Vitamin D - The sunshine vitamin

Of all the vitamins, Vit.D is receiving significant attention due to revelations about its multiple health giving effects. Also known as the sunshine vitamin it helps build and sustain strong healthy bones, is involved in the function of your muscles, heart, lungs and brain, and is vital to fight infections.  

Vitamin D is known to have an effect on over 2,000 genes in the human body, so it’s no surprise that the strength of your body’s immune system is also tied to how much vitamin D you are taking in. 

Researchers have found that high vitamin D levels are associated with lower risk of diseases, including multiple sclerosis, many types of cancer, cardiovascular disease (congestive heart failure, coronary heart disease, stroke), dementia, dental caries, respiratory tract diseases, metabolic diseases, as well as adverse pregnancy and birth outcomes and “all-cause” mortality rates(1).Just knowing this it is hard to understand why the medical profession isn’t actively doing more about this issue.  

WHAT IT DOES 

Once Vit.D is formed in the skin due to UVB exposure (or consumed in food) it is sent to the liver where it is converted into 25(OH)D. A blood test for Vit.D is actually testing the levels of this substance and should be at least 50ng/mL(4,5). The 25(OH)D is then sent all over your body where it is converted into activated Vit.D (Calcitriol) for various functions(2).   

For strong bones you need calcium and phosphorus, and you need Vit.D to absorb these substances in the gut.  

Calcium is vital in the blood to control your muscles and nerves, and the bones are your body’s store to maintain the correct levels. If your Vit.D is low, then your parathyroid gland acts to pull calcium from your bones to keep blood levels normal. This can lead to bone softening / weakening. So for clarity, too much protection from the sun could lead to osteoporosis- 

In winter the typical (false) alarm bells ring regarding colds and influenza, yet these viruses circulate the entire year. An emerging reality is that a Vit.D deficiency is likely a major reason for the spike in illness, since it plays an important role in the immune system response to fighting off infection. When a vast majority of the population are Vit.D deficient during winter, the chance of getting sick rises. When you look at how your immune system functions it brings the usefulness of a flu-vaccine into question(3).  

Important for you, bone pain, and muscle weakness, or mild symptoms of the diseases mentioned elsewhere in this article could be symptoms of mildly reduced Vitamin D levels. .  

HOW TO GET IT 

Historically we were exposed to sunlight on a daily basis, although weather dependant with varying UVB exposure. Life in the 21st century however is far removed from this outdoors way of living. About 10 different steroid like compounds are made with sun exposure, but the only one we really know anything about is Vit.D  

Vitamin D is the only vitamin that your body can make, but requires sunlight (UVB) on your skin, although you can also take oral supplements (Vit.D3).  All other vitamins you have to eat, but very little Vit.D can be found in foods. 

If you are vegetarian, or more importantly vegan, dietary intake is more difficult since the sources are primarily animal based. This means if your exposure to sunlight is minimal, you’re are more than likely deficient. This has been linked to cancer, asthma, Type II diabetes, high blood pressure, depression, Alzheimer’s, autoimmune diseases like Multiple Sclerosis, Chron’s and Type I diabetes. In the extreme this deficiency can lead to Rickets in children, and osteomalacia in adults.  

If the intention of sunbathing is ONLY to produce Vit.D, then the following is recommended4:  

• sunbathe when your shadow is shorter than you 

• lie for half the time it takes for your skin to turn pink 

• do not use sunscreen during this time 

• over-exposure allows the UV light to destroy the Vit.D already produced  

• UVB tanning lights could be used  to supplement production  

If you are not in the sun the sun, or supplementing in winter, the calculations for recommended dosage are somewhat confusing, as different units are used. For this reason we´ve chosen not to discuss them in detail here, and we welcome your questions directly in the Lounge. 

Since everyone may react differently to sun exposure &/or supplementation, regular testing (for 25(OH)D) is the only way to know if you have the right levels or not. Do not supplement with Vit.D2 as it seems to have minimal beneficial effect. The risk with over-supplementation is hypercalcaemia (elevated blood calcium). If this occurs the symptoms can include nausea, vomiting, anorexia, excessive urination, insomnia, lethargy, nervousness and itching. Hypercalcaemia cannot be caused by excessive sun-exposure. If severe, damage to the liver and kidneys can occur. 

