With the cold nights we’ve been experiencing lately, there’s no doubt we are in the middle of winter. When the sun does come out from behind the clouds during this season, it is typically quite weak due to the angle of the Earth. Aside from being able to answer an astronomy pop quiz, how does this affect you? Less sun means less Vitamin D production. You may wonder what Vitamin D does for you, so I’ve listed some of the benefits below:

Cardiovascular

• reduces cardiac hypertrophy (cardiac enlargement)
• reduces myocardial fibrosis (heart tissue scarring)
• protects against vascular calcifications
• lowers the risk of myocardial infarction
• suppresses renin production (this is the kidney hormone that stimulates angiotensin II leading to elevated blood pressures)

Mineral

• increases intestinal calcium and phosphorus absorption

Musculoskeletal

• enhances muscle mass/strength
• maintains normal bone formation

Endocrine

• increases insulin sensitivity
• prevents parathyroid gland hyperplasia (enlargement)
• suppresses parathyroid gland hormone (PTH) synthesis
• stimulates the Vitamin D Receptor (VDR) and the Calcium Senseing Receptor (CaSR) in the parathyroid cells

Immune System

• reduces inflammation
• improves immune function

Kidney (Renal)

• reduces nephrosclerosis/glomerulosclerosis (kidney filter scarring)
• reduces the amount of protein in the urine
• slows down the progression of Chronic Kidney Disease (CKD)
• reduces mortality in patients with CKD and End Stage Renal Disease (ESRD)

Cancer

• promotes cellular differentiation (cell type change)
• inhibits cellular proliferation
• reduces cancer risk and metastatic potential

With all the benefits that Vitamin D can provide, I make sure to supplement with it daily. Now even during the summer, when the sun can activate Vitamin D-3 synthesis, it may be useful to continue to supplement. This is because those with darker skin pigmentation will have a tougher time producing their own Vitamin D. However those with paler skin may also have problems if they wear sunscreen higher than SPF 8, as this will prevent UV absorption.

Further reading: ‘Roid Rage: Vitamin D3 – DO IT (Part I)

WOD 12.28.09
Back Squat
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