Micronutrients & recovery
Vitamin D3 supplementation at doses of 600-800 IU/day is sufficient to maintain skeletal health (calcium homeostasis and bone mineralization) but likely insufficient to prevent chronic non-skeletal diseases, which may require higher serum levels (e.g., >75 nmol/L) achieved by higher doses (e.g., 2000 IU/day).
For most adults, especially those over 50 or with limited sun exposure, taking 600-800 IU of Vitamin D3 daily is the baseline recommendation to support bone health. However, if you are concerned about immune function, muscle strength, or chronic disease prevention, you may need higher doses (e.g., 2000 IU/day) to reach optimal blood levels (>75 nmol/L). Get your levels tested if possible, as dietary sources alone are rarely sufficient.
The triage theory postulates... calcium and bone metabolism can be considered to be secured with highest priority, therefore, it might be speculated that the 600–800 IU intake would satisfy this vitamin D3 serum level threshold. For the chronic non-skeletal diseases however, which have only secondary priority in an evolutionary perspective, higher serum vitamin D3 levels would be required.
Why this rating
Based on a comprehensive review of global data, multiple guidelines, and ongoing large-scale trials, though definitive causal proof for non-skeletal benefits is still pending.
Source
Vitamin D: a critical and essential micronutrient for human health
Igor Bendik et al. · Frontiers in Physiology · 2014
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