Thank you to all for listening in to the Vitamin D talk on Tuesday. As promised here is the summary. Next Tuesdays talk is all about Osteoporosis.
Vitamin D is a fat-soluble nutrient. It is one of the 24 micronutrients critical for human survival
Associated with a wide range of benefits
• increased cognition
• immune health
• heart and muscle function
• important for blood clotting
• helps the body to absorb and use calcium and phosphorus
• bone health
• well-being.
Recommended Dosage:
In July 2016 Public Health England published guidelines for vitamin D:
• Babies from birth to 1 year: 8.5-10ug/day all year round.
• Children over 1 year and adults: 10 ug /day in the winter months (400 IU (10 ug) )
• Pregnant and breastfeeding women and population groups at risk of vitamin D deficiency (those with minimal exposure to sunshine and those from minority ethnic groups with dark skin): 10 ug /day all year round
Sources:
• Full-fat dairy products, oily fish, egg yolks and fortified margarine.
• Vitamin D is also formed by the action of sunlight on the skin (from May to September in the UK).
Food alone is unlikely to provide sufficient vitamin D.
In 2012 the European Food Safety Authority set a safe upper intake level of 100mg for total vitamin D intake
In 2018 the UK food supplements industry set a voluntary safe upper level of 75mg for vitamin D in food supplements which allows for dietary intakes of up to 25mg without exceeding the most widely accepted safe upper level.
Historically, 400 IU (10 ug) of vitamin D was recommended for better health because it closely approximated the amount of vitamin D in a teaspoonful of cod liver oil. However, 800 to 1,000 IU is the dose that may have a better chance of giving a patient a normal vitamin D level.
Deficiency
The body produces vitamin D from cholesterol, provided there is an adequate amount of UV light from sun exposure.
There is only a sufficient amount of UV light coming from the sun when the UV index is 3 or higher, which only occurs year-round near the equator, between the 37th parallels (from May to September in the UK).
Due to the many health benefits of vitamin D, supplementation is encouraged if optimal levels are not present in the body.
Vitamin D deficiency results in poor growth, bone pain and deformities (rickets in children and osteomalacia in adults), osteoporosis, gum disease, constipation and muscle weakness.
Vitamin D and Income
NDNS DATA: OVER 9 YEAR ROLLING PROGRAMME:
Nutrients Intakes of vitamin D significantly increased with increasing income for all or most age/sex groups.
Lowest in all age/sex groups during January to March and more than 20nmol/L higher during July to September.
During January to March
• 19% of children aged 4 to 10 years,
• 37% of children aged 11 to 18 years
• 29% of adults
had 25-OHD below 25nmol/L, the threshold indicating risk of deficiency.
Watch out for interactions/contraindications:
• Anticonvulsants (used to prevent epileptic seizures) may reduce the effect of vitamin D by accelerating its metabolism.
• The weight loss drug orlistat and cholesterol-lowering drugs can reduce the absorption of vitamin D.
• Calcium may increase risk of hypercalcaemia; Vitamin D should be avoided in hypercalcaemia (high levels of calcium in the blood).
Vitamin D and COVID -19
A collaborative team from Trinity College Dublin, the University of Liverpool and the Irish Longitudinal Study on Ageing (TILDA) have been looking at how vitamin D impacts mortality rates among those with coronavirus.
They found the number of deaths were lower among those countries who had higher vitamin D levels.
Research like this is still exploratory and we need further trials to have concrete evidence on the level of vitamin D that is needed for optimal immune function. Until the evidence is confirmed:
Make sure you get enough (but not too much) of each nutrient, preferably from foods rather than supplements.
Supplements are not strictly necessary, and as preventive measures they pale in comparison to physical distancing and diligent hygiene.
If you suspect you have COVID-19, do not rely on supplements to cure you — contact a healthcare professional.
Thank you for taking time to read this!
