Why Supplement Vitamin D?

Vitamin D is synthesized in the body through a reaction involving sunlight. Vitamin D can also be obtained through the diet by consuming fatty fish rich in omega-3, mushrooms, eggs, and supplements. Several recent studies have linked low vitamin D levels to poor bone health, muscle weakness, and deficiencies in sex hormones (estradiol, progesterone, and testosterone).

However, the only health claims authorized by governmental bodies in the United States, Europe, and Canada for vitamin D include reducing the risk of osteoporosis, preventing inflammation, and promoting normal muscle function.

A literature review by Rachele Pojednic and Lisa Ceglia from Tufts University in Boston reports that lower blood levels of vitamin D were linked to decreased aerobic capacity and a higher body mass index. Vitamin D activates genes and cell signaling chemicals that are critical for muscle hypertrophy, muscle strength, and improved performance. In the elderly, maintaining adequate vitamin D levels can contribute to fewer falls. (Exercise Sports Science Reviews, 42: 76-81, 2014)

2) High vitamin D and calcium intake destroys fat cells

Cells have a finite lifespan characterized by cellular growth and death (apoptosis). Obesity researchers are investigating ways to terminate the life of fat cells as a method to reduce body fat.

At the University of South Dakota, a study in rats found that animals fed diets rich in vitamin D and calcium showed decreased body fat, increased blood vitamin D, improved blood sugar regulation, and enhanced markers of fat metabolism. Fat reduction was achieved through increased apoptosis of fat cells. Increasing vitamin D and calcium intake could promote better fat management through cell death, but long-term safety is unknown. (Molecular Nutrition & Food Research, 58: 1342-1348, 2014)

3) Vitamin D deficiency is linked to low fitness levels and obesity. Vitamin D is synthesized in the body through a reaction involving sunlight. Vitamin D can also be consumed in the diet by eating fatty fish, mushrooms, and supplements. Several recent studies have linked low vitamin D levels to poor bone health, muscle weakness, and deficiencies in reproductive hormones. However, the only health claims authorized by governmental bodies in the United States, Europe, and Canada for vitamin D include reducing the risk of osteoporosis, preventing inflammation, and promoting normal muscle function.

Laura Forney of Louisiana State University and her colleagues found that lower blood levels of vitamin D were linked to decreased aerobic capacity and a higher body mass index in college students. Half of the students were vitamin D deficient, with blood levels below 25. The results could be due to reduced physical activity levels in vitamin D-deficient students who do not exercise in the sun. Conversely, low vitamin D levels may impair athletic performance. (Journal Strength Conditioning Research, 28: 814-824, 2014)

Vitamin D is important for bone health, but it may also help prevent some types of rheumatism, cardiovascular disease, depression, and dementia. Australian scientists discovered that vitamin D is also important for testosterone synthesis in testicular cells in the laboratory. They isolated tissue from human testes and added vitamin D, in combination with luteinizing hormone and IGF-1, both of which stimulate testosterone production. The addition of vitamin D enhanced testosterone formation. It is unknown if these results apply to vitamin D supplementation in living individuals. (Journal of Clinical Endocrinology Metabolism, 99: 3766-3773, 2014)

A literature review by Pamela von Hurst and Kathryn Beck from Massey University in New Zealand reported that lower blood levels of vitamin D were linked to decreased aerobic capacity and an increased body mass index. Vitamin D activates genes and cell signaling chemicals that are critical for muscle hypertrophy, muscle strength, and improved performance. In the elderly, maintaining adequate vitamin D levels can contribute to improved muscle mass and physical performance. More studies are needed on the importance of vitamin D in athletes and the potential benefits of supplementation. (Current Opinion Clinical Nutrition Metabolic Care, published online August 23, 2014)

6) Prostate enlargement is linked to vitamin D deficiency

Prostate enlargement is extremely common in aging men, occurring in 50% of men over 50 and 80% of men over 80. Symptoms include incontinence (involuntary urine leakage), frequent urination, straining to urinate, strong and sudden urges to urinate, and incomplete bladder emptying. A literature review conducted by Geovanni Espinosa from New York University School of Medicine concluded that vitamin D deficiency was associated with prostate enlargement. Increased dietary or supplemental vitamin D intake would decrease the risk of this problem. Vitamin D supplements have no side effects and may help prevent this common problem in older men. (Canadian Journal of Urology, 20: 6820-6825, 2013)

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