We know vitamin D as the 'sunshine vitamin'; the main source of it is through the sun. During the summer months, you'll probably be spending more time at the beach or just embracing the heat. Do you still need to supplement?
Why is vitamin D such a superstar? This dose of sunshine:
Acts like a steroid hormone, controlling calcium and phosphate in the body
Supports the immune system
Gives you healthy teeth and bones
Supports muscle strength
Helps regulate your blood sugar levels
Supports your brain and nervous system
Helps you maintain a positive mood
Supports cardiovascular function and lung health
Influences gene expression in relation to cancer development
How do you get enough Vitamin D?
Certain foods do contain some vitamin D, though in such small amounts that it only makes up 5-10% of your requirements.
Foods containing vitamin D:
- Fatty fish
- Egg yolks
- Mushrooms exposed to sunlight
- UVB treated plant-oils
- Foods fortified with Vitamin D
Though you can find it in food, the sun is the best source of vitamin D! When ultraviolet B (UVB) radiation hits your skin, it helps to form a type of vitamin D called vitamin D3 (cholecalciferol). When you cannot naturally reach adequate vitamin D levels, supplementation is recommended.
Can you be deficient even though you go out in the sun?
Statistics show that approximately 25% of Australian adults have varying levels of vitamin D deficiency. If you had your blood checked, it would read a level lower than 50 nmol/L. In summer it should be higher because of the increased sun exposure. However, you can still be deficient even during the hotter months. This can be due to a variety of factors (see below), but also simply because you may not absorb it well. I live on the Gold Coast and even I was low in vitamin D (yes I do go in the sun!).
The challenge with being deficient in vitamin D is that it can be easily mixed up with other potential conditions, or have no symptoms at all! The best way to find out is to order a blood test from your GP. If you feel like you're getting enough sun and you are still low in vitamin D, it's a wise idea to supplement.
A general suggestion is approximately 10-15 minutes of (midday) sunlight per day. However, the recommendations for your local area might be different because of the UV radiation levels.
Pay extra special attention to supplementation if this is you:
You have dark skin: If you live in a colder climate especially, you need to pay attention to vitamin D. Your ancestors probably lived in a hotter climate, and you naturally have higher levels of melanin, which filters UVB and reduces Vitamin D absorption into the skin. The plus side of this is that you're less likely to get sunburnt!
You are overweight: You may have a decreased bioavailability of vitamin D, due to it being deposited in body fat. If it is stuck in body fat, then there is less circulating your blood. Academic research in the link body fat and Vitamin D is ongoing, two questions being: Can low vitamin D leads to higher body fat? Can vitamin D supplementation assist body fat loss? As science advances, we will have clearer answers.
You're shunning the sun: I know you hear everywhere that sun exposure is bad for you, but there's no need to fear the sun - it's the giver of life (and vitamin D!). Of course, you must take care when being outdoors so you're not getting excessive UVA and UVB exposure. Does wearing sunscreen impact on your vitamin D levels? A 2017 international expert panel explored this question and concluded that sunscreen use does not interfere with Vitamin D.
You are over 70 years old: There are numerous vitamin deficiencies to be aware of, including vitamin D deficiency. It's especially important there, considering the increased likelihood of falls and fractures. If you're a senior, intestinal absorption of vitamin D can be an issue, as is the reduced absorption from the sun.
Recommended dosage of vitamin D:
When you have a mild Vitamin D deficiency, Australian guidelines suggest 1000-2000IU of Vitamin D3 supplementation. You may need more, depending on what your health practitioner recommends. Scientific studies suggest 4,000-5000 IUs may be optimal, and to stay under 10,000 IUs. As always, work together with your medical practitioner to find what's correct for you.
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