W7-L3: Vitamin D Flashcards
RESTUDY THE FAT SOLUBLE VITAMINS
What are the Functions of Vitamin D?
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- Bone Health & Reduced Fracture Risk
- Cell Growth & Muscle Function
- Healthy Immune System
- Cardiovascular Health
- Cancer Prevention
- Mental Health
How does Vitamin D aid in
Bone Health & Reduce Fracture Risk?
crucial for calcium absorption in the gut, which helps maintain bone density and reduces the risk of fractures and conditions like osteoporosis
How does Vitamin D aid in
Cell Growth & Muscle Function?
- helping reduce the risk of muscle weakness
and falls in older adults - Essential for cell differentiation and growth, which is important for tissue repair & maintaining overall body function
How does Vitamin D aid in
Immune Function?
- Plays a key role in modulating immune responses, helping to fight infections
- reducing the risk of autoimmune diseases.
- May help in preventing or reducing chronic inflammation
How does Vitamin D aid in
Cardiovascular Health?
- Emerging evidence suggests that adequate vitamin D levels
may help reduce the risk of heart disease, hypertension, and stroke. - It may help regulate blood pressure and vascular health
How does Vitamin D aid in
Cancer Prevention?
Research has linked higher vitamin D levels with a lower risk of certain cancers, particularly colorectal cancer
How does Vitamin D aid in
Mental Health?
Low levels of Vitamin D have been associated with a high risk of depression, anxiety, & seasonal affective disorder (SAD).
What are sources of Vitamin D?
What is the best source of Vitamin D?
10-30 minutes of SUN exposure on the face, arms, hands, etc is enough
Is Vitamin D3 the only type of VD?
There is also a Vitamin D2 but it is not as bioavailable
What is the RDA for Vitamin D?
RDA = 600IU M & F
IU = International Units
What are Common Causes of
Vitamin D Deficiency?
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- Geographical Location
- Season & Sunlight Exposure
- Skin Exposure
- Skin Pigmentation
- Body Fat Levels
- Age
- Dietary Intake & Health Conditions
How can Geographical Location lead to
Vitamin D Deficiency?
At latitudes above 35°N or 35°S (e.g., northern parts of NA, Europe, & most of Asia), UVB exposure is insufficient during the winter months to produce adequate Vitamin D.
UVB radiation is too weak to penetrate the atmosphere effectively, limiting the skin’s ability to make Vitamin D
How can Season & Sunlight Exposure lead to Vitamin D Deficiency?
Limited outdoor activity during the colder months can further reduce exposure to sunlight, affecting overall Vitamin D synthesis
How can Skin Exposure lead to
Vitamin D Deficiency?
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- Clothing & sunscreen can block UVB rays, reducing the skin’s ability to produce Vitamin D.
- Sunscreen with SPF 30 or higher can reduce Vitamin D synthesis by up to 95% or more.
- The more skin exposed to sunlight, the more Vitamin D the body can produce. But most people do not get adequate exposure due to clothing or lifestyle choices.
How can Skin Pigmentation lead to
Vitamin D Deficiency?
- Melanin, the pigment in darker skin, reduces the skin’s ability to produce Vitamin D from sunlight.
- People with darker skin (e.g., African or Afro-Caribbean descent) require longer sun exposure to produce the same amount of Vitamin D as someone with lighter skin
How can Body Fat Levels lead to
Vitamin D Deficiency?
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- Higher body fat can reduce bioavailability of VD.
- Vitamin D is fat-soluble, so it can be stored in fat tissue, limiting the amount available in bloodstream for use by body.
- Obesity is associated with lower levels of circulating Vitamin D, even when dietary intake is adequate.
How can Age lead to
Vitamin D Deficiency?
- Older adults often have decreased skin thickness & reduced ability to synthesize VD from sunlight.
- Additionally, older adults tend to have lower sun exposure and may be more likely to use sunscreen or cover up when outside.
How can Dietary Intake lead to
Vitamin D Deficiency?
While sunlight is the primary source of Vitamin D, food sources (like fatty fish, fortified dairy, and supplements) can help boost levels
How can Health Conditions lead to
Vitamin D Deficiency?
Certain conditions like celiac disease, Crohn’s disease, or kidney disease can impair Vitamin D absorption or conversion.
What is considered an insufficient store of Vitamin D?
What % of Canadians are thought to be at this level?
- Insufficient store < 50nmol/L
- 32% of Canadians had insufficient vitamin D
- This increases to 40% in the winter months
What is considered a deficient store of Vitamin D?
What % of Canadians are thought to be at this level?
- deficiency = < 30nmol/L
- 10% were deficient
What Groups of Canadians had the lowest Vitamin D Levels?
- Canadians aged 20 to 39 had the lowest rates of sufficient vitamin D levels
- Overweight / obese individuals
What are the supplemental recommendations for Vitamin D?
Mixed recommendations
- Health Canada: 600IU/day
- Endocrine society: 1,500 – 2,000IU/day
- Osteoporosis Canada: 1,000 - 2,000IU per day
Most individuals taking 1,000IU per day (good for winter)
What is the UL for Vitamin D?
UL = 4,000IU / d
NOAEL = 10,000IU /d
NOAEL = No Observed Adverse Effect Level
can also take a very high dosage once a week instead of daily
What can excess VD lead to?
Toxicity = hypercalcemia, hypercalciuria, kidney stones, soft tissue calcification
How should you take Vitamin D Supplements?
Supplements: well absorbed with meal that contains fat, recommended during winter months
