Movement & Lifestyle

• 30 minutes of outdoor activity daily (important for vitamin D production).
  • Avoid smoking.
  • Limit alcohol intake (<30 g/day).

 Calcium Intake

• Recommended: 1000–1500 mg calcium per day
  • Prefer food sources over supplements

 Calcium-Rich Foods (per 100 g):

 Vegetables with High Calcium Availability:

• Kale, broccoli, watercress – bioavailability up to 50%
  • Spinach, rhubarb, cola, processed meats: contain oxalate or phosphate → inhibit calcium absorption

 Mineral Water Tip:

• >300 mg calcium/liter (e.g., 500 ml = 150 mg)
  • <200 mg sodium/liter and no phosphate

 Avoid Oxalates

• Oxalate-rich foods (e.g., spinach, black tea) can promote kidney stones in susceptible people.
  • Calcium from food binds oxalate in the intestine and prevents calcium oxalate stones.

Vitamin D – For Strong Bones

 Recommended Blood Levels (25-OH-D):

 Dosage Recommendations (e.g. in Osteoporosis):

• 800–1000 IU/day for prevention
  • 2000–4000 IU/day for diagnosed deficiency
  • Long-term use up to 2000–3000 IU/day is generally safe
  • >10,000 IU/day only short term and under medical supervision

 Examples of Vitamin D Products in Europe

 Good to Know

• Daily or weekly dosing is equally effective.
  • Monthly bolus doses (e.g., 100,000 IU) may increase fall risk in older adults.
  • Vitamin D + calcium reduce kidney stone risk when taken through food.

 Vitamin K – Important Companion to Calcium and Vitamin D

 Why Supplement Vitamin K?

 Biochemical Background

1. Osteocalcin Activation
   • Only vitamin K₂ activates osteocalcin, allowing calcium to bind in bone.
2. Vascular Protection
   • Vitamin K activates MGP, which prevents calcium deposits in arteries.
   • Especially important with calcium supplements.

 Vitamin K1 vs. K2

 Studies Show Benefits of K2 (MK-7)

• Improves bone density
  • Reduces arterial calcification
  • Lowers fracture risk
  • Approved as osteoporosis treatment in Japan

 When Is Vitamin K Especially Useful?

• With osteoporosis or calcium/vitamin D supplements
  • In postmenopausal women
  • With vitamin-K-poor diets (e.g., little green vegetables)
  •  Not suitable when taking vitamin K antagonists (e.g., Marcumar®)

 Recommended Daily Combo for Osteoporosis

 Caution with Blood Thinners

 Calcium & Kidney Stones – What to Know

• Calcium from food protects against kidney stones (binds oxalate in the gut).
  • Supplements only with meals to avoid increased kidney excretion.
  • Evidence: Studies (e.g., Curhan et al., AUA guideline) confirm:
  → Calcium-rich diet reduces stone risk.

 Tip: Combo Supplements with K2

Often contain:
• 1000 IU vitamin D3
• 100–200 µg vitamin K2 (MK-7)
• 500–800 mg calcium

Basic Therapy

IV.1 Implementation of Primary Preventive Recommendations

Bone-Healthy Lifestyle:

• Regular physical activity and daily outdoor time (at least 30 minutes)
• Calcium intake: 1000–1500 mg/day, preferably through diet for healthy women
• Avoid harmful substances: No smoking; alcohol <30 g/day

Calcium-Rich Diet / Mineral Water:

• Mineral water should contain at least 150 mg calcium per liter, preferably >300 mg/L, to contribute meaningfully to daily intake.
• Low in sodium (<200 mg/L) and phosphate-free, as excess phosphate inhibits calcium absorption.
• 500 ml of water with 300 mg/L calcium provides 150 mg calcium (~10–15% of daily intake).
• Combine calcium-rich water with calcium-rich foods (e.g., cheese, broccoli, kale).
• Avoid phosphate-rich foods (e.g., cola, meat products), as they hinder calcium absorption.

Calcium-Rich Foods (Per 100 g): Milk and Dairy Products

Vegetables and Fruits

Note on Oxalates:

• Oxalate-rich foods (e.g., spinach, black tea) can bind with calcium and form kidney stones.
• The bioavailability of calcium matters more than absolute content:
  • ~5% for spinach, rhubarb, potatoes
  • ~20% for nuts, seeds, beans
  • ~30% for dairy products
  • ~50% for broccoli, cauliflower, Brussels sprouts, watercress, Chinese cabbage, kale

Sweets (Per 100 g):

Black Tea:

• Contains high oxalate (910 mg)
• Reduces calcium absorption and should be avoided by individuals with oxalate stones

Calcium & Kidney Stones:

• Calcium from food lowers kidney stone risk by binding oxalate in the gut
• Calcium supplements may raise risk if taken without meals

Vitamin D Deficiency (Global Context):

• WHO considers <50 nmol/L as insufficient

Vitamin D Status Classification (25(OH)D in Blood):

Vitamin D Recommendations (Europe):

