The amount of D3 you need can vary from person to person—because let’s face it, we’re all a little different! Some of us just need a bit more sunshine (or supplements) to keep our glow.
Here’s what you need to know to make the best judgment:
Sunlight is Key:
Your skin can produce 4,000 to 10,000 IU of Vitamin D3 in just 10-30 minutes of sun exposure¹. However, if you’re spending more time indoors or live in an area with limited sunlight, you’ll likely need to supplement.
Current Guidelines Are Too Low:
The current recommended daily intake of 400-800 IU is considered too low by many experts. Studies suggest that to reach optimal levels of 25-hydroxy-vitamin D (the form your body uses), you likely need 1.5-6 times more than the current guidelines, which translates to around 2,000 IU per day for adults²,³.
Higher Doses Are Safe:
Research shows that even at doses of 2,000 IU daily, there’s no risk of oversupply, and some people may even need more to achieve optimal levels. Studies have shown that individuals taking 2,000 IU per day do not exceed safe levels, even with adequate sun exposure⁴.
Personalized Doses:
For the most accurate advice, it’s always a good idea to consult a health professional. A blood test is the best way to monitor your Vitamin D levels and adjust your intake accordingly. A more personalized approach recommends 40-60 IU of Vitamin D per kilogram of body weight. So, for a 60 kg (132 lb) person, that would be 2,400-3,600 IU per day⁵.
References:
¹ Gröber, U. & Holick, M.F. (2015). Vitamin D – The Healing Power of the Sun Vitamin (3rd ed.). Stuttgart: Scientific Publishing Company Stuttgart.
² Heaney, R.P. & Holick, M.F. (2011). Why the IOM Recommendations for Vitamin D Are Deficient. Journal of Bone and Mineral Research, 26(3), 455-457.
³ Ross, A.C., Taylor, C.L., Yaktine, A.L. & Del Valle, H.B. (2011). Institute of Medicine – Dietary Reference Intakes for Calcium and Vitamin D. Washington (DC): National Academies Press.
⁴ Heaney, R.P. (2005). The Vitamin D Requirement in Health and Disease. Journal of Steroid Biochemistry and Molecular Biology, 97(1-2), 13-19.
⁵ Gröber, U. & Holick, M.F. (2015). Vitamin D – The Healing Power of the Sun Vitamin (3rd ed.). Stuttgart: Scientific Publishing Company Stuttgart.