Winters coming - Get your Vitamin D
Vitamin D is absolutely essential for optimal health.
Unfortunately, only a handful of foods contain significant amounts of this vitamin, and deficiency is extremely common.
Vitamin D is one of the fat-soluble vitamins (A, D, E and K), meaning that it dissolves in fat/oil and can be stored in the body for a long time.
It is crucial for a number of bodily processes as well as supporting our quest to become awesome at CrossFit! Going into the winter months when sunlight is at a premium, ensuring our vitamin D levels are adequate is crucial.
Functions of Vitamin D
It is well known that vitamin D regulates calcium metabolism and affects various cells related to bone health. But research has now found it to be involved in all sorts of other processes, including -
Increased skeletal muscle function
Decreased recovery time from training
Increase both force and power production
Increase testosterone production
May help prevent seasonal affective disorder (winter blues)
Small amounts of vitamin D can be obtained through the diet in things like mushrooms, eggs, salmon, cod liver oil and fortified milk products. The majority of vitamin D made in the body occurs with exposure to adequate sunlight.
Signs of deficiency
Your skin makes vitamin D when it is exposed to a dose of sunlight. How much vitamin D you make depends on your age, how much skin is uncovered, and your skin tone. Without sunblock and with arms and legs exposed, your skin will make 10,000 to 15,000 units of vitamin D in one pinking sun exposure, on average. (Sunblock with an SPF of more than 15 blocks 100% of vitamin D production in the skin.)
Everyone should have his or her vitamin D level checked at least once a year (infants through the elderly). Below are conditions that have been associated with vitamin D levels:
10 ng/mL Severely deficient
15 ng/mL Risk of rickets
20 ng/mL 75% greater risk of colon cancer
30 ng/mL Deficient
Increased calcium loss from bones, osteoporosis
Poor wound healing
Increased muscle pain
Increased joint and back pain
Greater risk of depression
Increased autoimmune disease (lupus, scleroderma)
30–50 ng/mL Suboptimal levels
34 ng/mL Twice the risk of heart attack
36 ng/mL Increased high blood pressure
40 ng/mL Three times the risk of multiple sclerosis
50–80 ng/mL Optimal levels
50 ng/mL 50% reduction in breast cancer, decreased risk of all solid cancers
80–100 ng/mL Slowing of cancer growth in patients with cancer
150 ng/mL+ Increased risk of toxic symptoms (hypercalcemia)
Vitamin D Supplementation Doses
Normal dosing of vitamin D depends on your blood levels. Treatment doses for blood level ranges are:
10 ng/mL – 10,000 units per day
10–20 ng/mL – 10,000 units per day
20–30 ng/mL – 8,000 units per day
30–40 ng/mL – 5,000 units per day
40–50 ng/mL – 2,000 units per day
If you are taking a vitamin D supplement, adequate calcium and magnesium intake are also required. Vitamin D works well with vitamin K and magnesium both of which are required to assist bone mineral density.
It is very difficult to get too much vitamin D. People can take up to 10,000 units per day for 6 months and not have adverse effects.
Checking Your Vitamin D Level
It is recommended that you recheck your vitamin D level within 2 months after starting supplementation, depending on your medical and health condition.
We use Medichecks to test our clients Vitamin D. Check them out here.
Vitamin D test is £39 and can be done via a finger prick test at home.
PAPERS AND REFERENCES
https://journals.sagepub.com/doi/abs/10.1177/1533210110392952 - Overall health
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3725481/ vitamin D and athletes review
http://www.ncbi.nlm.nih.gov/pubmed/23657931 – vitamin D and performance
http://www.ncbi.nlm.nih.gov/pubmed/23528618 – review effect on athletes
http://www.ncbi.nlm.nih.gov/pubmed/22375241 – potential role on muscle performance