• 800–1000 IU/day for osteoporosis prevention
• 2000–4000 IU/day for deficiency treatment
• Long-term dosing up to 3000 IU/day often needed for sufficiency
• Doses >10,000 IU/day safe short-term but not for long-term use

Vitamin D Preparations (Examples):

Best Practice:

• Daily or weekly dosing equally effective
• Monthly bolus doses may increase fall risk in older adults

Vitamin D & Calcium Together:

• Vitamin D enhances calcium absorption
• Calcium is essential for bone mineralization
• Most adults need 1000–1200 mg calcium/day
• Most Europeans only get 500–800 mg/day from diet
• Supplementing 500–1000 mg often necessary

Vitamin K in Bone & Vascular Health:

Key Roles of Vitamin K:

• Activates osteocalcin (incorporates calcium into bone)
• Activates Matrix-GLA-Protein MGP (prevents arterial calcification)
• Complements vitamin D and calcium

K2 vs. K1:

• K1 (phylloquinone): works mainly in the liver (blood clotting)
• K2 (menaquinone, especially MK-7): targets bone and vessels

When to Consider K2:

• High calcium/Vitamin D intake
• Osteoporosis or high cardiovascular risk
• Postmenopausal women
• Low green vegetable intake
• NOT for those on vitamin K antagonists (e.g., warfarin)

Recommended K2 Dosages:

Suggested Combo for Osteoporosis:

Caution with Blood Thinners:

• Do NOT supplement vitamin K with vitamin K antagonists (e.g., Marcumar) without medical advice
• NOACs (e.g., Apixaban, Rivaroxaban) generally not affected, but check with a doctor

Kidney Stones & Vitamin D:

• Normal vitamin D: no increased risk
• High doses + calcium supplements: potential risk
• Mechanism: more calcium absorbed → excreted in urine → stone formation

Conclusion:

• Balanced intake of calcium, vitamin D, and vitamin K supports bones and protects vessels
• Food-based calcium is protective against stones
• Supplements must be timed and dosed appropriately

Can Vitamin D Cause Kidney Stones?
Yes – but only under certain conditions. A normal vitamin D level or moderate supplementation is generally safe. The risk of kidney stones increases especially if:

• Too much vitamin D is taken (high-dose over a long period).
• Large amounts of calcium are supplemented at the same time (not via food).
• There is a predisposing metabolic condition (e.g., genetic hypercalciuria).

 How Does It Work? (Pathophysiology)
Vitamin D increases calcium absorption from the gut → more calcium enters the bloodstream → the excess is excreted by the kidneys → higher calcium levels in the urine (hypercalciuria) → increased risk of calcium stones (mainly calcium oxalate stones).

What Do Studies & Guidelines Say?
Women’s Health Initiative (WHI) Study:
• Women who took 1000 mg calcium + 400 IU vitamin D had a slightly increased risk of kidney stones.
• However, the increase was small and not present in all individuals.

 Other Studies:
• Moderate vitamin D intake (e.g., 800–2000 IU/day) is not clearly associated with increased risk.
• High-dose therapies (e.g., >10,000 IU/day) over long periods can increase the risk, especially when combined with calcium supplements.

 Practical Summary

 Recommendations

• Avoid high-dose therapy >4000 IU/day without medical supervision.
• Prefer calcium from food rather than supplements.
• Drink plenty of fluids (2–2.5 liters/day) to dilute the urine – this significantly reduces stone risk.

In the past, it was actually believed that vitamin D (especially in high doses in newborns) could cause subaortic stenosis or supravalvular aortic stenosis (SVAS). However, this view is now considered outdated.

Origin of This Claim
The theory stems from older animal studies and clinical observations from the 1950s to 1970s:
• Animal studies (mainly in dogs and rabbits) showed that extremely high doses of vitamin D led to vascular calcifications and cardiac changes.
• There were reports that infants who received vitamin D prophylaxis later presented with heart defects like supravalvular aortic stenosis.
• At the time, vitamin D overdosing was more common due to poor dosage standards.

 Today’s Known Cause: Williams-Beuren Syndrome
What was once thought to be vitamin D-induced stenosis is now known, in many cases, to be a genetic disorder:
• Williams-Beuren syndrome → genetically caused disorder (deletion on chromosome 7q11.23)
• Characteristic features: supravalvular aortic stenosis, facial dysmorphisms, hypercalcemia
• Children with Williams syndrome often have increased sensitivity to vitamin D, which leads to hypercalcemia – this was previously misinterpreted as a result of vitamin D, rather than a genetic cause.

 Current Scientific Consensus
• Normal vitamin D intake (as currently recommended in infant prophylaxis) does not cause subaortic or supravalvular stenosis.
• There is no proven link between vitamin D and heart defects.
• The historical connection was based on outdated or incorrect interpretations.

Conclusion
• The earlier assumption that vitamin D causes subaortic stenosis has been scientifically disproven.
• In most cases, the cause was genetic (e.g., Williams syndrome).
• Normal vitamin D supplementation in infancy is safe and necessary – for example, to prevent rickets.