Vitamin D is a fat-soluble vitamin that is naturally present in very few foods. It helps fight against cancer, improves physical performance, prevents osteoporosis, helps promote brain function and reduces depression. Deficiency of this vitamin may lead to brain disorders like Parkinson’s and Alzheimer’s.
Vitamin D Two Part Series
- Vitamin D benefits 1-19 (Part 1)
- Vitamin D benefits 20-35 (Part 2)
Vitamin D, also known as the “sunshine vitamin”, is an essential fat-soluble vitamin.
It can either be obtained in the diet, through food and dietary supplements, or synthesized in the skin upon exposure to sunlight (R).
Vitamin D plays a role in calcium and phosphorus balance important in bone health, and nerve and muscle activity.
It plays a potential role in prevention and therapy of cancer and chronic conditions such as autoimmune disorders, cardiovascular disease, and infections (R).
Health Benefits of Vitamin D
1) Vitamin D is Crucial to Bone Health
It promotes calcium and phosphorus absorption from the gut, calcium reabsorption in the kidney, and calcium mobilization in bone (R).
Vitamin D is needed for bone growth and formation by bone cells.
2) Vitamin D Prevents Rickets and Osteomalacia
Rickets is characterized by a delay in the mineralization of growth cartilage.
Maternal vitamin deficiency can affect skeletal development of fetuses.
In a study of 424 pregnant women, mothers with vitamin D deficiency were more likely to have fetuses with femoral bones that had rachitic features (R).
Adults with osteomalacia may experience global bone discomfort, and muscle aches and weakness (R).
Osteomalacia and rickets attributable to vitamin deficiency are preventable with adequate nutritional intake of this vitamin.
Varying doses and treatment regimes have been described with the aim is to achieve a blood level between 20 and 50 ng/mL (R).
3) Vitamin D Prevents Osteoporosis and Fractures
Studies show that in adults aged 50 years or older, vitamin D supplementation in combination with calcium has beneficial effects on bone mineral density, osteoporotic fractures and falls without evidence of harm (R, R2, R3).
In elderly women that were given 1200 mg of calcium and 800 IU of vitamin D3 daily for 3 years, the risk of hip fracture was reduced by 43%.
The risk of fracture was reduced by 32% (R).
However, annual administration of high doses of vitamin D (500 000 IU) resulted in an increased risk of falls and fractures in older community-dwelling women (R).
4) Vitamin D Can Improve Physical Performance
Clinical evidence suggests that vitamin D plays a role in muscle metabolism and function (R).
Hence the function of the muscle is either of an indirect nature or does not involve the known receptor (R).
Supplementation with this vitamin has been shown to improve muscle strength, balance, and physical performance.
Supplementation also reduced the risk of falls by more than 20% (R).
Vitamin D may increase muscle strength by improving atrophy of type II muscle fibers, which may lead to decreased falls and hip fractures (R).
Insufficiency of this vitamin is associated with increased fat infiltration in the muscles of healthy young women (R).
It may improve athletic performance in vitamin D-deficient athletes.
5) Vitamin D May Protect Against Cancer
The majority of studies found that sufficient vitamin D protects against cancer and risk of dying (R).
Vitamin D and its byproducts inhibit the spreading of cancer and cancer cell growth. It also induces cancer cell death.
Intake of 2000 IU/day of Vitamin D is associated with a reduction by 50% in the incidence of breast cancer (R).
Some studies did not show an association between higher vitamin D intakes and lower breast cancer risk in postmenopausal women.
Daily intake of 1000-2000 IU/day of this vitamin could reduce the incidence of colorectal cancer by 50% (R).
Higher intakes of vitamin D were associated with lower risks for pancreatic cancer.
Doses of 600 IU/d or more of this vitamin lowered the risk of pancreatic cancer by 41% (R).
It has been shown that low vitamin D levels are present in ovarian cancer patients, and are associated with lower overall survival rate (R).
Ultraviolet B (UVB) radiation is associated with lower risk of ovarian cancer (R).
6) Vitamin D is Beneficial for Brain Development and Function
Studies indicate that this vitamin is important for brain development.
It may protect brain cells through detoxification pathways (production of antioxidant glutathione, inhibition of nitric oxide).