There are many variations on what is considered to be normal Vit.D levels. The 50ng/mL quoted here is higher than what is often otherwise given, sometimes as low as 20-30 is listed as normal. However we feel the holistic perspective argued by the Vitamin D Council5,9 aligns with our philosophy of human health and wellness. If your test result is quoted in different units, convert as follows: x nmol/L : 2,5 = z ng/mL 

Many preparation of Vit.D will combine Vit.K2. The reason is that the Vit.K2 helps with uptake of calcium into the bones. Furthermore, since your body needs Magnesium to be able to use Vit.D, make sure your diet includes food containing Mg. Calcium supplements are seldom recommended now for healthy individuals. 

UVA / UVB 

UVA radiation is present the entire day, and is responsible for tanning and skin ageing. it is also not filtered out by window glass, whereas UVB is. Therefore you can get a tan, especially if you are not in the sun during the middle of the day, and yet still be Vit.D deficient. The only way you can know is by being tested.  

SPECIAL NEEDS 

Whilst it is common for Vit.D levels to drop during pregnancy, given its bone building function there is an increased need for Vit.D then. Once the child is born if the mother is in normal range, then infant supplementation is not necessary. If deficient then Vit.D drops are available for the child.  

Overweight individuals also require more Vit.D.   Oddly the darker your skin the more sun you need to get the same amount of Vit.D as a fair skinned individual.   It would also be safe to assume that if you are over careful with sun exposure i.e. long clothes, no sunbathing, always sunscreen, indoor activities, then you are likely deficient.  

HYPOTHYROIDISM 

The thyroid gland produces 2 hormones essential for a range of bodily functions. When too much is produced (hyper-), the person suffers from a range of symptoms not unlike a constant over-supply of caffeine. In Germany, far more prevalent especially among women is under-function, or the autonomic dysfunction called Hashimoto’s Thyroiditis. The symptoms may include fatigue, Increased sensitivity to cold, constipation, dry skin, weight gain, elevated blood cholesterol level, muscle aches, tenderness and stiffness, heavier than normal or irregular menstrual periods, thinning hair, depression, and impaired memory to name a few.  

A study(9) in 2013 showed a strong correlation between Vit.D deficiency and hypo-function. The researchers were confident enough to say that a deficiency may cause the disease / dysfunction. Additionally that the low levels of Vit.D allows for higher circulating levels of anti-thyroid antibodies which can attack the thyroid gland and therefore diminish its function.     

This does not mean that everyone with hypothyroidism should self-medicate to raise their Vit.D levels, especially if taking thyroid medication. Supplementing with Vit.D may alter or negate the need for the medication, and if excessively consumed potentially cause hypercalcaemia. If your doctor has not considered Vit.D as a line of treatment we strongly recommend asking.     

Much of this may go against what you've heard for years, we look forward to answering your questions on your path to better health.   

REFERENCES  

1. Pludowski P, Holick MF, Pilz S, Wagner CL, Hollis BW, Grant WB, Shoenfeld Y, Lerchbaum E, Llewellyn DJ, Kienreich K, Soni M. Vitamin D effects on musculoskeletal health, immunity, autoimmunity, cardiovascular disease, cancer, fertility, pregnancy, dementia and mortality- a review of recent evidence. Autoimmun Rev. 2013 Aug;12(10):976-89. 

2. Vitamin D, Third Edition by Feldman D, Pike JW, Adams JS. Elsevier Academic Press, 2011. 

3. http://www.nhs.uk/news/2017/02February/Pages/Add-vitamin-D-to-food-to-prevent-millions-of-colds-and-flus-study.aspx 

4. Holick MF. Vitamin D and Health: Evolution, Biologic Functions, and Recommended Dietary Intakes of Vitamin D. In Vitamin D: Physiology, Molecular Biology and Clinical Applications by Holick MF. Humana Press, 2010. 

5. www.vitamindcouncil.org 

6. https://www.youtube.com/watch?v=tQTdBWdqYnU  

7. Holick, M. “Photobiology of Vitamin D.” In Vitamin D, by D Feldman, Pike JW and Glorieux FH, 37-45. Elsevier Academic Press, 2005. 

8. https://www.zentrum-der-gesundheit.de/vitamin-d-ia.html

9. Mackawy AMH et al,Vitamin D Deficiency and Its Association with Thyroid Disease. International Journal of Health Sciences. 2013;7(3):267-275.