamin B12 in their blood. Materials and procedures Participants were randomly divided into 2 groups, a control group that took a placebo and a group that took 3000 IU of vitamin D per day for one year. Vitamin D levels and episodic memory, as demonstrated in a word recall test, were tested on the first of each month. People with unsafe vitamin D levels were excluded from the study and recommended a course of action. The blood was stored as serum at -20°C until 5 ml were analyzed with an electrochemiluminescent immunoassay for serum 1,25-dihydroxyvitamin D levels. improve their memory compared to participants taking a placebo, such as demonstrated in a word recall test. Participants in the control group remembered 61% of the words in the..