Epidemiological studies show that low concentrations of vitamin D are associated with:
- diagnosis of dementia and Alzheimer’s disease (R).
- higher rates of psychotic experiences and schizophrenia (R, R2, R3).
7) Vitamin D Improves Cognitive Functions
While, other studies suggest that blood levels of this vitamin do not influence cognitive or emotional functioning.
8) Vitamin D Reduces Depression
Deficiency of vitamin D was associated with an 8–14% increase in the prevalence of depression.
Also, some studies showed that supplementation of this vitamin neither worsened nor improved depressive symptoms.
In elderly postmenopausal women, there was no effect of hormone therapy and vitamin D either individually or in combination on depression (R).
9) Vitamin D Reduces Risk of Parkinson’s Disease
Vitamin D deficiency may contribute to the development of Parkinson’s disease.
Higher vitamin D blood levels are associated with reduced risk of developing Parkinson’s disease.
Individuals with a blood vitamin concentration of at least 50 nmol/l had a 65% lower risk than those with values under 25 nmol/l (R).
10) Vitamin D Plays a Role in Alzheimer’s Disease
Vitamin D deficiency is prevalent in Alzheimer’s disease and dementia patients.
Blood levels of this vitamin less than 50 nmol/L were associated with a higher risk of Alzheimer’s disease and dementia (R).
11) Vitamin D is Beneficial in Multiple Sclerosis
Higher vitamin D blood levels protect from developing multiple sclerosis.
Also, higher vitamin D levels were associated with a reduced worsening and recurrence of multiple sclerosis symptoms.
Optimal blood concentrations of this vitamin may decrease disease-related complications, including increased bone degradation, fractures, and muscle weakness (R).
Increased sun exposure during ages 6–15 years is associated with a decreased risk of multiple sclerosis.
Multiple sclerosis occurs less often if this vitamin abundant, as in sunny climates, high altitudes, and areas with dietary rich in fish oils (R).
Vitamin D has anti-inflammatory action in multiple sclerosis.
12) Vitamin D Improves Sleep Quality
Vitamin D could be important for sleep disorders (R).
Higher concentrations of this vitamin were associated with better maintenance of sleep (R).
In National Health and Nutrition Examination Survey (NHANES) study, lower vitamin levels were associated with shorter sleep duration (R).
Some studies suggest improved sleep quality with vitamin D supplementation.
Studies have reported a high prevalence of this vitamin deficiency in obstructive sleep apnea syndrome.
This is a widespread disorder characterized by episodes of breathing cessation due to upper airway tract obstruction during sleep (R).
More studies are needed to prove this relationship between sleep quality and vitamin D supplementation.
13) Vitamin D Reduces the Risk of Cardiovascular Disease
Study showed that this vitamin supplementation or UVB irradiation may lower blood pressure, improve blood pressure control, and regress heart enlargement (R).
However, some studies show opposite findings.
Daily supplementation with 800 IU vitamin D for 12 weeks did not impact blood pressure, renin and fat concentrations, markers of cardiovascular disease (R).
Study of healthy postmenopausal women, given 400 IU/day or 1000 IU/day vitamin D for a period of 1 year, showed no significant benefit to heart disease risk (R).
14) Vitamin D Reduces Blood Pressure
Blood pressure was significantly decreased after 6 weeks of therapy in individuals receiving UVB therapy (R).
This vitamin decreases activity of the renin-angiotensin system.
In vitamin D deficient elderly women, there was a 9% decrease in systolic blood pressure (by 13 mmHg) with supplemental vitamin D and calcium compared with calcium alone (R).
Studies including more than 1800 patients found an increased risk of high blood pressure in those with vitamin D level <50 nmol/L compared to those >75 nmol/L (R).
15) Vitamin D May Decrease the Risk of Type 1 and Type 2 Diabetes
Vitamin D plays a role in insulin production and secretion from pancreatic cells (R).
A study found that an intake of 2,000 IU of this vitamin during the first year of life diminished the risk of developing type 1 diabetes (R).
The Diabetes Autoimmunity Study in the Young (DAISY) reported an increased presence of antibodies against pancreatic cells in newborns of mothers with low intake of this vitamin during pregnancy (R).
In the Women’s Health Study, an intake of 511 IU/day of vitamin D or more was associated with lower risk of type 2 diabetes (R).
