How to identify a nutrient deficiency
Symptom: Symmetric low-back pain.
Possible deficiency: Vitamin D.
Sun exposure generates less vitamin D in darker-skinned people and the elderly. Obesity increases the risk of vitamin D deficiency, too.
What to eat: Salmon, egg yolks, vitamin D-fortified milk, and vitamin D-enhanced mushrooms.
Supplement with: 6,000 IU vitamin D3 daily for eight weeks for deficiency, then 1,500−2,000 IU daily to maintain levels.