Are You Getting Enough Vitamin D? Here’s Why It Matters

By Lucy Sugars, Nutritional Therapist

You may know it as the “sunshine vitamin,” but Vitamin D is actually a hormone — produced in the skin when sunlight hits it. While it’s often mentioned for immune support, a growing body of research shows how vital it is for many areas of our health.

And here’s the issue: most of us aren’t getting enough.

☁️ Why Are So Many People Deficient?

According to the UK’s National Diet and Nutrition Survey, around 90% of the population has insufficient Vitamin D, and up to 20% are severely deficient¹. That’s a huge number.

One major reason? We simply don’t get enough sunlight in the UK — especially between October and April, when our skin can’t make Vitamin D even on sunny days. Long winters, indoor lifestyles, and sunscreen use (while essential for skin safety) also reduce our ability to produce enough.

🧠 Why Vitamin D Is So Important

Low Vitamin D levels have been linked to a wide range of conditions², including:

  • Rickets, osteoporosis, brittle bones
  • Frequent colds, flu, and respiratory infections
  • Eczema, asthma, and other atopic conditions
  • Autoimmune disorders like MS, Type 1 diabetes, Crohn’s disease, and psoriasis
  • Gum and dental issues
  • Low mood and depression
  • High blood pressure and cardiovascular disease

This one nutrient plays a role in bone strength, immune resilience, inflammation, hormone balance, and even mood.

🌞 What About Sunlight?

In summer, 10–15 minutes of full-body sunlight can help the body produce between 10,000–20,000 IU of Vitamin D3 in just one day⁴. Your skin naturally regulates how much it makes — you can’t “overdose” on Vitamin D from the sun, but you can burn, so safe exposure is essential.

🥚 Can You Get Enough From Food?

In theory, yes — but in reality, it’s very difficult. Vitamin D is found in:

  • Oily fish (salmon, mackerel, sardines, herring)
  • Cod liver oil
  • Egg yolks
  • Butter
  • Fortified foods (milk, cereals, plant-based alternatives)

To meet optimal levels (around 2000 IU/day), you’d need to eat oily fish several times daily. Wild salmon, for example, provides up to 1000 IU per 100g, but to correct a deficiency, you’d need much more⁵.

That’s why supplementation and safe sun exposure are often necessary.

💊 How Much Vitamin D Do You Need?

The minimum recommended intake is 600 IU/day for adults

Most people benefit from 1500–2000 IU/day

Never exceed 4000 IU/day from supplements without professional advice

If you’re already taking a multivitamin, collagen blend, or other products containing Vitamin D, it’s important to check the total amount you’re getting.

🧪 Should You Test Your Levels?

Absolutely — my golden rule is test, don’t guess.

Vitamin D levels can be checked with a simple finger prick or blood test, which tells you exactly where you stand. This is especially important if:

  • You’re thinking about supplementing long-term
  • You’ve been taking high doses already
  • You want to optimise your immune, skin, or bone health

I recommend testing every 6 months, or every 3 months if actively working to correct a deficiency.

✅ Final Thoughts

Vitamin D plays a crucial role in your health — from immunity and bone strength to mood, hormones, and gut integrity.
If you’re unsure where your levels stand, or want support choosing the right supplement and dose for you, I’d love to help.

👉 Click here to complete my client intake form and book an appointment.

References:

Nutr Rev. 2008 Oct; 66 (10 Suppl 2):S153-64

Am J Clin Nutr. 2008 Apr; 87(4): 1080S-6S

BMJ. 2010 Jan 11;340:b5664

Pediatrics. 2008 Nov; 122:5

J Clin Endocrinol Metab. 2011 Jul; 96(7): 1911-30