It may have a role in delaying the progression to diabetes in adults at high risk of type 2 diabetes.
Supplementation was associated with improved function of pancreatic cells (R).
It also had an effect on the rise of Hb A1C (shows average blood sugar levels over a period of weeks/months) that occurs over time (R).
16) Vitamin D Prevents Obesity and Metabolic Syndrome
There is a genetic evidence that higher body mass index (BMI) leads to lower vitamin D status (R).
12 week supplementation with 25 μg of vitamin D in overweight and obese women decreased body fat mass by 7%, but did not affect body weight and waist circumference (R).
Obese African Americans are at particularly high risk for this vitamin deficiency.
Physicians should consider routine supplementation or screening of these patients for low vitamin D levels (R).
Higher blood levels of vitamin D were associated with a decrease in the prevalence of the components of metabolic syndrome (elevated blood pressure, elevated triglycerides, and reduced high-density lipoprotein cholesterol) in postmenopausal women (R).
17) Vitamin D has Anti-Inflammatory Role
Studies have shown potent effects of vitamin D on both innate and adaptive immunity.
Effects of vitamin D on immune system include:
- Inhibits B cell production, and antibody secretion (R, R2)
- Decreases T cell growth, inhibits T cell activation and IL-2 production (R, R2)
- Results in a shift from a Th1 to a Th2 phenotype (R, R2)
- Regulates the activity of monocytes/macrophages (R, R2)
- Inhibits dendritic cells production and growth (R, R2)
- Decreases the secretion of inflammatory cytokines IL-1, IL-2, IL-6, IL-8, IL-17, TNF-α, IFN-γ, and IL-12 (R, R2, R3, R4)
- Increases cytokines IL-10 and IL-4 (R, R2, R3, R4)
- Inhibits production of IgE by B cells and enhances production of IL-10 by dendritic cells and T cells, playing an important role in allergic immune responses (R, R2)
- Reduces the expression of MHC class II, CD40, CD80, and CD86 (R, R2)
- Decreases TGF-beta (contributes to tissue repair by promoting tissue fibrosis) (R, R2, R3, R4)
- Crucial for T Cell activation (R)
- Regulates differentiation of CD4+ T cells (decreases Th1 and Th17 cell production, and increases Th2 and Treg cell production) (R, R2)
- Increases CD8+ T Cells, important in controlling viruses, intracellular bacteria, and cancer (R, R2)
- Increases Natural Killer T Cells (R)
- Releases antimicrobials in response to an infection such as cathelicidin and beta defensin 4 (R, R2)
18) Vitamin D May Be Beneficial For Inflammatory Bowel Disease and Celiac Disease
Inflammatory bowel disease (IBD) is a chronic inflammation of the gut, and includes Crohn’s disease and ulcerative colitis.
Studies in mice indicate that this vitamin plays a crucial role in this disease (R).
Vitamin D has an anti-inflammatory effect in patients with IBD.
Study showed a 32% decrease in CRP (C-reactive protein) levels and 46% decrease in ESR (erythrocyte sedimentation rate) in patients receiving vitamin D (R).
1200 IU/d vitamin D supplementation reduced recurrence of Crohn’s disease from 29% to 13% (R).
Low vitamin D level is associated with higher risk of polyps and adenomas in the colon, common complications of ulcerous colitis (R).
Almost 60% of patients with celiac disease were found to be vitamin D deficient or insufficient (R).
19) Vitamin D Plays a Role in Cystic Fibrosis
Low blood vitamin D levels are commonly found in patients with cystic fibrosis (CF).
Its deficiency occurs in 25–33% of patients with late-stage CF (R).
Absorption of this vitamin is reduced in patients with CF due to insufficient pancreatic enzymes (R).
Also, CF patients have increased oxidant and P450 activity, which could lead to faster degradation of vitamin D (R).
95% of cystic fibrosis patients required 1800 IU/day of vitamin D to achieve blood concentration above 25 ng/ml (R).
The information on this website has not been evaluated by the Food & Drug Administration or any other medical body. We do not aim to diagnose, treat, cure or prevent any illness or disease. Information is shared for educational purposes only. You must consult your doctor before acting on any content on this website, especially if you are pregnant, nursing, taking medication, or have a medical condition.
HOW WOULD YOU RATE THIS ARTICLE?