Metric system. Metric system, international decimal system of weights and measures, based on the metre for length and the kilogram for mass, that was adopted in France in 1795 and is now used officially in almost all countries.
However, if taken in large doses, vitamin D side effects may include: Thirst; Metallic taste in the mouth; Increased urination; Decreased appetite; Weight loss; Constipation; Vomiting; Diarrhea; Itchy skin; Loss of muscle tone; Irritability; Tiredness; Sore eyes; Pain in the bones and joints ...
Safe sun exposure is the best way to optimize your vitamin D levels, but a safe tanning bed, or a vitamin D3 supplement, can also be used. Other important nutrients for eye health include astaxanthin, lutein, zeaxanthin, bilberry, black currant and omega-3 fats.