Vitamin D aids the body in absorption and maintenance of healthy calcium and phosphate levels, which are critical for bone formation. Without adequate levels, bone growth and maturation would suffer. This deficiency can cause rickets, osteomalacia, and osteoporosis.
Deficiency of Vitamin D is common and often requires a supplement to maintain normal range levels. This is evident worldwide, in men and women of all ages. As a fat-soluble vitamin, we can store our "summer sunshine" Vitamin D, and we can develop toxicity.
Reasons to Take Vitamin D
• Suspected deficiency, as evidenced by poorly mineralized, soft bones, skeletal abnormalities (rickets in children, osteomalacia in adults), pathologic fracture, decreased bone density, compression fractures of spine, and bone pain (osteoporosis)
• Vegan diet without dairy products
• Poor sunlight exposure
Recommended Daily Allowance (RDA)
Vitamin D is not present in most foods. Due to the many variables causing a decrease, Vitamin D levels are often suboptimal. Supplementation is frequently required.
0-6 months: 400IU (10micrograms/day)
7-12 months: 400IU (10mcg/d)
Children (all RDA):
1-3 years: 600IU (15mcg/d)
4-8 years: 600IU (15mcg/d)
Older Children and Adults (all RDA):
9-70 years: 600IU (15mcg/d)
Adults >70 years: 800IU (20mcg/d)
Pregnancy/Breastfeeding: 600IU (15mcg/d)
Safe Upper limits have been set for age groups as follows:
Infants: the upper limit is 1,000 to 1,500IU
Children 1-8years: the upper limit is 2,500-3,000IU
Older children and adults: the upper limit is 4,000IU.
1 mcg of D3= 40 IU of Vitamin D
What If I Take Too Much?
Vitamin D is commonly toxic due to ingesting too much supplement. It is important to get a blood test to document Vitamin D deficiency (25-hyroxyvitamin D level) and the range before starting a supplement for safety reasons. The blood level gives you a start and endpoint for clarity. Levels less than 30nmol/L are too low and above 125nmol/L represent likely toxicity. A level at 50nmol/L is in good range.
Symptoms of Vitamin D toxicity are mostly related to high calcium levels:
• Nausea, vomiting, anorexia, constipation, weight loss, and weakness
• Calcium build-up and deposits in the soft tissues, heart, and lungs
• Kidney stone formation
• Kidney damage
Who Is at Risk for Deficiency?
• Those with strict vegan diet
• People who live in poorly sunlit areas
• Those who do not go outdoors due to work, debility, agoraphobia, etc.
• People who religiously use sunscreen blocks
• Dark skinned people, as they have more melanin pigment ,which blocks Vitamin D formation
• The elderly
• Obese individuals
Natural Food Sources of Vitamin D
Many foods are fortified with Vitamin D, since foods with natural Vitamin D are rare. Milk has 400IU per quart, which is a minimal amount per serving. Some cereals, margarines, juices, and yogurt are fortified with Vitamin D.
The best sources are fatty fish; tuna, salmon, mackerel are rich in Vitamin D.
Beef liver, cheese, and eggs have a very small amount of Vitamin D. Mushrooms have some Vitamin D and are being grown to have higher Vitamin D levels.
Best Ways to Take This Supplement
Vitamin D comes in four forms: D2 (ergocalciferol), D3 (cholecalciferol), calcifediol, and calcitriol. It can be prescribed in much higher doses, to be taken weekly.