Vitamin D is vital for strong bones and teeth, a healthy immune system, and good mental health. Vitamin D is known as the sunshine vitamin, and because the winters are long and summers are short in northern British Columbia, many people who live in this area are deficient in this crucial nutrient. A lack of direct sunlight in winter means less vitamin D is produced by the body from October to April.
A 2010 study estimated that 37,000 deaths could be prevented every year if the Canadian average vitamin D blood level (25-hydroxycholecalciferol) was 105 nmol/L.
Factors that affect obtaining adequate amounts of vitamin D from sunshine, include the four seasons, the geographic latitude, use of sunscreen (reduces vitamin D synthesis by 99%), dark skin (reduces vitamin D synthesis), age (synthesis decreases by about 75% in a 70 year old), and certain medications.
The 25-OH cholecalciferol test is a blood test, and results of this test fall into one of the following categories:
- severe deficiency (<25 nmol/L)
- mild to moderate deficiency (25 - 80 nmol/L)
- optimal (80 - 200 nmol/L)
- high (200 - 250 nmol/L)
- toxicity possible (>250 nmol/L)
Many people supplement with vitamin D without knowing if what they are taking is too little or too much. Testing guides optimal dosing, especially when high doses of supplemental vitamin D are taken. When high doses of this fat-soluble vitamin are taken, calcium and phosphorus also need to be monitored.
Vitamin D deficiency symptoms include:
- General muscle pain and weakness
- Muscle cramps
- Joint pain
- Chronic pain
- Weight gain
- High blood pressure
- Restless sleep
- Poor concentration
- Bladder problems
- Constipation or diarrhea
- Low immune function
Vitamin D deficiency may play a role in the following diseases:
- Osteoporosis and Osteopenia
- 17 varieties of Cancer (including breast, prostate and colon)
- Heart disease
- High blood pressure
- Metabolic Syndrome and Diabetes
- Autoimmune diseases
- Multiple sclerosis
- Rheumatoid arthritis
- Infertility and PMS
- Parkinson’s Disease
- Depression and Seasonal Affective Disorder
- Alzheimer’s Disease
- Chronic fatigue syndrome
- Chronic Pain
- Periodontal disease and tooth decay
- Ulcerative colitis
It is wise for pregnant and lactating women to have their vitamin D levels measured to help improve the immune health of their babies.